Signal transducer and activator of transcription 6 haplotypes and asthma in the Indian population

A review on aero-allergen induced allergy in India

Allergic diseases such as bronchial asthma, rhinitis and eczema are an important public health issue globally in 21st century. Their prevalence and impact in India is high, in terms of total numbers of people affected. Due to diverse climate and lifestyle, the Indian population is exposed to a rich and varied range of aerobiological particles. In the last two decades in India, 83 pollens, 34 fungi, six dust mite and 19 insect species were reported as allergenic, often contributing to heavy allergenic exposure in indoor and outdoor environments. There are currently few practitioners who offer allergy diagnosis and treatment in India, but there is active basic and molecular research aiming to improve the health of allergic patients. This review explores the field of aero-allergy in India during the last two decades, with special emphasis on prevalence across various centres and relevant scientific advances such as genetic associations and new therapeutics. This review will be helpful for clinicians to select aero-allergens for sensitisation testing in patients suffering from symptoms in different regions of India, and to support patients undertaking prophylaxis of allergic symptoms in India according to local environmental conditions. This study also helps to define patient selection for allergy testing and the role of test results in guiding allergic disease management in the Indian context. Finally, we summarize genetic findings relevant to aero-allergy in India and discuss the development of novel therapeutics for investigation and management of aero-allergy in India.

Wheezing and itching: The requirement for STAT proteins in allergic inflammation

The development of allergic inflammation requires the orchestration of gene expression from the inflamed tissue and from the infiltrating immune cells. Since many of the cytokines that promote allergic inflammation signal through hematopoietin family receptors, the Signal Transducer and Activator of Transcription (STAT) family have obligate roles in pro-allergic cytokine-induced gene regulation in multiple cell types. In this review, we summarize work defining the contribution of each of the STAT family members to the development of allergic inflammation, using data from mouse models of allergic inflammation, studies on patient samples and correlations with single nucleotide polymorphisms in STAT genes.

Association of STAT6 variants with asthma risk: a systematic review and meta-analysis

A large number of studies have reported that the genetic variants in STAT6 gene may be implicated in susceptibility to asthma, but with inconsistent results. Therefore, the aim of this meta-analysis was to determine the likelihood of developing asthma for the individuals with different STAT6 variants. The database including Pubmed, Embase and CNKI (Chinese National Knowledge Infrastructure) were searched to find the relevant papers. Data were extracted by two independent reviewers and the odds radios (ORs) were pooled with 95% confidence intervals (CIs), using random effect or fixed effect models as appropriate, to indicate the risk of asthma for different STAT6 variants. The heterogeneity and bias were tested for each pooled result. Data from 19 studies were pooled that reported associations of rs324015, rs71802646 and rs324011 in STAT6 gene with asthma risk. The results demonstrated that 13GT and short GT in rs71802646 were both associated with increased risk of asthma in overall analysis (OR = 1.26 for 13GT and 1.30 for short GT). Further, subgroup analysis showed an increased risk of asthma in Asian population with 13GT (OR = 1.21), 14GT (OR = 1.97) and short GT (OR = 1.27). Besides, 13GT, 14GT and short GT all contributed to higher risk of atopic asthma, with OR 1.50, 2.21 and 1.65 respectively. However, rs324015 (G>A) appeared to be associated with decreased risk for atopic asthma (with OR = 0.83, 0.68 and 0.79 for A, AA and AA+AG respectively). Both overall and subgroup analyses indicated no effect of rs324011 on asthma risk. In conclusion, our meta-analyses suggest that short GT repeats of rs71802646 in STAT6 contribute to higher risk for asthma, while rs324015 may have a protective effect on atopic asthma.

PARP-14 binds specific DNA sequences to promote Th2 cell gene expression

PARP-14, a member of the poly ADP-ribose polymerase super family, promotes T helper cell 2 (Th2) differentiation by regulating interleukin-4 (IL-4) and STAT6-dependent transcription. Yet, whether PARP-14 globally impacts gene regulation has not been determined. In this report, using an RNA pol II ChIP-seq approach, we identify genes in Th2 cells that are regulated by PARP-14, and either dependent or independent of ADP-ribosyltransferase catalytic activity. Our data demonstrate that PARP-14 enhances the expression of Th2 genes as it represses the expression of Th1-associated genes. Among the relevant targets are Signal Transducer and Activator of Transcription genes required for polarizing Th1 and Th2 cells. To define a mechanism for PARP-14 function, we use an informatics approach to identify putative PARP-14 DNA binding sites. Two putative PARP-14 binding motifs are identified in multiple Th2 cytokine genes, and we demonstrate that PARP-14 interacts with each motif using in vitro binding assays. Taken together our results indicate that PARP-14 is an important factor for T helper cell differentiation and it binds to specific DNA sequences to mediate its function.

STAT6 - polymorphisms, haplotypes and epistasis in relation to atopy and asthma

BACKGROUND

STAT6 has an important role in the IL-4 / IL-13 signalling pathway. Genome - wide association studies have shown that particular polymorphism (SNP) or haplotype variants of STAT6 as well as epigenetic gene modifications are associated with IgE level and asthma in childhood.

METHODS

A review of the available literature was performed to map out the function and signalling pathway of STAT6, studies of STAT6 SNPs association with susceptibility to asthma and atopy, covering the years 1997 - 2012 were summarized, and the value of epigenetic and epistatic influences on STAT6 and their relevance to the development of the studied phenotype (atopy or asthma) were determined.

RESULTS

There are 2 SNPs (rs71802646 and rs320411) with clinical association and proven functional effect on STAT6 expression. The effect of STAT6 SNPs cumulates in haplotypes and more potently during interaction with SNPs in the genes from the signalling pathway (IL4, IL4Ra, and IL13). Expression of STAT6 is also influenced by DNA methylation. Atopy is traditionally believed to be maternally inherited but there is one report about paternally overtransmitted STAT6 haplotype (TCA haplotype, built from rs324011, rs3024974 and rs4559 SNPs).

CONCLUSIONS

STAT6 polymorphisms and their combinations have an important influence on IgE level and development of asthma. However, the interaction between SNPs in the IL-4 / IL-13 signalling pathway is of greater impact. Hypermethylation of the STAT6 promoter is also significant in the regulation of STAT6 expression and this fact opens possibilities for targeting therapy in asthma.

Pneumocystis elicits a STAT6-dependent, strain-specific innate immune response and airway hyperresponsiveness

It is widely held that exposure to pathogens such as fungi can be an agent of comorbidity, such as exacerbation of asthma or chronic obstructive pulmonary disease. Although many studies have examined allergic responses to fungi and their effects on pulmonary function, the possible pathologic implications of the early innate responses to fungal pathogens have not been explored. We examined early responses to the atypical fungus Pneumocystis in two common strains of mice in terms of overall immunological response and related pathology, such as cell damage and airway hyperresponsiveness (AHR). We found a strong strain-specific response in BALB/c mice that included recruitment of neutrophils, NK, NKT, and CD4 T cells. This response was accompanied by elevated indicators of lung damage (bronchoalveolar lavage fluid albumin and LDH) and profound AHR. This early response was absent in C57BL/6 mice, although both strains exhibited a later response associated with the clearance of Pneumocystis. We found that this AHR could not be attributed exclusively to the presence of recruited neutrophils, NKT, NK, or CD4 cells or to the actions of IFN-γ or IL-4. However, in the absence of STAT6 signaling, AHR and inflammatory cell recruitment were virtually absent. Gene expression analysis indicated that this early response included activation of several transcription factors that could be involved in pulmonary remodeling. These results show that exposure to a fungus such as Pneumocystis can elicit pulmonary responses that may contribute to morbidity, even without prior sensitization, in the context of certain genetic backgrounds.

Association of STAT6 and ADAM33 single nucleotide polymorphisms with asthma bronchiale and IgE level and its possible epigenetic background

BACKGROUND

ADAM33 and STAT6 belong to the candidate genes that have been commonly associated with asthma, bronchial hyperresponsiveness or IgE levels. Our objective was to assess the association of 11 SNPs of the ADAM33 and 6 of the STAT6 and their haplotypes with IgE levels and asthma. We also evaluated the possible role of parental origin of haplotypes on IgE levels.

METHODS

We enrolled 109 children with asthma and 45 healthy controls. Genotyping was performed by TaqMan probes and confirmed by sequencing. Haplotype construction was based on the knowledge of parental genotypes and also inferred by using the EM algorithm and Bayes' theorem.

RESULTS

None of the SNPs were associated with elevated IgE level or asthma. We found that the most frequent STAT6 haplotype ATTCAA (built from rs324012, rs324011, rs841718, rs3024974, rs3024974, rs4559 SNPs, respectively) was associated with elevated total IgE levels (P=0.01) and this haplotype was predominantly transmitted paternally (P<0.001). We compared our results with those of studies performed on German and Australian Caucasian populations and found that rs324011, rs3024974 and rs4559 SNPs in STAT6 should have a major effect on IgE levels. Therefore, we suggest the TCA haplotype alone (built from rs324011, rs3024974 and rs4559 SNPs, respectively) in STAT6 is associated with total IgE elevation.

CONCLUSIONS

The influence of paternal origin of the STAT6 haplotype on IgE levels is surprising but the exact role of possible paternal imprinting in STAT6 regulation should be investigated and confirmed in future studies.

Genetic studies of the etiology of asthma

Asthma is a heterogeneous disease for which a strong genetic basis is firmly established. Although the generally accepted definition includes three domains of symptoms (variable airway obstruction, airway hyper-responsiveness, and airway inflammation), there is general agreement that, rather than being a single disease entity, asthma consists of related, overlapping syndromes. A considerable proportion of asthma is IgE-mediated, but the observation that not all individuals with asthma are atopic adds to the heterogeneity. Although a genetic basis for asthma is undeniable, elucidation of polymorphisms that are "causal" is greatly hampered by variability in the clinical phenotype, which is likely due to the multiple molecular mechanisms underlying the complex pathological processes involved in disease development and progression. One objective of this review is to consider progress that has been made to date in gene discovery in the field of asthma, with a focus on the evolution of molecular genetic methods that have led to the discoveries thus far, and with a particular focus on the major advances owed to the published genome-wide association studies (GWAS) on asthma to date. A second objective is to consider a Darwinian approach toward understanding the genetic underpinnings of asthma, including evidence supporting a modified Hygiene Hypothesis, which suggests that there are co-associations between asthma risk polymorphisms and polymorphisms associated with another IgE-mediated disease, schistosomiasis. The overall conclusion is that the huge research efforts and expense committed to asthma genetics have changed the perception about disease etiology in general and the functional relevance of the asthma genes identified thus far in particular.

Association and gene-gene interactions of eight common single-nucleotide polymorphisms with pediatric asthma in middle china

BACKGROUND

Asthma is a common polygenic disease, caused by complex interactions between multiple genes and environmental factors. Study of the gene-gene interactions would contribute to a new insight into the pathogenesis and therapeutics of asthma.

OBJECTIVE

To evaluate the single and combined associations of eight single-nucleotide polymorphisms loci in five candidate genes with the development of asthma in Chinese children.

METHODS

We examined eight single-nucleotide polymorphisms (SNPs) in five key asthma susceptibility genes and performed single SNP association study, haplotype analysis, and gene-gene interactions analysis in 479 Chinese children, including 252 asthmatic subjects and 227 healthy controls. Genotyping was performed by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) analysis. Haplotype analysis was detected by SHEsis software. Gene-gene interactions were tested using the multifactor dimensionality reduction (MDR) method.

RESULTS

There were significant differences of interleukin (IL)-13 R130Q and IL-13 C1923T in genotype and allele frequency distributions between the asthmatic group and control group. Furthermore, the A allele of IL-13 R130Q and the T allele of IL-13 C1923T were significantly associated with increased risk of asthma (odds ratio [OR] = 1.59, 95% confidence interval [CI] 1.20-2.09, p = .0010; OR = 1.57, 95% CI 1.19-2.08, p = .0014, respectively). By haplotype analysis, the C-G and T-A haplotypes consisting of IL-13 C1923T and IL-13 R130Q and the G-A and A-A haplotypes consisting of IL-4Ralpha I75V and IL-4Ralpha Q576R were significantly associated with asthma (p < .05). Using MDR, the authors detected significant gene-gene interactions with a best six-locus model among IL-4 -C33T, IL-13 R130Q, IL-4Ralpha I75V, IL-4Ralpha Q576R, STAT6 C2892T, and CD14 -C159T on the risk of asthma (OR = 4.43, 95% CI 1.30-15.04, p < .001, by 1000-fold permutation test).

CONCLUSIONS

These data suggest that genetic variants in the IL-13 gene may play an important role in the development of pediatric asthma in Middle China. In addition, the significant gene-gene interactions among IL-4 -C33T, IL-13 R130Q, IL-4Ralpha I75V, IL-4Ralpha Q576R, STAT6 C2892T, and CD14 -C159T may increase an individual's susceptibility to asthma and contribute to the pathogenesis of asthma.

A STAT6 gene polymorphism is associated with high infection levels in urinary schistosomiasis

Th2-mediated immunity is critical for human defence against schistosome, and susceptibility to infection is controlled by a major genetic locus, mapped on the 5q31-q33 region comprising the genes IL4, IL5 and IL13. We have reported an association between the rs1800925 polymorphism in the IL13 promoter and infection levels in a Dogon population (693 subjects in Ségué and 148 in Boul), where Schistosoma haematobium is endemic. In the same population, we investigated whether other polymorphisms in genes involved in type 2 cytokine immune response could affect susceptibility to schistosome infection. By logistic regression analysis, we found an association between a single-nucleotide polymorphism (SNP) in the STAT6 gene (rs324013) and infection levels (P=0.04). We confirmed this association in analyses restricted to subjects under 20 years age and living in Boul, the village with the highest levels of infection (P=0.005). We detected an additive effect of the rs324013 and rs1800925 polymorphisms (P=0.011). These SNPs were not strongly correlated with any other tested markers surrounding the two genes. Furthermore, electrophoretic mobility shift assay has shown that both polymorphisms affect transcription factor binding. These results are consistent with the Th2 cytokine pathway enhancing resistance to schistosome infection in humans.

Association between candidate genes and lung function growth in Chinese asthmatic children

BACKGROUND

Asthma is caused by a complex interaction between multiple candidate genes and environmental factors. The Childhood Asthma Management Program reported lung function decline in a significant proportion of Caucasian asthmatic children, but such a relation has not been studied in other populations. Our group recently reported that interleukin-13 (IL13), interleukin-4 receptor-alpha and thymus and the activation-regulated chemokine interacted to influence asthma and raised plasma total IgE. However, there has not been any study that has addressed the genetic influences for longitudinal lung function growth.

OBJECTIVE

We studied the longitudinal changes in spirometric variables in Chinese asthmatic children, and investigated the influence and interactions between eight different loci in six candidate genes as well as environmental factors affecting lung function growth in these children.

METHODS

Spirometry was performed at baseline and study completion. Genotyping was performed by restriction fragment length polymorphism. Multi-factor dimensionality reduction (MDR) was used to detect any gene-gene or gene-environment interaction.

RESULTS

We prospectively followed 131 Chinese children, aged 9.9 (3.0) years, for 4.5 (0.8) years. Their mean (standard deviation) baseline forced expiratory volume in 1 s (FEV1) was 98.6 (20.6)% of predicted, and FEV1 to forced vital capacity (FVC) ratio was 77.8 (11.3)%. FEV1 and FVC increased by 210 (115) and 248 (148) mL/year during this study, and these changes were significantly larger among males (P<0.0001). Univariate analysis revealed a significant association between annual FEV1 change and C1570T of signal transducer and activator of transcription 6 gene (STAT6; P=0.009). Linear regression confirmed this finding (P=0.041). Using MDR, we detected a significant 3-locus interaction between IL13 R130Q, ADRB2 R16G and STAT6 C1570T for determining change in FVC (P=0.045).

CONCLUSION

Our data suggest that STAT6 may influence lung function growth in asthmatic children. We also found significant interactions among several atopy-related genetic polymorphisms for influencing FVC change.

Genetic haplotypes of Th-2 immune signalling link allergy to enhanced protection to parasitic worms

Parasitic worm infection, allergy and asthma involve increased IgE production, eosinophil activity, mucus secretion and smooth muscle reactivity, effected through Th-2 immune signalling. These pathological features of allergic disorder, common in developed countries, appear to be protective features in resistance to parasitic worm infections prevalent in many developing countries. We investigated how genetic variation in the Th-2 signalling transduction molecule STAT6 relates to these clinical disorders, using immune phenotyping by serum IgE levels and haplotyping nine STAT6 genetic variants in a rural Chinese population, where Ascaris infection is prevalent, and an urban UK population where Ascaris is largely unknown but asthma and allergy are prevalent. We show for the first time that STAT6 haplotypes relate clearly to IgE levels, allergy and worm burden. The haplotypes segregated into two groups: those with raised IgE/low worm burden tended to have increased risk of allergic disorder, whereas low IgE/high worm burden tended to have a reduced risk of allergies. By estimating the mean worm burden for each haplotype in China and the relative risk of asthma for the matching haplotype in the UK, we draw a cross-population comparison and show a negative correlation between worm burden and expected risk of asthma. These data imply that the origin of common up-regulating variants of Th-2 signalling, involving STAT6, promotes asthma and allergy in developed countries, whereas in developing countries it protects against parasitic worm infections. Selective evolutionary mechanisms, driven by parasitic worm infection, may underlie the genetic contribution to risk of allergy and asthma in humans.

Signal transducer and activator of transcription signals in allergic disease

Signal transducer and activator of transcription (STAT) proteins are a group of transcription factors that transmit signals from the extracellular milieu of cells to the nucleus. They are crucial for the signaling of many cytokines that are mediators of allergic inflammation and impact various cell types critical to allergy including epithelial cells, mast cells, lymphocytes, dendritic cells, and eosinophils. Dysregulation of STAT signaling has been implicated in allergic disease, highlighting the importance of these ubiquitous molecules in allergic inflammation and the potential of these pathways as a target for therapeutic intervention. This review will summarize the current understanding of the roles of STAT signaling in allergic disease and the potential of targeting STATs for the treatment of allergic disorders, emphasizing recent observations.

Distribution of signal transducer and activator of transcription 6 gene G2964A polymorphism in Chinese patients with ulcerative colitis

BACKGROUND AND AIMS

The signal transducer and activator of transcription 6 (STAT6) gene is located on chromosome 12q13.3-14.1 just within the IBD2 region and is a key transcription factor involved in interleukin (IL)-4 and IL-13-mediated Th2 response. The aim of the present study was to determine distribution of the STAT6 gene polymorphism in Chinese patients with ulcerative colitis.

METHODS

The G2964A polymorphism in the 3' untranslated region of the STAT6 gene was studied in 84 unrelated Chinese patients with ulcerative colitis and 176 healthy controls by PCR and the amplification created restriction site method. The results were then compared with those from a Dutch study published previously.

RESULT

Significant differences in genotype and allele frequencies of the STAT6 G2964A polymorphism were not found between patients with ulcerative colitis and healthy controls. Subgroups of the patients with ulcerative colitis classified according to the age at onset, sex and location of disease did not differ significantly in the distribution of this polymorphism. However, the genotypes (P < 0.0001, chi-squared = 75.332) and allele frequencies (P < 0.0001, odds ratio = 4.298, 95% confidence interval = 3.070-6.018) were significantly different between the Chinese and Dutch populations.

CONCLUSION

The STAT6 G2964A polymorphism is not involved in the genetic susceptibility to ulcerative colitis in Chinese patients.

Beta(2)-adrenergic receptor polymorphisms and response to salbutamol among Indian asthmatics*

INTRODUCTION

The beta(2)-adrenergic receptor (beta(2)AR or ADRbeta(2)) is the target for beta(2)-agonist drugs used for bronchodilation in asthma and other respiratory diseases. The aim of this study was to identify common single nucleotide polymorphisms (SNPs) and haplotypes in asthmatics and healthy individuals from an Indian population, and determine the influence of beta(2)AR SNPs in responsiveness to beta(2)-agonist therapy in asthma patients.

METHODS

Ten variable SNP sites within a span of 2.193 kb were identified in the beta(2)AR gene by sequencing and genotyping 374 bronchial asthma patients and healthy individuals from an Indian population. Spirometry tests were performed on 80 unrelated patients before and after administration of 200 microg of salbutamol. A post-bronchodilator forced expiratory volume in one second (FEV(1)) change of >or= 15.3% was considered a good response, and a change of<15.3% was defined as a poor response, to salbutamol.

RESULTS

The pattern of linkage disequilibrium between the ten SNPs showed a single, linked SNP block consisting of sites -468, -367, -47, -20, and 79 having strong linkage disequilibrium, while the SNPs at sites -1023, -654, 46, 252, and 523 showed very low linkage with one another and with the linked region. The SNPs were found to be organized into 16 haplotypes in the studied population. We found that patients with a homozygous Arg-16 form at nucleotide position 46 are poor responders with probability of 0.81, and patients with a homozygous Gly-16 form are good responders with a probability of 0.73. The responder status to salbutamol treatment and the genotype at nucleotide position 46 in beta(2)AR gene of an asthmatic patient are significantly associated in the studied Indian population (chi2=9.98, df=2, p=0.0068). Most importantly, this association for responsiveness to salbutamol at nucleotide position 46 is independent of other SNPs in the beta(2)AR gene.

CONCLUSION

This study suggests that the SNP at nucleotide position 46 has particular relevance to pharmacogenetics in the Indian population studied.

Family studies and positional cloning of genes for asthma and related phenotypes

Although it is not yet known how many genes may contribute to the susceptibility or the severity of asthma and related phenotypes, genome-wide screens and positional cloning techniques have been successful in identifying contributing genes in multiple populations. The results of these studies provide additional insight into the molecular mechanisms responsible for the development of a variety of phenotypes. Replication with additional populations--particularly in large-scale studies--has been used to distinguish between false positive results or population-specific effects or to further quantify the conferred risk. Even when individual markers do not replicate in multiple population, association of the same region or gene has been useful in directing future studies. As further understanding of linkage disequilibrium patterns within the genome has allowed greater efficiency for genetic studies, advances in high-throughput genotyping technology, genetic analysis methodologies, and a more in-depth understanding of clinical phenotypes has made genome-wide studies more accessible and cost-effective. In the future, identification of function variants with clinical relevance may be used to influence the diagnosis and treatment of asthma.

The Indian Genome Variation database (IGVdb): a project overview

Indian population, comprising of more than a billion people, consists of 4693 communities with several thousands of endogamous groups, 325 functioning languages and 25 scripts. To address the questions related to ethnic diversity, migrations, founder populations, predisposition to complex disorders or pharmacogenomics, one needs to understand the diversity and relatedness at the genetic level in such a diverse population. In this backdrop, six constituent laboratories of the Council of Scientific and Industrial Research (CSIR), with funding from the Government of India, initiated a network program on predictive medicine using repeats and single nucleotide polymorphisms. The Indian Genome Variation (IGV) consortium aims to provide data on validated SNPs and repeats, both novel and reported, along with gene duplications, in over a thousand genes, in 15,000 individuals drawn from Indian subpopulations. These genes have been selected on the basis of their relevance as functional and positional candidates in many common diseases including genes relevant to pharmacogenomics. This is the first large-scale comprehensive study of the structure of the Indian population with wide-reaching implications. A comprehensive platform for Indian Genome Variation (IGV) data management, analysis and creation of IGVdb portal has also been developed. The samples are being collected following ethical guidelines of Indian Council of Medical Research (ICMR) and Department of Biotechnology (DBT), India. This paper reveals the structure of the IGV project highlighting its various aspects like genesis, objectives, strategies for selection of genes, identification of the Indian subpopulations, collection of samples and discovery and validation of genetic markers, data analysis and monitoring as well as the project's data release policy.

The role of genetics in the development of asthma and atopy

PURPOSE OF REVIEW

The mapping of complex traits such as asthma and atopy is one of the most important and central areas of human genetics. This article will present an overview of the current status of genetic studies of asthma and atopy using genome screens and association studies that have occurred in the literature since January 2003.

RECENT FINDINGS

Many regions of the genome have been found to have linkage with the phenotypes of asthma and atopy. Over 70 variants in candidate genes have been reported to be associated with these phenotypes. The main regions these variants have been found are on chromosomes 2q, 5q, 6p, 11q, 12q, 16q and 17q. Five potential asthma susceptibility genes or complexes have been identified using a positional approach. These are ADAM33, DPP10, PHF11 and SETDB2, GPRA and SPINK5. It is evident that environmental factors will influence the expression of genes and the ultimate clinical phenotype of asthma and atopy.

SUMMARY

The development of asthma and atopy involves many genes and environmental factors. An understanding of their genetic basis has great implications for their management.

Association of an intragenic microsatellite marker in the CC16 gene with asthma in the Indian population

The gene for Clara cell secretory protein (CC16) is an ideal candidate for investigating genetic predisposition to asthma because of its role in the airway as an anti-inflammatory molecule, differences in its levels between asthmatics and healthy controls, and its genetic location (11q13). We investigated the association of an SNP (A38G) and an intragenic repeat polymorphism in the CC16 gene with asthma and its associated traits, such as total serum IgE levels, in a case control as well as in a family based study design. A significant association was observed for the microsatellite repeat at the level of alleles and genotypes with asthma (P<0.05) in both the study designs. However, no association was observed for the A38G SNP with asthma. When haplotypes were constructed for these two loci and compared, the haplotype A_18 was found at higher frequency in patients (OR=1.59, 95%CI=1.08, 2.33, P=0.016). Also, in the family based design, a biased transmission was observed for haplotypes from parents to affected offspring (P=0.003). Individually, haplotype A_18 showed preferential transmission (82.6%) to affected offspring (P=0.001), thereby confirming the case-control results. In summary, this is the first study identifying the CC16 gene to be associated with asthma in the Indian population.