EP1594983A2

EP1594983A2 - Use of a novel polymorphism in the hsgk1 gene in the diagnosis of hypertonia and use of the sgk gene family in the diagnosis and therapy of the long qt syndrome

Info

Publication number: EP1594983A2
Application number: EP04708317A
Authority: EP
Inventors: Florian Lang; Andreas Busjahn
Original assignee: Individual
Current assignee: Individual
Priority date: 2003-02-07
Filing date: 2004-02-05
Publication date: 2005-11-16
Also published as: WO2004070057A3; KR20050118672A; ZA200506283B; RU2005127807A; CN1761760A; BRPI0407292A; MXPA05008329A; US20080015141A1; AU2004209609A1; WO2004070057A2; DE10305213A1; JP2006520587A; CA2515339A1; PL378400A1

Abstract

The invention relates to the use of single- or double-stranded nucleic acids that contain a fragment of the hsgk in the diagnosis of hypertonia. The said fragment has a minimum length of 10 nucleotides/base pairs and the said fragment further comprises a polymorphism which is the result of the presence or absence of an insert of the nucleotide G in position 732/733 in intron 2 of the hsgk1 gene. The invention also relates to the use of the direct correlation between overexpression or the functional molecular modification of human homologues of the sgk family and the length of the Q/T time in the diagnosis of the Long QT syndrome, and to the use of the nucleic acid of a human homologue of the sgk gene family or of one of its fragments in the diagnosis of the Long QT syndrome. Polymorphisms of single nucleotides (single nucleotide polymorphisms = SNP) in the human homologues of the sgk gene family are especially useful in the diagnosis of a congenital predisposition for the Long QT syndrome. In another aspect, the invention relates to the use of a functional activator or a transcriptional factor which boosts expression of the genes of the sgk family for producing a drug for use in the therapy and/or the prophylaxis of the Long QT syndrome.

Description

Use of a new polymorphism in the hsgkl gene for diagnosis of hypertension and use of the sgk gene family for diagnosis and therapy of

Long-Q / T syndrome

The present invention relates to the use of a single-stranded or double-stranded nucleic acid containing a fragment of the hsgk for the diagnosis of hypertension, the said fragment being at least 10 nucleotides / base pairs long and the said fragment further comprising a polymorphism which results from the presence or Absence of an insertion of nucleotide G at position 732/733 in intron 2 of the hsgkl gene results.

The present invention further relates to the use of the direct correlation between the overexpression or the functional molecular modification of human homologs of the sgk family and the length of the Q / T time for the diagnosis of Long Q / T syndrome, and the use of the nucleic acid a human homologue of the sgk gene family or one of its fragments for the diagnosis of Long-Q / T syndrome. In particular, polymorphisms of single nucleotides (single nucleotide polymorphisms = SNP) can also be used in the human homologues of the sgk gene family for the diagnosis of a genetic predisposition to Long-Q / T syndrome.

In a further aspect, the invention relates to the use of a functional activator or a transcription factor which increases the expression of the genes of the sgk family for the manufacture of a medicament for the therapy and / or prophylaxis of Long-Q / T syndrome.

Numerous extracellular signals lead to intracellular phosphorylation / dephosphorylation cascades in order to ensure rapid transmission of these signals from the plasma membrane and its receptors into the cytoplasm and the cell nucleus. The specificity of these reversible signal transduction cascades is made possible by a large number of individual proteins, in particular kinases, which transfer a phosphate group to individual substrates. The serum and glucocorticoid-dependent kinase (sgk), a serine / threonine kinase, the expression of which is increased by serum and glucocorticoids, was first cloned from rat breast cancer cells (Webster et al., 1993). The human version of the sgk, the hsgkl, was cloned from liver cells (Waldegger et al., 1997). It was shown that the expression of the hsgkl is influenced by the regulation of the cell volume. Such a dependence on the cell volume has so far not been demonstrated for the expression of the rat sgk. Furthermore, it was found that the rat kinase stimulates the epithelial Na ⁺ channel (ENaC) (Chen et al, 1999; Naray-Pejes-Toth et al, 1999). The ENaC in turn plays a crucial role in renal Na excretion. An increased activity of the ENaC leads to an increased renal retention of sodium ions, and in this way to the development of hypertension, as shown by WO02 / 074987 A2.

Finally, two other members of the human sgk gene family were cloned, the hsgk2 and hsgk3 (Kobayashi et al., 1999), both of which - like the hsgkl - are activated by Insμlin and IGF1 via the PI3 kinase pathway. Electrophysiological experiments showed that coexpression of the hsgk2 and hsgk3 also resulted in a significant increase in the activity of the ENaC.

DE 197 08 173 AI shows that the hsgkl is a considerable diagnostic tool in many diseases in which cell volume changes play a decisive pathophysiological role, such as, for example, hypernatremia, hyponatremia, diabetes mellitus, renal insufficiency, hypercatabolism, hepatic encephalopathy and microbial or viral infections Has potential.

It has been described in WO 00/62781 that the hsgkl activates the endothelial Na ⁺ channel, which increases renal Na ⁺ absorption. Since this increased renal Na ⁺ absorption is associated with hypertension, it was assumed here that an increased expression of the hsgkl should lead to hypertension, a reduced expression of the hsgkl should ultimately lead to hypotension.

DE 100 421 37 also describes a similar relationship between the overexpression or overactivity of the human homologues hsgk2 and hsgk3 with the overactivation of the ENaC, the resulting increased renal Na absorption and the hypertension that develops from this. Furthermore, the diagnostic potential of the kinases hsgk2 and hsgk3 regarding arterial hypertension has already been discussed. WO02 / 074987 A2 discloses the relationship between the occurrence of two different polymorphisms (single nucleotide polymorphism (SNP)) of individual nucleotides in the hsgkl gene with a genetic predisposition to hypertension. This is a polymorphism in intron 6 (T—> C) and a polymorphism in exon 8 (C → T) in the hsgkl gene. Table 5 from WO02 / 074987 A2 shows in particular that there is a strong correlation imbalance between the two SNPs analyzed: Most CC carriers of the SNP in exon 8 are also intron 6 TT carriers (namely 64%), while only a few exons 8 TT carriers are also intron 6 CC carriers (only 2%). These observed correlations between the occurrence of the polymorphisms in intron 6 and exon 8 justify the need to analyze the genotype for both polymorphisms (intron 6 and exon 8) in order to demonstrate a predisposition to hypertension, which leads to a high technical and time expenditure.

The object of the present invention is therefore to provide a further polymorphism in the hsgkl gene, the occurrence of which in one version or the other may correlate even better with the phenotypic occurrence of hypertension in the patient than the two known polymorphisms in exon 8 and intron 6. In particular it would be of great advantage to provide a single SNP that correlates with the predisposition to hypertension and whose presence in one version or another even has consequences for a functional molecular modification of the hsgkl protein.

This object was achieved by providing a new polymorphism in the hsgkl gene, which consists of the insertion of the nucleotide G at position 732/733. It has been shown that individuals who insert such nucleotide G at the position

732/733 (InsG / InsG), occur more frequently and have a lower predisposition to

Have hypertension training. Individuals who, on the other hand, have such an insertion on the

Do not have position 732/733 (WT / WT), occur less frequently and have a significantly increased predisposition to develop hypertension. According to the results so far, this correlation between the genotype and the polymorphism appears

Position 732/733 in intron 2 and the predisposition to hypertension to have a significantly higher significance than the corresponding correlations with regard to the

Polymorphisms in exon 8 and intron 6 (see Table 1). Furthermore, based on the prediction of known prediction programs, it can be assumed that the expression of a specific splice variant of the hsgkl gene depends on the presence or absence of the G insertion at position 732/733 in intron 2 of the hsgkl gene. The expression of such a specific splice variant of the hsgkl gene could result in a functional molecular modification of the hsgkl protein, which leads to a modified activity of the hsgkl, in particular to an increased activity of the hsgkl. The physiological consequences of this molecular modification of the hsgkl protein, in particular an increased activity of the hsgkl, could ultimately result in the development of the symptoms of hypertension.

In a first aspect, the invention relates to the use of an isolated single- or double-stranded nucleic acid which contains a fragment of the nucleic acid sequence according to SEQ ID No. 1 or according to SEQ ID No. 2 comprises, for the diagnosis of hypertension, wherein said fragment is at least 10 nucleotides / base pairs, preferably at least 15 nucleotides / base pairs, in particular at least 20 nucleotides / base pairs long, and wherein said fragment has the polymorphism in intron 2 of the hsgkl gene either with or without the insertion of nucleotide G at position 732/733.

SEQ ID No. 1 describes the genomic DNA sequence of the hsgkl without the insertion of the nucleotide G (or GTP) at position 732/733 in intron 2 of the hsgkl gene, which describes the so-called “wild type (WT)” sequence and SEQ ID No. 2 the genomic DNA sequence of the hsgkl with the insertion of the nucleotide G (or GTP) at position 732/733 in intron 2 of the hsgkl gene, the so-called “insertion G (InsG)” sequence.

In a second aspect, the present invention relates to a kit for diagnosing hypertension, comprising at least one isolated single- or double-stranded nucleic acid which contains a fragment of the sequence according to SEQ ID No. 1 or 2 includes. The said fragment from SEQ ID No. 1 or 2 is at least 10 nucleotides / base pairs, preferably at least 15 nucleotides / base pairs, in particular at least 20 nucleotides / base pairs. Furthermore, said fragment from SEQ ID No. 1 or 2 comprise the polymorphism in intron 2 of the hsgkl gene either with or without the insertion of nucleotide G at position 732/733.

Alternatively, the kit for the diagnosis of hypertension — in addition to or instead of the single or double-stranded nucleic acid mentioned above — may also contain at least one antibody which is directed against such a region of the hsgk protein whose presence in the hsgkl protein is dependent on the presence of the insertion of nucleotide G at position 732/733 in intron 2 of the corresponding coding hsgk gene. For example, if the presence of the G insert at position 732/733 in the hsgkl gene induced the splicing of an exon, an antibody directed against precisely this spliced-out protein region could be used to detect the polymorphism version of the individual , With such an antibody, a predisposition to develop hypertension could therefore be diagnosed.

In a third aspect, the invention relates to a method for diagnosing hypertension, which comprises the following method steps: a) taking a body sample from an individual, b) optionally isolating and / or amplifying genomic DNA, cDNA or mRNA from the body sample according to a) , c) Quantification of alleles which have an insertion of nucleotide G at position 732/733 in intron 2 of the hsgkl gene.

In step a), a body sample is taken from a test individual, who is preferably a mammal, in particular a human. In this diagnostic method according to the invention, blood samples or also saliva samples are preferably used as body samples of the patient, which comprise cellular material and can be obtained by the patient with relatively little effort. However, other body samples that also include cells, such as tissue or cell samples, etc., can also be used.

In step b), either genomic DNA or cDNA or also mRNA is prepared from the body sample from a) using standard methods (Sambrook-J and Russell-DW (2001) Cold Spring Harbor, NY, CSHL Press) and / or optionally amplified. All suitable methods known to the person skilled in the art can be used here. This DNA isolation step or DNA amplification step can optionally also be dispensed with, in particular if detection methods are used in step c) which themselves contain a PCR amplification step.

In step c) the number of alleles is finally quantified which have an insertion of the nucleotide G at position 732/733 in intron 2 of the hsgkl gene. Individuals who have two WT alleles are likely to be predisposed to training of hypertension. The quantification / identification of the alleles with regard to the polymorphism at position 732/733 in intron 2 of the hsgkl gene can be carried out using various methods which are known to the person skilled in the art. Some preferred methods are explained in more detail below. However, the quantification of the number of alleles that have an insertion of nucleotide G at position 732/733 in intron 2 of the hsgkl gene is not limited to the preferred methods below.

Preferably, the genotype (or the number of alleles) can be identified with respect to the polymorphism at position 732/733 by direct sequencing of the DNA, preferably the genomic DNA, from the body sample at said position 732/733 in intron 2 of the hsgkl gene , For this, short oligonucleotides with sequences from the vicinity of position 732/733 of the hsgkl gene must be made available as sequencing primers according to known sequencing methods.

Another, likewise preferred method for identifying the genotype (or for quantifying the number of alleles) with regard to the polymorphism at position 732/733 are all known methods which are based on the hybridization of the genomic DNA from the body sample with specific hybridization probes.

An example of such a hybridization method is e.g. the southern blot. If, for example, the presence of the G insert at position 732/733 in intron 2 of the hsgkl gene destroys or also forms an interface for a restriction endonuclease, nucleic acid fragments with lengths that differ from the corresponding fragment lengths in the WT alleles differ. A specific genotype could thus be detected with regard to the polymorphism in question at position 732/733.

If the presence or absence of the G insertion at position 732/733 expresses an alternative splice variant that lacks a specific exon, the genotype for the polymorphism in question at position 732/733 could also be determined with the help of a specific hybridization probe Splice variant missing exon can be detected. Another example of a hybridization method is the hybridization of the genomic DNA from the body sample with a labeled, single-stranded oligonucleotide, preferably 15-25 nucleotides in length, which either has a G insertion at position 732/733 or does not have it. Under very specific hybridization conditions that can be tested experimentally for each individual oligonucleotide by known methods, a completely hybridizing oligonucleotide can then be distinguished from an oligonucleotide with a single base mismatch.

Further preferred methods for identifying the genotype (or for quantifying the number of alleles) with regard to the polymorphism at position 732/733 are, in particular, the PCR oligonucleotide elongation assay or the ligation assay.

In the PCR oligonucleotide elongation assay, for example, an oligonucleotide could be provided which contains the sequence of a fragment from SEQ ID No. 2 and at its 3 'end has the G at polymorphism position 732/733. If this oligonucleotide was hybridized with a sample fragment of the WT allele (without G insertion), this could not be extended and ultimately amplified in a subsequent PCR reaction due to the mismatch at the 3 'end. When this oligonucleotide is hybridized with an InsG allele, on the other hand, due to the perfect base pairing at the 3 'end of the oligonucleotide, elongation and ultimately a PCR amplification product could result.

A ligation assay is ultimately based on the same principle as the PCR oligonucleotide elongation assay: only those double-stranded nucleic acid fragments can be ligated to another double-stranded nucleic acid fragment that have an exact base pairing at the end. The occurrence of a specific ligation product can therefore be made dependent on the presence or absence of the G insertion at position 732/733 in intron 2 of the hsgkl gene.

In addition to the correlation of the polymorphism according to the invention to the predisposition of hypertension, a second correlation of the polymorphism according to the invention to the length of the so-called Q / T time was surprisingly found. Individuals who have a WT / WT genotype with regard to position 732/733 in intron 2 of the hsgkl gene show significantly shorter Q / T times than for individuals who have an InsG / InsG genotype. Heterozygous individuals (WT / InsG) have medium Q / T Times (see table 3). A significantly prolonged Q / T time leads to the development of the so-called Long Q / T syndrome, which can manifest itself in cardiac arrhythmias, ventricular fibrillation and sudden cardiac death. Individuals with the InsG / InsG genotype are therefore likely to be predisposed to the development of the Long-Q / T syndrome.

Due to the proven direct correlation between the length of the Q / T time and the genetic makeup of the hsgkl gene, in particular between the length of the Q / T time and the polymorphism at position 732/733 in intron 2 of the hsgkl gene, to assume that nucleic acids from another human homologue of the sgk family are also suitable for the diagnosis of Long-QT syndrome.

The Q, R and S waves that can be detected with the ECG measuring device represent measured values for assessing the spread of excitation. The so-called Q / T time is defined as the time that elapses with the help of an EKG measuring device from the start of the spread of the T - Wave (the occurrence of the Q deflection) is to be detected until the end of the excitation propagation, which is characterized by the end of the T wave. The Q / T time thus represents the time that passes between the beginning of a new state of excitation of the heart and the return to the resting state. A significantly longer Q / T time therefore leads to cardiac arrhythmias and ultimately to the Long Q / T syndrome mentioned above.

The invention therefore furthermore relates to the use of the direct correlation between the overexpression or the functional molecular modification of human homologs of the sgk family, in particular the hsgkl gene, and the length of the Q / T time for diagnosing the Long-QT syndrome.

In this context, a human homologue of the sgk family, which comprises a functional molecular modification in the above sense, means a homologue of the sgk family which is mutated in such a way that the properties, in particular the catalytic properties or the substrate specificity of the corresponding protein can also be changed.

The direct correlation according to the invention between the Q / T time and the genetic one

Equipment of the human homologues of the sgk family implies that individual mutations in the genes hsgkl, hsgk2 or hsgk3 could occur in individual patients, which alter the level of expression or the functional properties of the kinases hsgkl, Modify hsgk2 or hsgk3, and thus lead to a genetically caused extension of the Q / T time and ultimately to a predisposition to the development of Long Q / T syndrome. Such mutations could occur, for example, in the regulatory gene regions or also in intron sequences of the sgk gene locus. On the other hand, individual differences in the genetic makeup of the sgk locus could also affect the coding gene area. Mutations in the coding region could then possibly lead to a functional change in the corresponding kinase, for example to modified catalytic properties of the kinase, which ultimately also influence the Q / T time. Accordingly, both types of mutation described above could cause an extension of the Q / T time and thus ultimately the predisposition to the development of the Long Q / T syndrome.

The mutations described above in the human homologs of the sgk family, which predispose to the development of Long-Q / T syndrome in the patient, are usually so-called "single nucleotide polymorphisms" (SNP) either in the exon or in the intron -Barea of these homologues. SNPs in the exon region of the hsgk genes can, in their less frequently occurring version - hereinafter referred to as the mutated version - possibly lead to amino acid exchanges in the corresponding hsgk protein and thus to a functional modification of the kinase. SNPs in the intron region or in regulatory sequences of the hsgk genes can, in their mutated version, possibly lead to a change in the expression level of the corresponding kinase. However, SNPs in the intron region could also lead to a functional modification of the kinase if they influence the alternative splicing of the immature mRNA.

Another object of the invention relates to the use of a single- or double-stranded nucleic acid which comprises the sequence of a human homologue of the sgk family or one of its fragments, in particular the hsgkl gene itself or one of its fragments, for the diagnosis of a predisposition to the formation of the long -Q / T syndrome. The single- or double-stranded nucleic acid is preferably at least 10 nucleotides / base pairs in length.

In addition to the single-stranded or double-stranded nucleic acids mentioned above, certain antibodies which are directed against substrates of the human homologues of the sgk family, in particular against substrates of the hsgkl, are also suitable for diagnosing a predisposition to the formation of Long-Q / T syndrome and hypertension. This diagnostic Antibodies are preferably directed against such an epitope of the human homologues of the sgk family, in particular the hsgkl, which contains the phosphorylation site of the substrate either in phosphorylated form or in non-phosphorylated form.

In a preferred embodiment, the ubiquitin protein ligase Nedd4-2 (Acc No. BAA23711) is used as the substrate of the human homologue of the sgk family. This ubiquitin protein ligase is a protein which is specifically phosphorylated by the human homologues of the sgk family [Debonneville et al., Phosphorylation of Nedd4-2 by Sgkl regulates epithelial Na (+) channel cell surface expression. EMBO J., 2001; 20: 7052-7059; Snyder et al., Serum and glucocorticoid-regulated kinase modulates Nedd4-2-mediated inhibition of the epithelial Na (+) channel. J. Biol. Chem., 2002, 277: 5-8]. Phosphorylation sites for the hsgkl have the consensus sequence (R X R X X S / T), where R is arginine, S is serine, T is threonine and X is any amino acid. In Nedd4-2 (Acc No. BAA23711) there are two potential hsgkl phosphorylation sites to which the above consensus sequence fits: the serine at amino acid position 382 and the serine at amino acid position 468.

The abovementioned antibodies for diagnosing a predisposition to the formation of the Long-Q / T syndrome are therefore preferably directed against the substrate Nedd4-2 and particularly preferably against a protein region of Nedd4-2 with the sequence of the potential phosphorylation site for the hsgkl, the consensus Sequence (RXRXXS / T). In particular, these antibodies are directed against those Nedd4-2 protein regions which comprise at least one of the two potential phosphorylation sites serine at amino acid position 382 and / or serine at amino acid position 468.

Another object of the invention is a kit for the diagnosis of Long-QT syndrome or other diseases which manifest themselves in an extension of the Q / T time. This kit for the diagnosis of Long-QT syndrome preferably contains antibodies, or in particular, directed against the human homologs of the sgk protein family

Nucleic acids that are stringent with the human homologs of the sgk gene family

Conditions can hybridize. The kit can also contain antibodies that are directed against the human homologs of the sgk protein family and nucleic acids that hybridize with the human homologues of the sgk gene family under stringent conditions. Particularly preferably, the kit according to the invention for diagnosing Long-Q / T syndrome can also be antibodies which are directed against the hsgkl protein, or

Contain nucleic acids that can hybridize with the hsgkl gene under stringent conditions. In this context, hybridization under stringent conditions is understood to mean hybridization under such hybridization conditions with regard to the hybridization temperature and formamide content of the hybridization solution as is described in the relevant specialist literature (Sambrook-J and Russell-DW (2001) Cold Spring Harbor, NY, CSHL Press) has been described.

In particular, the diagnostic kit can contain single or double-stranded nucleic acids as hybridization probes that have a sequence according to SEQ ID No. Have 1 or 2 which are at least 10 nucleotides / base pairs long and which comprise the polymorphism at position 732/733 in intron 2 of the hsgkl gene either with or without the insertion of the nucleotide G.

In the diagnostic kit according to the invention, in particular those antibodies are provided which are specifically directed against regions of the hsgkl protein whose presence in the hsgkl protein depends on the presence of the G insertion at position 732/733 in intron 2 of the hsgkl gene. In particular, regions which are alternatively spliced out in the immature mRNA due to the presence or absence of this G insertion and therefore are not present in the mature mRNA and in the protein resulting therefrom, are suitable as immunogenic epitopes against which diagnostic antibodies are directed can. Accordingly, nucleic acid regions of the hsgkl gene are also particularly suitable as diagnostic hybridization probes which can hybridize with such a gene region spliced out at position 732/733 depending on the G insertion.

The kit for diagnosing Long-Q / T syndrome can preferably also contain such nucleic acid fragments as specific hybridization probes that the known SNPs in the hsgkl gene, in particular the SNP in exon 8 (C2617T, D240D), the SNP in intron 6 (T2071C ) and / or the SNP in intron 2 at position 732/733 (insertion of G).

The correlation demonstrated in the context of the invention between the genetic makeup of the genes of the hsgkl gene family and the length of the Q / T time also enables a therapeutic use of functional activators or positive ones Transcription regulators of the sgk family for the treatment of Long-Q / T syndrome and similar diseases, which are also associated with an extended Q / T time. Here, a “functional activator” is to be understood as a substance that activates the physiological function of the corresponding kinase of the sgk family. A “positive transcription regulator” is to be understood as a substance that activates the expression of the corresponding kinase of the sgk family.

Another object of the invention thus relates to the use of a functional activator or a positive transcription regulator of a human homologue of the sgk family, in particular the hsgkl, for lowering the Q / T time and in particular for the therapy and / or prophylaxis of the Long-QT syndrome , Known functional activators and / or positive transcription regulators of the human human homologues of the sgk family, in particular the hsgkl, are glucocorticoids, mineral corticoids, aldosterone, gonadotropins, and a number of cytokines, in particular TGF-ß.

The invention therefore further relates to the use of substances selected from the group consisting of glucocorticoids, mineral corticoids, aldosterone, gonadotropins and cytokines, in particular TGF-β, for the manufacture of a medicament for the therapy and / or prophylaxis of Long-QT syndrome. The invention further relates to a medicament containing a substance selected from the group of substances mentioned above for the therapy and / or prophylaxis of the Long-Q / T syndrome.

The present invention is explained in detail by the following examples.

example 1

In the context of the present invention, a correlation study was carried out in which the genotype of the hsgkl gene of different patients (twins) was compared with the systolic and diastolic blood pressure values measured on them and statistically evaluated.

75 pairs of twins were used for correlation analysis (Busjahn et al., J Hypertens 1996, 14: 1195-1199; Busjahn et al, Hypertension 1997, 29:

165-170). The test subjects were all members of the German-Caucasian breed and came from different parts of Germany. Blood was taken from the twins and their parents for verification of the bipolar structure and for further molecular genetic analyzes. Each participating subject was previously examined by a doctor. No chronic medical illness was known to any of the test subjects. After 5 min, the blood pressure of the test person in the sitting position was measured by a trained doctor using a standardized mercury sphygmomanometer (2 measurements with a time interval of 1 min). The mean of the two measurements was used as the blood pressure value.

The advantage of dizygot twins for correlation studies is that they match in age and that the external influences on their phenotypes can be considered minimal (Martin et al., Nat Genet 1997, 17: 387-392).

The importance of twin studies in elucidating complex genetic diseases was recently described by Martin et al., 1997.

The twinnedness of the twin pairs was confirmed by the amplification of five microsatellite markers using the polymerase chain reaction (PCR). In this analysis of microsatellite markers, deoxyribonucleic acid (DNA) fragments are amplified by means of specific oligonucleotides by PCR, which contain highly variable regions in different human individuals. The high variability in these regions of the genome can be detected by slight differences in the size of the amplified fragments, as a result of which double bands, so-called microsatellite bands, form after diversity at the corresponding locus after gel-electrophoretic separation of the PCR products (Becker et al., J. Reproductive Med 1997, 42: 260-266).

For the molecular genetic analysis of the target gene, here the hsgkl gene, three further microsatellite marker regions (d6s472, d6sl038, d6s270) in the immediate vicinity of the hsgkl locus were amplified by PCR and then compared with the corresponding samples from the other twin and the parents , In this way it was possible to decide whether the twins had inherited identical or different alleles from their parents with regard to the allele examined. The correlation analysis was carried out using the so-called "structural equation modeling" (SEM) model (Eaves et al., Behav Genet 1996, 26: 519-525; Neale, 1997: Mx: Statistical modeling. Box 126 MCV, Richmond, VA 23298 : Department of Psychiatry. 4 ^Λ edition). This model is based on variance-covariance matrices of the test pairs by the probability of them either none, one or two identical alleles are characterized. The variance regarding the phenotype was divided into a variance based on the genetic background of all genes (A), a variance based on the genetic background of the target gene (Q), here the hsgkl gene, and the variance due to external influences (E ) is based.

VAR = A ² + Q ² + E ²

The covariance of a test pair was defined as follows for the three possible allele combinations IBDo, IBDi, IBD (IBD = "identical by descent"; 0, 1 or 2 identical alleles):

COV (IBD ₀ ) = 0.5 A ² COV (IBDι) = 0.5 A ² +0.5 Q ² COV (IBD ₂ ) = 0.5 A ² + Q ²

In order to estimate the correlation between the genetic makeup of the hsgkl locus and the subject's blood pressure, the differences between models that take the genetic variance with respect to the target gene hsgkl into account or not take it into account were calculated as χ ² statistics. The allele ratios for each pair and each locus were calculated using the so-called "multipoint" model (MAPMAKER / SIBS; Kruglyak et al., Am J Hum Genet 1995, 57: 439-454) based on the parental genotypes.

The greater significance of the analysis method, which is based on a variance-covariance estimate, in comparison to the χ ² statistics described above (SAGE Statistical Analysis for Genetic Epidemiology, Release 2.2. Computer program package, Department of Epidemiology and Biostatistics, Gase Western Reserve University, Cleveland, OH, USA, 1996) was recently confirmed in a simulation study (Fulker et al., Behav Gen 1996, 26: 527-532). An error probability p <0.01 was accepted in order to ensure a significant correlation with regard to the criteria of Lander and Kruglyak (Lander et al., Nat Genet 1995, 11: 241-246).

The results of this correlation study are shown in Table 1. Table 1:

As can be seen from Table 1, the low values for the error probabilities p determined, which do not or only slightly exceed the accepted error probability of p <0.01, prove the direct correlation between the genetic variance with regard to the hsgkl locus and the phenotypically determined variance the measured blood pressure.

Example 2

The genomic organization of the hsgk 1 gene has already been described (Waldegger et al, Genomics, 51,299 [1998]), http://www.ensembl.org/Ηomo_sapiens/geneview?gene= ENSG00000118515).

In order to identify SNPs whose occurrence is relevant for a predisposition to the development of hypertension, the SNPs in the hsgkl gene published in databases were first examined to determine whether they were real SNPs - and not pure sequencing errors - and whether the SNPs were sufficient are polymorphic to provide the basis for diagnostic evidence of a predisposition to hypertension. In this way, the SNP rs 1057293 was already in exon 8, which concerns an exchange of a C into a T, (http://www.ensembl.org/Homo_sapiens/snpview? Snp = l 057293; http: //www.ncbi . nlm.nih.gov/SNP/snp_ref. cgi? type = rs & rs = l 057293) and a second SNP, which is located in the hsgkl gene exactly 551 bp from the first SNP in the donor splice site of intron 6 to exon 7 and which concerns the exchange of a T into a C.

Example 3

Blood samples were taken from a sample of the 75 pairs of twins. After amplification of the genomic DNA of the hsgkl gene from the blood samples by means of PCR the exons and introns (but not the promoter region) of the hsgkl gene were sequenced directly and completely using suitable sequencing primers. In a sequence comparison of the hsgkl genes, which originated from different subjects, a further polymorphism in intron 2 was noticed, consisting of the insertion of an additional nucleotide G in position 732/733. The presence or absence of this G insertion at position 732/733 in the hsgkl genes of the individual test subjects also showed a significant correlation to the blood pressure measured in the individual test subjects: InsG / InsG genotypes showed significantly lower mean values systolic and diastolic blood pressure values as the rarer WT / WT genotypes and also as heterozygous WT / InsG genotypes (see Table 3). In contrast, other polymorphisms in the hsgkl gene showed a less significant correlation to the measured blood pressure (e.g. intron 6 (C2071T) and exon 8 (T2617C, D240D)) or no correlation to the measured blood pressure (e.g. intron 3 position Ins 13 + xT, T1300-1312 and Intron 4 (C 145 IT) and Intron 7 position 2544delA), as Table 2 shows.

The ECG measurement values also measured on the test subjects also showed a clear correlation of the Q / T times determined for the individual test subjects with the genotype of the test subjects with regard to the polymorphism in intron 2 at position 732/733 of the hsgkl gene: test subjects showed this the rarer WT / WT genotype significantly shorter Q / T times than heterozygous WT / InsG subjects and these in turn significantly shorter Q / T times than subjects with the more common InsG / InsG genotype (see Table 3). Longer Q / T times increase the risk of developing cardiac arrhythmias, in particular the Long Q / T syndrome. This leads to reverse correlations between the genotype of the polymorphism in intron 2 at position 732/733 of the hsgkl gene with a predisposition for Long-Q / T syndrome on the one hand and with a predisposition for hypertension on the other hand. These correlations can be used for the diagnosis, therapy and prophylaxis of hypertension and Long-Q / T syndrome.

Table 2:

Intron 2 Intron 3 Intron 4 Intron 6 Intron7 Exon 8

SNP /

Position Position C1451T C2071T Position delA T2617C, DNA No. InsG lns13 + xT 2544delA D240D

Table 3:

Claims

claims

1. Use of an isolated single- or double-stranded nucleic acid containing a fragment of the nucleic acid sequence according to SEQ ID No. 1 or according to SEQ ID No. 2 for the diagnosis of hypertension, characterized in that said fragment is at least 10 nucleotides / base pairs long and that said fragment comprises the polymorphism in intron 2 of the hsgkl gene either with or without the insertion of nucleotide G at position 732/733.

2. Kit for the quantitative diagnosis of hypertension, comprising at least one isolated single- or double-stranded nucleic acid as defined in claim 1.

3. Kit for the quantitative diagnosis of hypertension, containing at least one antibody against a region of the hsgk protein, characterized in that the presence of said region in the hsgkl protein from the presence of an insertion of

Nucleotide G at position 732/733 in intron 2 of the coding hsgk gene is dependent.

4. A method for diagnosing hypertension comprising the following process steps: a) taking a body sample, b) optionally isolating and / or amplifying genomic DNA, cDNA or mRNA from the body sample after a), c) quantifying the alleles that are required to insert the Have nucleotides G at position 732/733 in intron 2 of the hsgkl gene.

5. The method according to claim 4, characterized in that the body sample from step a) is selected from the group consisting of blood, saliva, tissue, cells.

Method according to Claim 4 or 5, characterized in that the alleles are quantified after step c) by direct sequencing of the genomic DNA or the cDNA which has been isolated from the body sample.

7. The method according to claim 4 to 6, characterized in that the quantification of the alleles after step c) by specific hybridization of the genomic DNA or the cDNA, which was isolated from the body sample, takes place.

8. The method according to claim 4 to 7, characterized in that the quantification of the alleles after step c) is carried out by a PCR-oligo elongation assay or a ligation assay.

9. Using the direct correlation between the overexpression or the functional molecular modification of human homologs of the sgk family and the length of the Q / T time to diagnose the Long-QT syndrome.

10. Use of the single- or double-stranded nucleic acid comprising the sequence of a human homologue of the sgk family or one of its fragments with a length of at least 10 nucleotides / base pairs for the diagnosis of

Long QT syndromes.

11. Use according to claim 9 or 10, characterized in that the human homologue of the sgk family is the hsgkl gene.

12. Use according to claim 11, characterized in that the nucleic acid of the hsgkl gene or one of its fragments has a length of at least 10 nucleotides / base pairs and that said nucleic acid either has the polymorphism at position 732/733 in intron 2 of the hsgkl gene or without the insertion of nucleotide G.

13. Use of an antibody against a substrate of a human homologue of the sgk family for the diagnosis of a predisposition to the development of Long-Q / T syndrome, the antibody being directed against such an epitope of the human homologue which the phosphorylation site either in phosphorylated form or contains in non-phosphorylated form.

14. Use according to claim 13, characterized in that the substrate of the human homologue of the sgk family Nedd4-2 with the Acc No. BAA23711 is.

15. Kit for the diagnosis of Long-QT syndrome, containing antibodies which are directed against the human homologues of the sgk protein family or nucleic acids which can hybridize with the human homologues of the sgk gene family under stringent conditions, or these antibodies and nucleic acids together.

16. Kit according to claim 15, characterized in that the human homologue of the sgk family is the hsgkl gene.

17. Use of a functional activator or positive transcription regulator of a human homologue of the sgk family, in particular the hsgkl, to lower the Q / T time.

18. Use according to claim 17, characterized in that the functional activator or positive transcription regulator is selected from the group consisting of glucocorticoids, marcorticoids, aldosterone, gonadotropins and cytokines, in particular TGF-ß.

19. Use of substances selected from the group consisting of glucocorticoids, mmeralcorticoids, aldosterone, gonadotropins and cytokines, in particular TGF-β, for the manufacture of a medicament for the therapy and / or prophylaxis of the Long-QT syndrome.

20. Medicament containing at least one substance from the group of substances consisting of glucocorticoids, marcorticoids, aldosterone, gonadotropins and cytokines, in particular TGF-ß, for the therapy and / or prophylaxis of the Long-QT syndrome.