DK178879B1 - Method of diagnosing asthma and other wheezing disorders. - Google Patents

Abstract

There is a need for a method of determining whether an individual has or is at risk for developing asthma or other wheezing disorder by identifying a specific disease mechanism that can potentially be treated. The present invention fulfills such a need by providing: - a method of testing a subject thought to have or be predisposed to having asthma or other wheezing disorder by detecting CDHR3 gene variants consisting of at least one of the single nucleotide polymorphisms (SNPs) rs6959608, rs10488047 and rs6967330.

Description

Description

Field of the invention

The present invention relates to a method of diagnosing a subject thought to have or be predisposed to asthma or other wheezing disorders by detecting CDHR3 gene variants consisting of at least one of the single nucleotide polymorphisms (SNPs) rs6959608, rsl0488047 and rs6967330.

Background of the invention

Asthma is the main cause for health care utilization in childhood (1-5). In particular, acute exacerbations are a significant part of the disease burden due to the associated risk of patient suffering and anxiety, complications, acute hospitalization, and the significant health care resources consumed. It is a main goal in international guidelines of asthma management to avoid exacerbations (6;7). Still, exacerbations are less well controlled than the daily asthma symptoms, and surveys from the U.S. and Europe consistently report that 20-40% of children with a recognized asthma diagnosis require acute medical care yearly. This is a reflection of the inadequacy of the available treatment options for prevention and treatment of acute asthma exacerbations (8), suggesting that asthma with severe exacerbations may represent a distinct subtype of disease and demonstrating a need for improved understanding of its pathogenesis to develop individualized treatment for this particular endotype.

Asthma heritability is estimated to 70-90% (9; 10). A large number of candidate genes have been suggested and a smaller number have been confirmed in genome-wide association studies (GWAS) (11-16), but still the genetic background of asthma remains poorly understood.

Because asthma can become progressively more severe over time, it is important to determine individuals that are susceptible to the disease at a young age and preferably prevent disease. Thus, what is needed in the art is a mechanism for determining whether an individual is at risk for asthma by a specific mechanism that can potentially be treated. The present invention fulfills such a need.

Brief description of the figures FIG 1A. CDHR protein expression in experimental models of the CDHR3 gene variant (C529Y / rs6967330). Plasmids encoding wild-type and C529Y mutant CDHR3, as well as empty pBabe+CMV-Puro as a control, were transiently transfected into 293T cells. Cells were analyzed 48 hours after transfection. Data are representative of 3 independent experiments (transfections). Transfected 293T cells were stained for Flag expression at the cell surface, followed by PE-conjugated goat-anti-mouse secondary antibody. Cells were fixed, permeabilized, and stained again with the anti-Flag antibody, followed by Alexa-647-conjugated goat-anti-mouse secondary antibody. Data were acquired by flow cytometry and gated by FSC and SSC for intact-cell-sized events. Data presented represent the surface and intracellular staining observed in gated events. The percentages shown in the top two quadrants represent the percent of gated events that are positive for intracellular staining but negative for surface staining (upper left quadrant) and the percentage of gated events positive for both intracellular and surface expression (upper right quadrant). FIG IB. Transfected cells were lysed, and whole cell lysates were separated by SDS-PAGE under reducing or non-reducing conditions. Proteins were transferred to PVDF, and western blotted for Flag. FIG 2. Representative images of HEK293T-cells transfected with either C529Y-mutant or WT-plasmid. Cells were immunostained for extracellular CDHR3 (green), then fixed and afterwards permeabilized and immunostained again, this time for intracellular CDFIR3 (red). Nuclei were stained with DAPI (4',6-diamidino-2-phenylindole) (blue).

Detailed description of the invention

The present invention is based on the discovery by the present inventors that gene-variants in the CDHR3-gene are associated with increased risk of asthma in young children.

Thus, the present invention provides a method of testing a subject thought to have or to be at risk of developing asthma and other wheezing disorders which comprises the step of analyzing a biological sample from said subject for detecting the presence of at least one of the single nucleotide polymorphism (SNPs) rs6959608, rsl0488047 and rs6967330 variants in the CDHR3 gene.

Said method is useful for testing a subject thought to have or be predisposed to having asthma. Said method, by detecting the presence of one of the above mentioned gene variants in a subject, permits to confirm that said subject has or is predisposed for having asthma.

As used herein, the term "subject" refers to a mammal, preferably a human. As used herein, the expression "biological sample" refers to solid tissues such as, for example, a lung biopsy; buccal swab, fluids and excretions such as for example, sputum, induced sputum, blood, serum, plasma, urine. Preferably, said biological sample is a fluid sample and most preferably a blood sample. The sequences of the CDHR3 gene are well known by one skilled in the art and include the gene CDHR3 for Homo sapiens. The skilled man will immediately appreciate that the information presented herein relating to the human CDHR3 gene may easily be equated or correlated with a similar mutation at a corresponding location for the CDHR3 gene from another species.

Typical techniques for detecting the mutation may include restriction fragment length polymorphism, hybridisation techniques, DNA sequencing, exonuclease resistance, microsequencing, solid phase extension using ddNTPs, extension in solution using ddNTPs, oligonucleotide ligation assays, methods for detecting single nucleotide polymorphisms such as dynamic allele-specific hybridisation, ligation chain reaction, minisequencing, DNA"chips", allele-specific oligonucleotide hybridization with single or dual-labeled probes merged with PCR or with molecular beacons, and others.

Preferably, said technique for detecting a mutation is selected in the group comprising methods for detecting single nucleotide polymorphisms.

In the following, the invention is described in more detail with reference to amino acid sequences, nucleic acid sequences and expression of CDHR3.

Methods

The COPSACexacerbation cohort is a register-based cohort of children with asthma who were identified and characterized from national health registries. The study was approved by the Ethics Committee for Copenhagen (H-B-2998-103) and The Danish Data Protection Agency (2008-41-2622).

Case selection: Children with repeated acute hospitalizations (cases) were identified in the Danish National Patient Register (DNPR) covering all discharge diagnoses from Danish hospitals since 1977.(17) Information on birth-related events was obtained from the national birth register. Inclusion criteria were at least 2 acute hospitalizations for asthma (ICD8-codes 493, ICD-10 codes J45-46) from 2 to 6 years of age (both years in inclusive). Duration of hospitalization had to be more than 1 day, and 2 hospitalizations had to be separated by at least 6 months. Exclusion criteria were competing side-diagnosis during hospitalization, any registered chronic diagnosis considered to affect risk of asthma hospitalization, low birth weight (<2500 g), or gestational age below 36 weeks. Cases were characterized with respect to frequency of atopy and symptom burden of hospitalization from asthma, acute bronchitis and lower respiratory tract infections from DNPR. DNA-sampling and genotyping of cases: DNA was obtained from blood spots sampled as part of the neonatal screening program and stored in the Danish Newborn Screening Biobank since 1982.(18) Two disks, each 3.2mm in diameter, were punched from each blood spot. DNA was extracted using the Extract-N-Amp kit (Sigma-Aldrich). Each individual sample was whole-genome amplified in triplicates using the REPLIg kit (QIAGEN) as previously described.(19) The three amplifications were pooled and the concentration of whole-genome amplified DNA (wgaDNA) was determined by Quant-IT PicoGreen dsDNA Reagent (Invitrogen). Prior to SNP genotyping, the samples were normalized to 50 ng/μΙ . Cases were genotyped on the Affymetrix Axiom CEU array (567,090 SNPs). Two SNPs in linkage disequilibrium with the CDHR3 top-SNP were individually genotyped at KBioscience®.

Controls: The control population consisted of adults from Denmark, who had previously been whole genome genotyped as participants in the Genetics of Overweight Young Adults (GOYA) study.(20) The control samples used here were randomly drawn from two large Danish cohorts: the Danish National Birth Cohort (females) and the Copenhagen draft board examinations (males). Individuals who indicated in a questionnaire to have physician-diagnosed asthma were excluded. Controls were genotyped on the lllumina Human610-Quad vl.O BeadChip (545,350 SNPs) at the Centre National de Génotypage (CNG), Evry, France.

The COPSAC;nnn Cohort

Replication of novel risk-loci was sought in the Copenhagen Prospective Study on Asthma in Childhood (COPSAC)2ooo cohort, a prospective clinical study of a birth-cohort of 411 children. All mothers had a history of doctor's diagnosis of asthma after age 7. The newborns were enrolled in the first month of life as previously described in detail.(21-24). The study was approved by the Ethics Committee for Copenhagen (KF 01-289/96) and The Danish Data Protection Agency (2008-41-1754). Written informed consent was obtained from both parents. The cohort is characterized by deep phenotyping during close clinical followup; participants were assessed at six-monthly intervals at the COPSAC clinical research unit and additional visits were arranged immediately upon the onset of respiratory symptoms, the doctors employed at the clinical research unit were acting primary physician for the children of the cohort for diagnosis and treatment of any respiratory symptoms, and asthmatic symptoms were recorded in daily diaries.(24)

Statistical analyses

Genome Wide association analysis: Quality control was carried out separately on cases and controls. This included filtering on SNP call rate (>99%) and sample call rate (>98%) and tests for excess heterozygosity, deviation from Hardy-Weinberg equilibrium, gender mismatch and familial relatedness. Non-Caucasian individuals were excluded based on deviation from the HapMap CEU reference panel (release 22). Indication of population stratification or genotyping bias was tested for by principal component analyses after quality control. The merged data of SNPs present on both arrays after quality control was used for association testing in PLINK (Purcell, S. et al. PUNK, Purcell, S. Package: PLINK 1.07.) using a logistic additive model. COPSAC2QOO:

Cumulative risk of age at onset of exacerbations, asthma and eczema was estimated using Kaplan-Meier estimates and comparisons were made by log rank tests. The effect was quantified in terms of hazard ratios by Cox proportional hazards regression (p-values correspond to Wald-tests). All analyses were done using SAS version 9.2(SAS Institute Inc, Cary, NC) and the open source statistical programming environment R version 2.11.0 (www.r-project.org).

Functional studies of the CDHR3 variant CDHR protein expression in experimental models of the CDHR3 gene variant fC529Y/rs69673301 CDHR3 constructs and mutagenesis: A plasmid containing the coding sequence of human CDHR3 in the pCR-Bluntll-Topo backbone was acquired from Open Biosystems (Thermo Scientific, Lafayette CO). Quikchange Lightning mutagenesis (Agilent Technlogies, Clara CA) was used to insert a Flag tag into the CDHR3 coding sequence, between the predicted signal sequence and the predicted beginning of the mature polypeptide (between the 19th and 20th amino acid of the complete protein). The primers used for the mutagenesis were: Forward -atgtcagggggagaagcaGATTACAAGGATGACGACGATAAGACCGGTctacacctaatcctctta and Reverse -taagaggattaggtgtagACCGGTCTTATCGTCGTCATCCTTGTAATCtgcttctccccctgacat. The proper insertion of the Flag tag was confirmed by Sanger sequencing. The C529Y mutation was generated by a second round of Quikchange Lightning mutagenesis, using the following primers: Forward - gctggtaactaaagtCgactAtgaaacaacccccatctata and Reverse - tatagatgggggttgtttcaTagtcGactttagttaccagc. These primers contained the point mutation required to mutate cysteine-529 to tyrosine, as well as a second, silent point mutation that served to introduce a Sail site for screening purposes. The introduction of the mutations and the integrity of the entire CDHR3 sequence were confirmed by Sanger sequencing. Finally, the Flag-tagged wild type and C529Y mutant CDHR3 sequences were amplified by PCR and subcloned into the pBabe+CMV-Puro vector. The PCR primers used for this amplification were: Forward -GATCCTCGAGGCCACCatgcaggaagcaatcattctcctgg and Reverse - GATCGCGGCCGCttactttcctgggtgtggtttggg. CDHR3 expression, flow cytometry, and western blotting.

Plasmids encoding wild type or mutant CDHR3, or the empty pBabe+CMV-Puro vector, were transfected into 293T cells by Fugene6 transfection (Promega, Madison Wl). The 293T cells were from the American Tissue Culture Center (ATCC, catalog number: CRL-3216). They were recently tested for mycoplasma contamination, but were not authenticated. 48 hours after transfection, cells were removed from their plates with 3 mM EDTA in PBS. Cells were washed with PBS, and resuspended in PBS + 0.5% BSA + 1 mM sodium azide (PBA buffer). Cells were stained for surface Flag expression with anti-Flag antibody (clone M2, Agilent, 2 pg/ml), washed twice with PBA buffer, and stained with PE-conjugated goat-anti-mouse secondary antibody (BD Biosciences, Sparks MD, 2 μg/ml). Cells were washed in PBS, fixed in 2% paraformaldehyde, and permeabilized in PBA buffer + 0.5% saponin. Permeabilized cells were stained again for Flag (2 pg/ml), washed with PBA + saponin, stained with Alexa-Fluor-647 conjugated goat-anti-mouse secondary antibody (Invitrogen, Grand Island NY, 20 μg/ml), and washed with PBA + saponin. Cells were resuspended in PBS, and flow cytometry was performed using the Accuri C6 instrument (Accuri, Ann Arbor Ml). Data were analyzed in FlowJo (Tree Star, Ashland OR). For western blot, cells expressing CDHR3 proteins were lysed in PBS + 0.5% Triton X100 supplemented with complete protease inhibitor tablets (Roche, Madison Wl). Whole cell lysates were separated by SDS-PAGE, under reducing or non-reducing conditions, transferred to PVDF membranes, and blotted for Flag (M2). Three independent tranfections of the CDHR3 cDNAs were performed on three different days. Each experiment was processed as described. Each experiment consisted of 1 well of 293T cells transfected with the following plasmids: Empty Vector Control, CDHR3 Wild Type in pBabe, or CDHR3 C529Y in pBabe.

Immunoflourescence and confocal microscopy. 293T cells were grown on glass coverslips with DMEM (Dulbecco's modified Eagle's medium), 3 mM glutamine, 10% heat-inactivated fetal bovine serum (FBS) at 37°C, 5% C02 prior to and for 2 days posttransfection with expression constructs for FLAG-tagged CDHR3 wildtype and CDHR3 C529Y variant using TransIT 2020 reagent using standard protocol (Mirus Bio LLC). Cells were washed and stained with primary anti-FLAG mouse antibodies, incubated for 1 hour at 37° C and washed again with PBS. Then the cells were stained with secondary rabbit anti-mouse antibodies conjugated with fluorescienisothiocyanate (FITC) and incubated at 37°C for 30 minutes, then washed with PBS. Afterwards cells were fixed 2% paraformaldehyde for 15 minute, washed with PBS and permeabilized in 0.2% Triton X-100 in PBS for 5 minutes, washed and then incubated with Cy3 conjugated mouse anti-FLAG antibody. Finally cells were mounted with ProLong Gold antifade reagent with DAPI (Invitrogen). Images were acquired using a Leica DMI 6000-B confocal microscope (Leica Microsystems, Wetzlar DE) with 40X magnification and processed in Photoshop (Adobe

Systems). The experiments were performed in triplicates (three independent transfections) on three different days.

Functional consequence of the CDHR3 gene variant frs6967330) on protein expression Staining transfected cells for cell surface expression of the Flag-tagged CDHR3 proteins revealed that the wild-type protein was expressed very poorly at the cell surface, while the C529Y variant showed better cell surface expression (FIG 1A). For flow cytometry, three independent transfections of the CDHR3 cDNAs were performed on three different days. Each experiment was processed as described in the methods. The percentage of cells that showed cell surface staining was consistently higher with the mutant than with the wild type variant (at least three times higher), even when the mutant was less well transfected (as shown by the intracellular staining). We chose one of the three experiments as representative, and used that to make the figure represented in FIG 1A.

Intracellular staining of the transfected cells demonstrated that wild-type and C529Y CDHR3 were expressed equally well, despite the differences in cell surface expression. Western blot analysis of lysates of transfected cells revealed a single band when gels were run under reducing conditions (FIG IB). Running lysates under non-reducing conditions results in the appearance of two bands of higher molecular weight, which are likely disulfide bonded complexes of the CDHR3 molecules with other cellular proteins. However, there were no noticeable differences between the wild-type and C529Y proteins, indicating that the introduced mutations did not result in differences in disulfide bond formation that could be revealed by western blot.

Three additional experiments were performed for immunofluorescence staining. The results of 3 individual experiments consistently showed surface expression in the risk variant only. Data (FIG 2) are representative of 3 individual experiments.

Results

Case criteria were fulfilled for 2,029 out of 1.7 million children born between 1982 and 1995 (1.1/1000 children). The final COPSACexacerbation cohort after applying exclusion criteria, DNA-isolation, genotyping and statistical quality control comprised 1178 children with repeated hospitalization for asthma. The average number of acute hospitalization from asthma or acute bronchitis was 4 (IQR 3-6), and 39% had their first hospitalization before two years of age. 58% had a concurrent atopic diagnosis . Compared to the general population, cases were more often boys (67 vs. 51 %) and more often had mothers who smoked during pregnancy (32 vs. 15 %). 2522 controls were available for genome-wide analysis, and the number of available markers on both case and control platform was 136,792 SNPs. Principal component analysis after quality control showed no evidence of population stratification.

The genome-wide association analysis detected an excess of association signals beyond those expected by chance and SNPs from 7 regions reached genome-wide significance (P< 5 x 10-8). Top SNPs from the 7 loci were: rs2305480 on chromosome 17 near GSDMB (OR = 0.43, P = 2.0 x 10"51), rs928413 on chromosome 9 near IL-33 (OR = 1.5, P = 1.4 x 1013), rsl794275 on chromosome 6 near HLA-DQB (OR = 0.61, P = 1.4 x 10 10), rs6871536 on chromosome 5 near RAD50/IL-13 (OR = 1.45, P = 8.6 x 10"10), rsl558641 on chromosome 2 near IL1RL1 (OR = 0.64, P = 4.9 x 10"9), and rs6967330 on chromosome 7 in CDHR3 (OR = 1.45, P = 1.1 x 10 s) (Table 1).

Replication was sought in the childhood onset stratum from a previously published large scale GWAS on asthma. 6 of the 7 SNPs showed significant replication after conservative Bonferroni adjustment for multiple testing, and with the same direction of effect (Table 1).

Gene variant information on SNPs in CDHR3 associated with exacerbations were:

Marker name rs6967330, position 105445687on chromosome 7, risk allele A, OR=1.45, P-value = 1.1 x 10"8 Marker name rs6959608, position 105463850 on chromosome 7, risk allele G, OR=1.43, P-value = 4.5 x 10"7 Marker name rsl0488047, position 105452573 on chromosome 7, risk allele T, OR=1.36, P-value = 4.8 x 10'5 The CDHR3-locus has not previously been associated with asthma or any other atopic trait and was followed up in further analyses.

Replication and sub-phenotyping of CDHR3 effects in COPSAC?nnn

The rs6967330 risk variant (A) was associated with increased risk of acute severe exacerbations (HR 1.9, [1.1-3.2], P=0.02) and asthma (HR 1.7 [1.1-2.9], p=0.02) from 0-7 years of life.

Support for the causal genetic variant within the CDHR3 locus and elucidating the related genetic mechanism

The potential functional consequences of the CDHR3 top variant (rs6967330/C529Y) were investigated by generating expression constructs in which the human CDHR3 sequence was tagged, and the C529Y mutation was introduced by site-directed mutagenesis into 293T cells. Consistent results from six independent experiments, three involving flow cytometry (FIG 1A) and three involving immunofluorescence staining (FIG 2), revealed that the wild-type protein was expressed at very low level at the cell surface, while the C529Y variant showed marked enhancement in cell surface expression of the protein.

Table 1. Discovery and replication results for the genome wide significant loci in the discovery analyses. Replication results are from a previously published large-scale genome wide association study of asthma {childhood onset subanalysis). Moffat MF, Gut IG, Demenais F, et al. A large-scale consortium-based genomewide association study of asthma. N Engl J Med 2010;125:328-35.

Discussion

Summary of findings

We performed the first well-powered genome-wide association study of acute severe exacerbations in early childhood and identified 6 susceptibility loci, including one new asthma gene, CDHR3. The CDHR3-asthma association was robustly replicated in a large asthma study and further by phenotype-specific replication in a well-characterized birth cohort study. The expression pattern and putative function of CDHR3 suggests airway epithelial barrier as an important future research focus.

Strength and Limitations

The method of case identification through national health registries combined with DNA from a national biobank allowed us to define the highly specific phenotypes of COPSACexacerbations including only young children with repeated acute hospitalizations from 2 to 6 years of age. The specificity of asthma diagnoses in the Danish Hospital Discharge Register was previously found to be high in older children (0.90).(25) Case specificity was further assured from a minimum duration of hospitalization of more than 24 hours, a minimum interval between hospitalizations of 6 months, and exclusion of individuals diagnosed with other chronic diseases or competing diagnoses during hospitalization. This population will to a certain extent include uncontrolled asthma not necessarily due to severity but also due to poor compliance, and cases of asthma debut. Still, the strong results for known asthma genes validate the phenotype specificity of the cohort.

Results were replicated in a large independent study on asthma and further in a second independent birth cohort study making the risk of a chance finding very unlikely. The detailed phenotype associated with CDHR3 gene variants, including symptom history and lung function from birth, was described in the extensively characterized COPSAC2ooo birth cohort.

Interpretation

Cadherin-related family member 3 (CDHR3) has not previously been associated with asthma or any other human disease. The biological function of CDHR3 in humans is unknown, but it belongs to the cadherin gene family of transmembrane proteins involved in homologous cell-adhesion of importance for epithelial polarity, cell-cell interaction, and differentiation (26). Other members of the cadherin family have been associated with asthma and asthma-related traits, including E-cadherin (27) and protocadherin (28). CDHR3 was found to be differentially overexpressed in lungs in a study with normal human tissues (29), overexpressed in bronchus, trachea and lungs in an independent study of human post mortem tissue samples (30), and highly expressed in the developing human lung (31). Protein expression has been demonstrated in respiratory epithelial cells of the nasopharynx (Human Protein Atlas).

The associated SNP at this locus (rs6967330) is a non-synonomous coding SNP within the CDHR3-gene.

Two SNPs with partial LD were modestly associated with asthma both in the present and the GABRIEL study. It remains a possibility that rs6967330 is not the causal variant but is tagging a causal variant not represented in these two studies.

The CDHR3 protein consists of a large extracellular part (residues 1-724) consisting of six cadherin domains followed by a single transmembrane segment and a smaller intracellular domain (residues 746-906). The risk-associated SNP (rs6967330) is located in the fifth cadherin domain (counted from the membrane-distal end), where the risk allele causes an amino-acid change from cysteine to tyrosine in position 529. Protein structure modeling based on the structure of mouse N-cadherin (PDB-id 3Q2W) shows that Cys529 is located at the interface between the two membrane-proximal cadherin domains, cdh5 and cdh6. Interestingly, Cys592 and Cys566, which are expected to form a disulfide bridge within cdh6, are close to Cys529 in cdh5 and the short distance could allow interactions with the potential for disulfide rearrangement. Overall, the localization at the domain interface suggests that the mutation of Cys529 to a tyrosine residue interferes with inter-domain stabilization, overall protein stability or conformation, all of which may affect cell adhesion properties.

Epithelial barrier defects are suspected to be pivotal in the asthma pathogenesis (32). The airway epithelium forms a physical barrier against environmental agents including microbial pathogens, allergens and pollutants. Structural abnormalities of the epithelium may increase the susceptibility to environmental stimuli by exaggerating immune responses and structural changes in underlying tissues, and increasing airway reactivity. Epithelial integrity is dependent on interaction of proteins in cell-cell junctional complexes, including adhesion molecules. Studies have shown impaired tight junction function (33) and reduced E-cadherin expression (34) in the airway epithelium of individuals with asthma. CDHR3 is a plausible disease related protein for asthma due to its localization in the airway epithelium and the known role of cadherins for cell-adhesion. We hypothesize that CDHR3 plays a role for cell adhesion in airway epithelium. The risk variant may decrease the adhesion properties of CDHR3 and thereby impair airway epithelial integrity and increase susceptibility to environmental stimuli leading to the pathological features of bronchial inflammation and hyper-reactivity characterizing asthma exacerbations. The majority of asthma exacerbations in children are caused by respiratory infections, predominantly common viral infections such as rhinovirus, but also bacterial infection has been suggested to play a role. It could therefore be speculated that CDHR3 gene variants increase the susceptibility to airway inflammation following respiratory infections. A similar role has been suggested for protocadherin 1 gene variants. CDHR3 may also play a role in epithelial differentiation and cell-cell interaction between immune cells in the airways. This finding stresses the importance of the airway epithelium in asthma pathogenesis.

Conclusion

We identified CDHR3 as a new susceptibility locus for early asthma with repeated severe exacerbations. The evidence for this locus is strong with genome wide significant association in the discovery analysis, robust replication in 2 independent studies, a biological plausible candidate gene involved in cell-adhesion, relevant organ expression (predominantly bronchial epithelium), and a coding variant with probable effect on protein structure and surface expression of CDHR3 protein. This supports the emerging hypothesis of the airway epithelium as an important determinant of asthma and asthma exacerbations. Targeting CDHR3 gene variants/dysfunction in individuals with asthma or at risk of asthma may improve diagnostics, prevention and/or treatment of asthma.

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Claims (1)

1) A method for diagnosing asthma and other asthmatic disorders in an individual suspected of or at risk of developing the diseases characterized by detection of CDHR3 gene variants consisting of at least one of the following single nucleotide polymorphisms (SNPs): rs6959608, rsl0488047 and rs6967330 .