ADAM33 polymorphisms and phenotype associations in childhood asthma

BACKGROUND: A disintegrin and metalloproteinase (ADAM) 33 has been implicated as an asthma susceptibility gene by using a positional cloning approach. However, genetic linkage of asthma phenotypes to chromosome 20p13 (the location of ADAM33) has not been observed in most asthma genome scans, and it is unclear whether these associations with ADAM33 are broadly generalizable. OBJECTIVE: To examine whether ADAM33 is associated with asthma in a North American population of childhood asthmatic patients. METHODS: We performed a family-based association study by using 652 nuclear families ascertained through asthmatic subjects enrolled in a large randomized clinical trial. Seventeen ADAM33 single nucleotide polymorphisms (SNPs; including 9 associated with asthma in the initial report) were genotyped by mass spectrometry. Single-SNP and haplotype association analysis was performed. RESULTS: Among white and African American subjects, no single-SNP association with asthma was observed. However, a common 16-SNP haplotype (frequency, 14.6% in white subjects) was associated with asthma (P=.006). Two SNPs in strong linkage disequilibrium (T1 and T+1) were marginally associated with asthma in the Hispanic cohort (P=.04). These data provide marginal support for an asthma locus in the ADAM33 genomic region. However, the magnitudes of the observed associations are modest at best and are inconsistent with the original report. CONCLUSIONS: We conclude that either ADAM33 has only modest effects on asthma susceptibility, and the initial reports of association were a result of analysis in a selected population, or the initial findings were a result of chance. It is also possible that the true asthma susceptibility locus in this genomic region is near, but not at, ADAM33.     

Polymorphisms in ADAM33 are associated with allergic rhinitis due to Japanese cedar pollen

BACKGROUND: A recent report provided evidence that a disintegrin and metalloprotease domain 33 (ADAM33), a member of the ADAM family, is a novel susceptibility gene in asthma linked to bronchial hyper-responsiveness. However, there has been no investigation of the genetic role of ADAM33 variants in nasal allergy. OBJECTIVE: The purpose of this study was to test the association between ADAM33 polymorphisms and Japanese cedar pollinosis (JCPsis), a most common seasonal allergic rhinitis in Japan. METHODS: We conducted a case-control association study among a Japanese population, involving 95 adult individuals with JCPsis and 95 normal healthy controls. A total of 22 single-nucleotide polymorphisms (SNPs) in ADAM33 were genotyped using PCR-based molecular methods. RESULTS: Six SNPs of ADAM33 gene, three in introns (7575G/A, 9073G/A and 12540C/T) and three in the coding region (10918G/C, 12433T/C and 12462C/T), were strongly associated with JCPsis (P = 0.0002-0.022 for absolute allele frequencies) and most of the SNPs were in linkage disequilibrium with each other. A higher frequency of the common alleles of these SNPs was noted for the subjects with JCPsis in comparison with healthy controls. We also identified a haplotype associated with the disease susceptibility. In addition, associations were found between ADAM33 polymorphisms and various cedar pollinosis phenotypes including clinical severity, eosinophil counts in nasal secretion and allergen-specific IgE levels in sera, but not total serum IgE levels. CONCLUSION: These results indicate that polymorphisms in the ADAM33 gene are associated with susceptibility to allergic rhinitis due to Japanese cedar pollen, but the functional relationship still needs clarification.     

ADAM33 polymorphism: association with bronchial hyper-responsiveness in Korean asthmatics

BACKGROUND: A disintegrin and metalloprotease 33 (ADAM33) is expressed in the lung by fibroblasts and bronchial smooth muscle cells. Given its structure and cellular provenance, ADAM33 may be associated with airway remodelling and bronchial hyper-responsiveness. Single nucleotide polymorphisms (SNPs) and haplotypes of the ADAM33 gene have previously been associated with asthma susceptibility in the Caucasian population. OBJECTIVE AND METHODS: To assess whether genetic variants of ADAM33 are related to asthma in a Korean population, we conducted an association study of the ADAM33 gene with asthma susceptibility, bronchial hyper-reactivity and serum IgE in Korean asthmatics (n=326) and normal controls (n=151). Five of the 14 polymorphisms originally reported to be associated with asthma development (S1 G>A, T1 T>C, V-1 C>A, V1 T>A, V4 C>G) were genotyped using single base extension and electrophoresis. Haplotypes and their frequencies were inferred using the algorithm implemented by the software Arlequin. Allele frequencies of each SNP and haplotypes were compared between the patients and the normal controls using logistic regression analysis. RESULTS: There was no significant difference in the distribution of SNPs and the six haplotypes between asthmatics and normal controls. All single SNPs and six haplotypes in ADAM33 were also analysed for the association with level of PC(20) using general linear models. The distribution of the T1 T>C SNP and one haplotype (ht4: GCGG) showed significant association with log-transformed PC(20) methacholine level in the asthma patients (P=0.03 and 0.0007, respectively, using a co-dominant model). CONCLUSION: Polymorphism of ADAM33 may contribute to development of BHR in asthma.     

Association of a disintegrin and metalloprotease 33 (ADAM33) gene with asthma in ethnically diverse populations

BACKGROUND: Asthma is a complex genetic disease characterized by reversible intermittent airway obstruction and respiratory symptoms primarily caused by acute and chronic bronchial inflammation. Recently, a gene potentially involved in airway remodeling, a disintegrin and metalloprotease 33 (ADAM33), was implicated in asthma susceptibility. OBJECTIVE: We sought to determine whether polymorphisms in ADAM33 are associated with asthma or closely related phenotypes in 4 different asthma populations. METHODS: Eight single nucleotide polymorphisms (SNPs) were evaluated in the 3' portion of ADAM33 in 4 unique asthma populations (African American, US white, US Hispanic, and Dutch white). These SNPs were previously reported to be associated with asthma in white populations from the United States and United Kingdom. RESULTS: Significant associations were observed with at least one SNP and asthma in each population (P =.0009-.04). Related phenotypes that included total serum IgE levels and skin test responsiveness were also associated (P =.003-.05). However, no single SNP was associated across all populations. Additionally, haplotype analysis revealed that no single haplotype accounted for asthma susceptibility risk, although potential risk haplotypes existed within some of the populations. CONCLUSION: Replication of the original ADAM33 findings in these 4 additional asthma populations suggests that this gene (and perhaps others that interact with it) is important in the development and pathogenesis of asthma.     

ADAM33 polymorphisms are associated with asthma susceptibility in a Japanese population

BACKGROUND: Asthma is the most common chronic disorder in childhood, and asthma exacerbation is an important cause of childhood morbidity and hospitalization. Asthma is believed to be a complex disorder involving genetic and environmental factors, and several asthma susceptibility loci have been identified through genome-wide screening. A disintegrin and metalloprotease 33 (ADAM33) was the first asthma susceptibility gene to be discovered by positional cloning in 2002. OBJECTIVE: The aim of the present study was to investigate whether single-nucleotide polymorphisms (SNPs) in ADAM33 are associated with childhood asthma in the Japanese population. METHODS: Twenty-three ADAM33 SNPs were genotyped by fluorescence correlation spectroscopy with the use of DNA from 155 families (538 members) identified through children with atopic asthma. The transmission disequilibrium test (TDT) was performed for family-based association study. RESULTS: TDT revealed that minor alleles of S+1, ST+4, and T2 SNPs were over-transmitted to asthma-affected offspring (P<0.05). According to the haplotype TDT, no haplotype of ADAM33 was transmitted preferentially to asthmatic offspring. CONCLUSION: Our results confirm the involvement of ADAM33 in the development of childhood asthma among the Japanese.     

Association between ADAM33 T1 polymorphism and susceptibility to asthma in Asians

Objective

The aim of this study was to determine whether the ADAM33 (a disintegrin and metalloproteinase domain 33) T1 (rs2280091), T2 (rs2280090), and ST+7 (rs574174) polymorphisms confer susceptibility to asthma.

Methods

A meta-analysis stratified by ethnicity and age was conducted on associations between the ADAM33 T1, T2, and ST+7 polymorphisms and asthma.

Results

Eleven studies, which included 4,124 patients and 7,094 controls, were available for the meta-analysis. Meta-analysis revealed an association between asthma and the ADAM33 T1 GG genotype [odds ratio (OR)?=?2.257, 95?% confidence interval (CI)?=?1.577–3.228, p?=?8.42?×?10^?7]. Stratification by ethnicity indicated an association between this genotype and asthma in Asians (OR?=?2.683, 95?% CI?=?1.799–4.001, p?=?1.31?×?10^?7), and stratification by age indicated an association between it and asthma in adults (OR?=?1.895, 95?% CI?=?1.005–3.573, p?=?0.048). However, no association was found between asthma and the ADAM33 T2 and ST+7 polymorphisms.

Conclusions

This meta-analysis demonstrates that the ADAM33 T1 polymorphism confers susceptibility to asthma in Asians, but no association was found between the ADAM33 T2 and ST+7 polymorphisms and asthma susceptibility.     

The -1541 C>T and +4259 G>T of TIM-3 polymorphisms are associated with rheumatoid arthritis susceptibility in a Chinese Hui population

The T‐cell immunoglobulin and mucin domain 3 (TIM‐3) has been shown to be associated with susceptibility to rheumatoid arthritis (RA). In this study, we investigated the association of four single‐nucleotide polymorphisms (SNPs) of the TIM‐3 gene with RA susceptibility in Chinese Hui and Han groups. Using restriction fragment length or sequence‐specific primer–polymerase chain reaction (PCR), patients with RA and nonarthritis control individuals from these two ethnicities were analysed for SNPs of ?1541 C>T, ?882 T>C, ?574 T>G and +4259 G>T, in the TIM‐3 gene. Our results demonstrated that the polymorphisms of +4259 G>T SNP of TIM‐3 gene was associated with the RA susceptibility in both the Hui (P < 0.01) and Han populations (P < 0.05). However, the ?1541 C>T and ?574 T>G SNPs were distinctly associated with RA for the Hui and Han populations, respectively. In addition, haplotype analysis found no statistically differences in the distribution of nine detected haplotype frequency between patients with RA and controls in this study (P > 0.05). These findings suggest that polymorphism of +4259 G>T in TIM‐3 gene may be one of the most important genetic factors associated with the RA susceptibility among different populations, and genetic variations of TIM‐3 gene contribute to RA susceptibility among different populations.     

<Emphasis Type="Italic">ADAM33 </Emphasis>polymorphisms are associated with aspirin-intolerant asthma in the Japanese population

Multiple single nucleotide polymorphisms (SNPs) within ADAM33 have been reported to be associated with asthma and bronchial hyper-responsiveness in Caucasian populations. We examined whether these SNPs contribute to a predisposition to asthma, especially aspirin-intolerant asthma (AIA), in the Japanese population. Ten polymorphic sites (ST+4, ST+7, T1, T2, T+1, V-3, V-2, V-1, V4, V5) were genotyped in 102 AIA patients, 282 aspirin-tolerant asthma (ATA) patients and 120 control (CTR) subjects by direct sequencing. Haplotype frequencies were estimated by the expectation-maximization method. Differences in allele and haplotype frequencies among phenotypes were analyzed by the chi-square and permutation tests. ST+7, V-1 and V5 sites in the AIA group were significantly different from those in the ATA group (P=0.034–0.004) and from those in the CTR group (P=0.019–0.002). Haplotypes at three sites (ST+7, V-1, and V5) were significantly different in frequency between the AIA and ATA (P=0.008) or CTR (P=0.001) groups. Sequence variations in ADAM33 are likely to correlate with susceptibility to AIA in the Japanese population. The authors declare that they have no conflict of interest.     

Association of ADAM33 polymorphisms with childhood asthma in a northern Chinese population

Background

Genetic factors contribute to the increasing incidence of childhood asthma. The ADAM33 (a disintegrin and metalloprotease domain-containing protein 33) gene, discovered through positional cloning, is the first to be associated with asthma and bronchial hyperresponsiveness. This case–control study conducted in a Han Chinese population in northern China compared the genotypes of child asthmatic patients to healthy controls for the presence of 6 single nucleotide polymorphisms (SNPs) in the ADAM33 gene.

Methods

The study population was composed of 412 children with asthma and 397 healthy controls. We genotyped 6 SNPs (F + 1, T + 1, T2, T1, V4, and Q-1) of ADAM33 with the PCR-restriction fragment length polymorphism (PCR-RFLP) method. Data were statistically analyzed to determine if an association existed between these genotypes and childhood asthma morbidity.

Results

Three SNPs (T + 1, T1, and V4) and 4 haplotypes (H1, H3, H5, and H8) were strongly associated with childhood asthma in children of northern China compared to healthy controls (P < 0.05), whereas the other tested SNPs and haplotypes demonstrated no significant relationship.

Conclusion

The ADAM33 gene plays an important role in facilitating susceptibility to childhood asthma in this Han Chinese population.     

Asthma is associated with single-nucleotide polymorphisms in ADAM33

BACKGROUND : The ADAM33 gene has recently been associated with asthma and bronchial hyper-reactivity. It codes for a disintegrin and metalloproteinase that triggers intra- and extracellular signalling by protein shedding. OBJECTIVE : We examined whether polymorphisms in ADAM33 are associated with asthma and related traits in two German populations. METHODS : We genotyped 15 intragenic single-nucleotide polymorphisms (SNPs) by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry of allele-specific primer extension products. The transmission disequilibrium test was used for association analysis in the German asthma family study. Additionally, we tested for association of these SNPs in a case-control sample from the European Community Respiratory Health Study using Armitage's trend test. RESULTS : In both studies, we found SNPs that were significantly associated with asthma and related traits. In the family study, significant associations were observed for the SNPs F+1, ST+4 and ST+5 (with the lowest P-value for F+1, P=0.005). Remarkably, this association is seen even in the absence of linkage with two microsatellite markers from a previous genome scan either 3.1 million bases (Mb) up- or 5.6 Mb downstream. In the case-control study, SNP ST+7 (P=0.008) was significantly associated with asthma. Some of these SNPs overlapped with those found to be associated with elevated total IgE levels and bronchial hyper-responsiveness. CONCLUSION : This study replicates the recently published association between asthma and ADAM33 gene variants. However, most of the associated SNPs were at non-identical positions in the German, UK and US samples. As linkage disequilibrium is high among the tested SNPs, and there is no known functional polymorphism, either not-tested variants in ADAM33, unknown regulatory elements or a gene in close proximity is responsible for this association.     

Lack of association between ADAM33 gene and asthma in a Chinese population

Asthma is a complex polygenic disease with gene-environment interactions being important. It has been previously suggested that ADAM33, which is a member of a gene family that encodes membrane-anchored proteins with a disintegrin and a metalloprotease domain, is primarily expressed in lung fibroblasts and bronchial smooth muscle cells and has been associated with airway remodelling and bronchial hyperresponsiveness. A significant association has previously been demonstrated between single nucleotide polymorphisms (SNPs) and haplotypes of the ADAM33 and asthma in ethnically diverse populations. To assess whether SNPs or haplotypes of ADAM33 are related to asthma in a Chinese Han population, we genotyped three SNPs of ADAM33 (7575G/A in intron 6, 11188A/T in intron 19, and 12433T/C in exon 20) in a case-control study involving 296 patients with asthma and 270 healthy controls. No significant association was detected between these three SNPs and asthma susceptibility in the Chinese population.     

Association of Interleukin 10 Gene Polymorphisms with Autoimmune Thyroid Disease: Meta‐Analysis

The aim of this study was to perform a meta‐analysis of eligible studies and to derive a precise estimate of the association between interleukin 10 (IL10) polymorphisms and susceptibility to autoimmune thyroid disease (AITD). Meta‐analyses were conducted on the associations between AITD and the ‐1082 G/A (rs1800896), ‐819 C/T (rs1800871) and ‐592 C/A (rs1800872) polymorphisms in IL10, and the haplotype of these polymorphisms and AITD. A total of 2903 AITD patients and 3060 controls in 10 eligible studies were included in the meta‐analysis. This meta‐analysis showed significant associations between IL10 at the ‐1082 G allele and overall AITD (OR: 1.44, 95% CI 1.13–1.82, P = 0.003), but no association between the IL10 ‐592 C allele and the ‐819 C allele and AITD. Subgroup studies demonstrated significant associations between the ‐1082 G allele and susceptibility to Graves’ disease. Ethnicity‐specific meta‐analysis revealed significant associations between the ‐1082 G allele and AITD susceptibility in Asian populations; however, in Middle Eastern populations, no association was evident. Meta‐analysis of the IL10 haplotype revealed an association between the ATA haplotype and AITD (OR: 1.17, 95% CI 1.00–1.36, P = 0.04). Meta‐analysis demonstrates that the IL10 polymorphisms are associated with susceptibility to AITD.     

Association of the HLA‐G 3′UTR polymorphisms with colorectal cancer in Italy: a first insight

This study aimed to explore functional and regulatory polymorphisms and haplotypes at the HLA‐G 3′UTR region in colorectal cancer development. The presence of nonpolymorphic variants was also evaluated. Three‐hundred and eight patients with colorectal cancer and 294 healthy controls were analysed at the germinal level. We found an association with increased risk of colorectal cancer for +2960 14‐bp INDEL, +3196 C>G SNPs and UTR‐2 haplotype, and a ‘protective’ role for +3003 T>C, +3010 C>G polymorphisms and UTR‐4 haplotype. We detected in 3 distinct patients, a novel nucleotide change (+3037 C>A) and 2 already described rare variants, +3032 G/C (EUR MAF = 0.1%) and +3092 G/T (EUR MAF = 0%). This is the first study showing associations between different polymorphisms in the HLA‐G 3′UTR and colorectal cancer susceptibility.     

Two polymorphisms in the TIM‐4 gene are associated with asthma in a Chinese Han population

The gene family of the T cell immunoglobulin and mucin domain (TIM) proteins encodes cell surface receptors that are involved in the regulation of Th1‐ and Th2‐cell‐mediated immunity. TIM‐1 gene has been found to be associated with asthma in several populations. TIM‐4, the natural ligand for TIM‐1, may influence the susceptility to asthma.To investigate the association of the TIM‐4 gene polymorphisms with asthma in a Chinese Han population. Three single nucleotide polymorphisms (SNPs) in TIM‐4 gene, rs6882076, rs12658558 and rs4702747, were genotyped in 551 unrelated asthma patients and 549 healthy controls. We found that two SNPs of the TIM‐4 gene, rs6882076 and rs4702747, were associated with asthma susceptibility in our study population (with P‐values = 0.009 and 0.005 respectively). No association was observed between asthma and rs12658558. Our results suggest that TIM‐4 gene polymorphisms are associated with asthma in a Chinese Han population.     

TGF-β1和ADAM33基因交互作用与儿童哮喘易感性及严重程度相关性

目的:探讨转化生长因子β1(TGF-β1)和解整合素金属蛋白酶33(ADAM33)基因单核苷酸多态性与儿童哮喘易感性及严重程度相关性。方法:采用以医院为基础的病例对照研究(110例哮喘患儿和144例对照)方法,三个多态性位点(V4、T2、T869C)用聚合酶链反应-限制性片段长度多态性分析(PCR-RFLP)技术进行基因分型,应用MDR软件分析基因各位点之间交互作用。结果:TGF-β1基因的T869C位点基因型及等位基因频率分布在哮喘组和对照组比较差异均无统计学意义(P>0.05)。哮喘组ADAM33基因V4位点C和T2位点A等位基因频率显著高于对照组(P<0.01),而V4位点的CC基因型及T2位点的GA基因型分布在轻中度哮喘组与对照组比较差异无统计学意义(P>0.05),T2位点的AA基因型分布在重度哮喘与对照组比较无显著性差异(P>0.05)。MDR交互作用分析显示,ADAM33基因V4和T2位点构成的2个位点最佳模型;ADAM33基因位点V4、T2和TGF-β1位点T869C构成的3个位点最佳模型两组比较均有统计学差异(P<0.05)。结论:ADAM33基因V4和T2位点与儿童哮喘发生及其严重程度相关,同时TGF-β1基因T869C位点与ADAM33基因V4和T2位点均具有明显交互作用     

A disintegrin and metalloprotease 33 (ADAM33) gene polymorphisms and the risk of asthma: A meta-analysis

Polymorphisms in the ADAM33 gene have been associated with asthma, but the data are controversial. Therefore, we reviewed the related studies and quantitatively summarized the associations between ADAM33 polymorphisms and asthma risk using meta-analysis. A dominant model (AA+Aa vs. aa), recessive model (AA vs. Aa+aa), additive model (AA vs. aa) and allelic model (A vs. a) were used to estimate the association between ADAM33 polymorphism and asthma risk. A total of 29 case–control studies referring to 14 SNPs were identified: rs2280091(T1), rs2787094(V4), rs528557(S2), rs2280090(T2), rs511898(F+1), rs44707(ST+4), rs3918396(S1), rs543749(V−1), rs574174(ST+7), rs597980(ST+5), rs2853209(S+1), rs2280089(T+1), rs612709(Q−1), and rs3746631(V5). The results indicated that S1, V−1, V5, S+1, S2, ST+4, ST+7, ST+5, and Q−1 were not associated with asthma. Significant associations were found with the T1, V4, F+1 and T+1 polymorphisms in the overall population. In the subgroup analysis by ethnicity, a positive result was only found for the T1, V4, F+1 and T2 polymorphisms in Asia but not in Europe or Latin America. This meta-analysis provides evidence that the T1, V4, F+1, T2, and T+1 polymorphisms in the ADAM33 gene are risk factors for asthma, especially in the Asian population.     

Polymorphisms in the myosin light chain kinase gene that confer risk of severe sepsis are associated with a lower risk of asthma

BACKGROUND: Myosin light chain kinase (MYLK) is a multifunctional protein involved in regulation of airway hyperreactivity and other activities relevant to asthma. OBJECTIVE: To determine the role of MYLK gene variants in asthma among African Caribbean and African American populations. METHODS: We performed association tests between single nucleotide polymorphisms (SNPs) in the MYLK gene and asthma susceptibility and total serum IgE concentrations in 2 independent, family-based populations of African descent. Previously we identified variants/haplotypes in MYLK that confer risk for sepsis and acute lung injury; we compared findings from our asthma populations to findings in the African American sepsis and acute lung injury groups. RESULTS: Significant associations between MYLK SNPs and asthma and total serum IgE concentrations were observed in the African Caribbean families: a promoter SNP (rs936170) in the smooth muscle form gave the strongest association (P = .009). A haplotype including rs936170 corresponding to the actin-binding activity of the nonmuscle and smooth muscle forms was negatively associated with asthma (eg, decreased risk) in both the American (P = .005) and Caribbean families (P = .004), and was the same haplotype that conferred risk for severe sepsis (P = .002). RNA expression studies on PBMCs and rs936170 suggested a significant decrease in MYLK expression among patients with asthma with this variant (P = .025). CONCLUSION: MYLK polymorphisms may function as a common genetic factor in clinically distinct diseases involving bronchial smooth muscle contraction and inflammation. CLINICAL IMPLICATIONS: Genetic variants in MYLK are significantly associated with both asthma and sepsis in populations of African ancestry.     

Association of ADAM33 gene polymorphisms with COPD in the Mongolian population of China

Background: Chronic obstructive pulmonary disease (COPD) is a respiratory disorder with increasing prevalence and mortality, influenced by both environmental and genetic factors. ADAM33 gene has been found to be associated with asthma, declined lung function and COPD.

Aim: The aim of this study was to find out if SNPs in ADAM33 (V4, T+1, T1, T2, S1, S2, Q?1 and F+1) play any role in genetic susceptibility to COPD in the Mongolian population of China.

Subjects and methods: Two hundred and fifteen Mongolian COPD patients and 223 Mongolian healthy individuals were recruited for the study. Eight polymorphic loci (V4, T+1, T2, T1, S2, S1, Q?1, and F+1) of ADAM33 were selected for genotyping. Genotyping was carried out using the Polymerase Chain Reaction and Restriction Fragment Length polymorphism (PCR-RFLP) method.

Results: Seven SNPs in ADAM33 were associated with COPD (T+1, p?=?0.014; T2, p?=?0.018; T1, p?=?0.048; S2, p?=?0.003; S1, p?=?0.000; Q?1, p?=?0.000 and F+1, p?=?0.000), even after Bonferroni correction, SNPs S2, S1, Q?1 and F+1 remained significant. Haplotype analysis showed that the frequencies of haplotype H1 (GGAGGGT), H5 (GGAGGGC) and H10 (GGGGAGT) were significantly higher in the COPD group than in the control group (p?=?0.002, 0.031 and 0.009, respectively). In contrast, the haplotype H11 (GGACAGC) was more common in the control group than in the case group (p?=?0.015).

Conclusions: Seven SNPs in ADAM33 were associated with COPD in the Mongolian population of China.     

ADAM33 haplotypes are associated with asthma in a large Australian population

The ADAM33 gene has recently been identified as being a potentially important asthma candidate gene, and polymorphisms in this gene have been shown to be associated with asthma and bronchial hyperresponsiveness in Caucasian individuals from several populations. We performed chip-based matrix-assisted laser desorption/ionisation time-of-flight (MALDI-TOF) mass spectrometry using the MassARRAY system and multiplexed genotyping assays to investigate the association between 10 single nucleotide polymorphisms (SNPs) in the ADAM33 gene (F_+1, Q_-1, S_1, ST_+4, ST_+7, V_-2, V_-1, V_2, V_4, V_5) and asthma and asthma severity in a large Australian Caucasian population of nonasthmatic controls (n = 473), and patients with mild (n = 292), moderate (n = 238) and severe (n = 82) asthma. No significant association was found between any one of the 10 SNPs and asthma or asthma severity, however, there was a significant global haplotypic association with asthma (P = 0.0002) and disease severity (P = 0.0001), driven by the combination of two key SNPs, V_-1 and ST_+7. A meta-analysis of all the genetic studies conducted to date found significant between-study heterogeneity, likely to reflect population stratification. Our analysis of ADAM33 haplotypes further suggests a likely role for ADAM33 in the asthma phenotype, although it does not exclude an association with another locus in linkage disequilibrium with ADAM33.