Identification of novel SNPs in the interleukin 6 receptor gene (IL6R)

The human interleukin-6 receptor (IL6R) is responsible for signal transduction of IL6 that might have associations with immune diseases and various infectious diseases. We have sequenced all 10 exons including the putative splicing site to identify single nucleotide polymorphisms in IL6R. Seven novel single nucleotide polymorphisms (SNPs) were identified; one SNP in the promoter region (-183G>A), one synonymous SNP in exon 2 (24013G>A: Ala31Ala), one non-synonymous SNP in exon 9 (48892A>C: Asp358Ala) and four in introns (29753A>C, 42700T>C, 48869T>A and 59818C>T). The frequencies of each SNP in the Korean population (n=300) were 0.48 (-183 G>A), 0.13 (24013 G>A), 0.41 (29753A>C), 0.41 (42700T>C), 0.1 (48869T>A), 0.42 (48892A>C), and 0.07 (59818C>T), respectively. Haplotypes and their frequencies were estimated by the EM algorithm. Linkage disequilibrium coefficients (/D'/) between each SNP pair were also calculated. The information on SNPs and haplotypes in IL6R would be useful for genetic studies of this gene.     

Identification of 25 new mutations in 40 unrelated Spanish Niemann-Pick type C patients: genotype-phenotype correlations

To better characterize Niemann-Pick type C (NPC) in Spain and improve genetic counselling, molecular analyses were carried out in 40 unrelated Spanish patients. The search identified 70/80 alleles (88%) involving 38 different NPC1 mutations, 26 of which are described for the first time. No patient with NPC2 mutations was identified. The novel NPC1 mutations include 14 amino acid substitutions [R372W (c.1114C>T), P434L (c.1301C>T), C479Y (c.1436G>A), K576R (c.1727G>A), V727F (c.2179G>T), M754K (c.2261T>A), S865L (c.2594C>T), A926T (c.2776G>A), D948H (c.2842G>C), V959E (c.2876T>A), T1036K (c.3107C>A), T1066N (c.3197C>A), N1156I (c.3467A>T) and F1224L (c.3672C>G)], four stop codon [W260X (c.780G>A), S425X (c.1274C>A), C645X (c.1935T>A) and R1059X (c.3175C>T)], two donor splice-site mutations [IVS7+1G>A (g.31432G>A) and IVS21+2insG (g.51871insG)], one in-frame mutation [N961_F966delinsS (c.2882del16bpins1bp)] and five frameshift mutations [V299fsX8 (c.895insT), A558fsX11 (c.1673insG), C778fsX10 (c.2334insT), G993fsX3 (c.2973_78delG) and F1221fsX20 (c.3662delT)]. We also identified three novel changes [V562V (c.1686G>A), A580A (c.1740C>G) and A1187A (c.3561G>T)] in three independent NPC patients and five polymorphisms that have been described previously. The combination of these polymorphisms gave rise to the establishment of different haplotypes. Linkage disequilibrium was detected between mutations C177Y and G993fsX3 and specific haplotypes, suggesting a unique origin for these mutations. In contrast, I1061T mutation showed at least two different origins. The most prevalent mutations in Spanish patients were I1061T, Q775P, C177Y and P1007A (10, 7, 7 and 5% of alleles, respectively). Our data in homozygous patients indicate that the Q775P mutation correlates with a severe infantile neurological form and the C177Y mutation with a late infantile clinical phenotype.     

Identification of novel variants in transforming growth factor-beta 1 (TGFB1) gene and association analysis with bone mineral density

Human transforming growth factor-beta1 (TGFB1) is a family of polypeptides that regulate cell growth, cell differentiation, and cell function as a multifunctional regulator of cellular activity. TGFB1 is produced by osteoblasts and stored in substantial amounts in the bone matrix, which is an important regulator of both skeletal development and homeostasis of bone metabolism. In the present study, we identified four new polymorphisms in TGFB1 and examined whether these polymorphisms are risk factors for osteoporosis. We have sequenced all exons including in the promoter region up to -1,800bp to identify additional genetic polymorphisms in TGFB1. Four novel polymorphisms were newly identified: one in 5' region (g.14129555_14129557dupAGG), one in promoter region (g.14128838C>T), and two in intron (g.14106505G>A and g.14106215G>A). Two known SNPs (g.14128554C>T and g.14127139T>C) were also confirmed. The frequencies of each SNP were 0.479 (g.14129555_14129557dupAGG), 0.007 (g.14128838C>T), 0.478 (g.14128554C>T), 0.476 (g.14127139T>C), 0.016 (g.14106505G>A), and 0.004 (g.14106215G>A) in the Korean population (n=1,885), respectively. Haplotypes and their frequencies were estimated by EM algorithm, and linkage disequilibrium coefficients (mid R:/D'/: and r2) between polymorphism pairs were calculated. We analyzed genetic associations of TGFB1 polymorphisms and haplotypes with spinal bone mineral density (BMD) value of 433 postmenopausal Korean women. By statistical analysis, we could not find any associations with spinal BMD. The information from this study of the critical TGFB1 would be useful for genetic studies of other diseases.     

Haplotyping of wild type and I278T alleles of the human cystathionine beta-synthase gene based on a cluster of novel SNPs in IVS12

Homocystinuria is most frequently due to deficiency of cystathionine beta-synthase (CBS). We identified IVS12 as a polymorphism hot spot of the human CBS gene and report five novel single nucleotide polymorphisms (SNPs): g.13514G>A, g.13617A>G, g.13715C>T, g.13800G>A, and g.13904C>T. Analyzing 50 control DNA samples of unaffected and unrelated subjects of German origin the observed frequencies of heterozygosity were 0.02, 0.36, 0.18, 0.36, and 0.36, respectively. These polymorphic markers were combined into four distinct IVS12-haplotypes A1, A2, B1, and B2, revealing frequencies of 0.75, 0.01, 0.15, and 0.09, respectively, with an observed overall frequency of heterozygosity at 0.38. This haplotype system and the SNP c.699 were employed in the analysis of ten alleles affected by the most prevalent CBS mutation, c.833T>C (exon 8; I278T). We found that the I278T alleles segregate with at least two distinct haplotypes characterized by upstream and downstream polymorphic sites instead of sharing a common ancestral haplotype. This was a remarkable finding even in patients with very similar ethnic background. The novel haplotype system may facilitate future studies on the evolution of the CBS gene and might be suited for genotyping of families affected by homocystinuria.     

温州地区汉族正常人群CYP1A2基因多态性分布特征

目的检测CYP1A2基因多态性在温州地区汉族正常人群的分布特征。方法采用聚合酶链反应（PCR）产物直接测序法检测108例随机血液样本DNA中CYP1A2基因序列单核苷酸多态性位点（SNP）的分布。对检测到的3个多态位点2159G〉A、3613T〉C、5347C〉T,进一步采用PCR技术分析472例正常人位点的基因型频率和等位基因频率。结果 （1）2159 G〉A位点：G和A等位基因的频率分别为93.8%,6.2%,GG、GA、AA基因型频率分别为87.7%、12.1%、0.2%（χ2=0.325,P〉0.05）;（2）3613 T〉C位点：T和C等位基因的频率分别为97.9%、2.3%,TT、TC、CC基因型频率分别为95.3%、4.4%、0.3%（χ2=0.298,P〉0.05）;（3）5347 C〉T位点：C和T等位基因的频率分别为87.9%、12.1%。CC、CT、TT基因型分布频率分别为77.8%、20.3%、1.9%（χ2=0.742,P〉0.05）;（4）2159 G〉A、5347 C〉T组成的单倍型频率为3.2%。结论温州地区汉族正常人群CYP1A2基因存在2159G〉A、3613T〉C、5347C〉T多态位点。     

PMM2 mutation spectrum, including 10 novel mutations, in a large CDG type 1A family material with a focus on Scandinavian families

Carbohydrate-deficient glycoprotein syndrome type IA (CDG IA) is an autosomal recessive disease characterized clinically by severe involvement of the central and peripheral nervous system, and biochemically by complex defects in carbohydrate residues in a number of serum glycoproteins. CDG IA is caused by mutations in the PMM2 gene located in chromosome region 16p13. In this study, 61 CDG type IA patients (122 chromosomes) were screened for mutations in the PMM2 gene using a combination of SSCP and sequence analysis. More than 95% of the mutations could be detected. All of them were missense mutations. Mutations 422G>A and 357C>A were strikingly more common in the material and comprised 58% of mutations detected. Of the 20 mutations found, 10 were not reported previously. Seven mutations, e.g. 26G>A (five alleles) and 548T>C (seven alleles), were found only in Scandinavian families. The most common genotype was 357C>A/422G>A (36%). Three patients were homozygous, 357C>A/357C>A (two cases), and 548T>C/548T>C (one case). No patients homozygous for the most common mutation 422G>A were detected. The different mutations were clustered e.g., in that most were located in exon 5 (five) and exon 8 (six), while no mutation was detected in exon 2. When the frequencies of each mutation were included, exon 5 comprised 61% (65 chromosomes) of the mutations; in Scandinavian patients the frequency of these mutations was 72%. Thus, analysis of exon five in these patients enables both reliable and time-saving first screening in prenatal diagnostic cases. This could be followed by a second step of additional strategies for the detection of other mutations.     

Identification of variants in NFKBIA and association analysis with hepatocellular carcinoma risk among chronic HBV patients

Human nuclear factor of kappa light chain gene enhancer in B cells inhibitor, alpha (NFKBIA) inhibits the action of NF-kappaB by forming a heterodimer with NF-kappaB, and preventing its translocation to the nucleus. We have sequenced a human NFKBIA full gene including -1000bp promoter region to identify its gene polymorphisms as a potential candidate gene for host genetic study of Hepatocellular Carcinoma (HCC). Nine novel single nucleotide polymorphisms (SNPs) and one GAA deletion were identified; two in promoter region (c.-673A>T, c.-642C>T), two in exon 1 (c.78G>A (Leu26Leu), c.81C>T (Asp27Asp)), three in introns (c.284T>A, c.1952A>G and c.2444C>T) and three in 3'UTR (c.2710-2712delGAA, c.2758G>A and c.3053G>A). Among ten identified variants, six were selected for larger scale genotyping (n=1,750) for association study based on frequencies and location. Haplotypes, their frequencies and linkage disequilibrium coefficients (/D'/) between SNP pairs were estimated. Allele frequencies of each SNPs and haplotypes were compared between patients with HCC and patients without HCC among HbsAg positives by logistic regression. As a conclusion, we could not find any significant association of NFKBIA variants with development of HCC among chronic hepatitis B patients.     

Novel RS1 mutations associated with X-linked juvenile retinoschisis

To identify mutations in the retinoschisin (RS1) gene in families with X-linked retinoschisis (XLRS). Twenty families with XLRS were enrolled in this study. All six coding exons and adjacent intronic regions of RS1 were amplified by polymerase chain reaction (PCR). The nucleotide sequences of the amplicons were determined by Sanger sequencing. Ten hemizygous mutations in RS1 were detected in patients from 14 of the 20 families. Four of the ten mutations were novel, including c:176G>A (p:Cys59Tyr) in exon?3, c:531T>G (p:Tyr177X), c:607C>G (p:Pro203Ala) and c:668G>A (p:Cys223Tyr) in exon?6. These four novel mutations were not present in 176 normal individuals. The remaining six were recurrent mutations, including c:214G>A (p:Glu72Lys), c:304C>T (p:Arg102Trp), c:436G>A (p:Glu146Lys), c:544C>T (p:Arg182Cys), c:599G>A (p:Arg200His) and c:644A>T (p:Glu215Val). Our study expanded the mutation spectrum of RS1 and enriches our understanding of the molecular basis of XLRS.     

Molecular analysis of ARSA and PSAP genes in twenty-one Italian patients with metachromatic leukodystrophy: identification and functional characterization of 11 novel ARSA alleles

Metachromatic leukodystrophy (MLD), the demyelinating disorder resulting from impaired sulfatide catabolism, is caused by allelic mutations of the Arylsulfatase A (ARSA) locus except for extremely rare cases of Saposin-B (Sap-B) deficiency. We characterized twenty-one unrelated Italian patients among which seventeen were due to ARSA activity deficiency and 4 others resulted from Saposin-B defect. Overall, we found 20 different mutant ARSA alleles and 2 different Sap-B alleles. The eleven new ARSA alleles (c.53C>A; c.88G>C; c.372G>A; c.409_411delCCC; c.634G>C; [c.650G>A;c.1108C>T]; c.845A>G; c.906G>C; c.919G>T; c.1102-3C>G; c.1126T>A) were functionally characterized and the novel amino acid changes were also modelled into the three-dimensional structure. The present study is aimed at providing a broader picture of the molecular basis of MLD in the Italian population. It also emphasizes the importance of a comprehensive evaluation in MLD diagnosis including biochemical, enzymatic and molecular investigations.     

Sequence variations of the alpha-globin genes: scanning of high CG content genes with DHPLC and DG-DGGE

The alpha-globin chains are encoded by two duplicated genes (HBA2 and HBA1, 5'-3') showing overall sequence homology >96% and average CG content >60%. alpha-Thalassemia, the most prevalent worldwide autosomal recessive disorder, is a hereditary anemia caused by sequence variations of these genes in about 25% of carriers. We evaluated the overall sensitivity and suitability of DHPLC and DG-DGGE in scanning both the alpha-globin genes by carrying out a retrospective analysis of 19 variant alleles in 29 genotypes. The HBA2 alleles c.1A>G, c.79G>A, and c.281T>G, and the HBA1 allele c.475C>A were new. Three pathogenic sequence variations were associated in cis with nonpathogenic variations in all families studied; they were the HBA2 variation c.2T>C associated with c.-24C>G, and the HBA2 variations c.391G>C and c.427T>C, both associated with c.565G>A. We set up original experimental conditions for DHPLC and DG-DGGE and analyzed 10 normal subjects, 46 heterozygotes, seven homozygotes, seven compound heterozygotes, and six compound heterozygotes for a hybrid gene. Both the methodologies gave reproducible results and no false-positive was detected. DHPLC showed 100% sensitivity and DG-DGGE nearly 90%. About 100% of the sequence from the cap site to the polyA addition site could be scanned by DHPLC, about 87% by DG-DGGE. It is noteworthy that the three most common pathogenic sequence variations (HBA2 alleles c.2T>C, c.95+2_95+6del, and c.523A>G) were unambiguously detected by both the methodologies. Genotype diagnosis must be confirmed with PCR sequencing of single amplicons or with an allele-specific method. This study can be helpful for scanning genes with high CG content and offers a model suitable for duplicated genes with high homology.     

Identification of the bruton tyrosine kinase (BTK) gene mutations in 20 Australian families with X-linked agammaglobulinemia (XLA)

X-linked agammaglobulinemia (XLA) is an immunodeficiency caused by mutations in the Bruton tyrosine kinase (BTK) gene. Twenty Australian patients with an XLA phenotype, from 15 unrelated families, were found to have 14 mutations. Five of the mutations were previously described c.83G>A (p.R28H), c.862C>T (p.R288W), c.904G>A (p.R302G), c.1535T>C (p.L512P), c.700C>T (p.Q234X), while nine novel mutations were identified: four missense c.82C>A (p.R28S), c.494G>A (p.C165Y), c.464G>A (p.C155Y), c.1750G>A (p.G584E), one deletion c.142_144delAGAAGA (p.R48_G50del), and four splice site mutations c.241-2A>G, c.839+4A>G, c.1350-2A>G, c.1566+1G>A. Carrier analysis was performed in 10 mothers and 11 female relatives. The results of this study further support the notion that molecular genetic testing represents an important tool for definitive and early diagnosis of XLA and may allow accurate carrier status and prenatal diagnosis.     

Functional analysis of 13 GBA mutant alleles identified in Gaucher disease patients: Pathogenic changes and "modifier" polymorphisms

Gaucher disease, the most prevalent sphingolipidosis, is caused by the deficient activity of acid beta-glucosidase, mainly due to mutations in the GBA gene. Over 200 mutations have been identified worldwide, more than 25 of which were in Spanish patients. In order to demonstrate causality for Gaucher disease, some of them: c.662C>T (p.P182L), c.680A>G (p.N188S), c.886C>T (p.R257X), c.1054T>C (p.Y313H), c.1093G>A (p.E326K), c.1289C>T (p.P391L), c.1292A>T (p.N392I), c.1322T>C (p.I402T), and the double mutants [c.680A>G; c.1093G>A] ([p.N188S; p.E326K]) and [c.1448T>C; c.1093G>A] ([p.L444P; p.E326K]), were expressed in Sf9 cells using a baculovirus expression system. Other well-established Gaucher disease mutations, namely c.1226A>G (p.N370S), c.1342G>C (p.D409H), and c.1448T>C (p.L444P), were also expressed for comparison. The levels of residual acid beta-glucosidase activity of the mutant enzymes produced by the cDNAs carrying alleles c.662C>T (p.P182L), c.886C>T (p.R257X), c.1054T>C (p.Y313H), c.1289C>T (p.P391L), and c.1292A>T (p.N392I) were negligible. The c.1226A>G (p.N370S), c.1322T>C (p.I402T), c.1342G>C (p.D409H), c.1448T>C (p.L444P), and [c.1448T>C; c.1093G>A] ([p.L444P; p.E326K]) alleles produced enzymes with levels ranging from 6 to 14% of the wild-type. The three remaining alleles, c.680A>G (p.N188S), c.1093G>A (p.E326K), and [c.680A>G; c.1093G>A] ([p.N188S; p.E326K]), showed higher activity (66.6, 42.7, and 23.2%, respectively). Expression studies revealed that the c.1093G>A (p.E326K) change, which was never found alone in a Gaucher disease-causing allele, when found in a double mutant such as [c.680A>G; c.1093G>A] ([p.N188S; p.E326K]) and [c.1448T>C; c.1093G>A] ([p.L444P; p.E326K]), decreases activity compared to the activity found for the other mutation alone. These results suggest that c.1093G>A (p.E326K) should be considered a "modifier variant" rather than a neutral polymorphism, as previously considered. Mutation c.680A>G (p.N188S), which produces a mutant enzyme with the highest level of activity, is probably a very mild mutation or another "modifier variant."     

USH2A mutation analysis in 70 Dutch families with Usher syndrome type II

Usher syndrome type II (USH2) is characterised by moderate to severe high-frequency hearing impairment, progressive visual loss due to retinitis pigmentosa and intact vestibular responses. Three loci are known for USH2, however, only the gene for USH2a (USH2A) has been identified. Mutation analysis of USH2A was performed in 70 Dutch USH2 families. Ten mutations in USH2A were detected, of which three are novel, c.949C>A, c.2242C>T (p.Gln748X) and c.4405C>T (p.Gln1468X). Including 9 previously published Dutch USH2a families, estimates of the prevalence of USH2a in the Dutch USH2 population were made. Mutations were identified in 62% of the families. In 28% both mutated alleles were identified, whereas in 34% the mutation in only one allele was found. It is estimated that about 28% of the Dutch USH2 families have a different causative gene. Analysis of deduced haplotypes suggests that c.1256G>T (p.Cys419Phe) is a Dutch ancestral mutation, occurring in 16% of the alleles.     

Novel L2HGDH mutations in 21 patients with L-2-hydroxyglutaric aciduria of Portuguese origin

We studied 21 patients, from 18 families, with L-2-hydroxyglutaric aciduria (L-2-HGA), a rare neurometabolic disorder with a homogeneous presentation: progressive neurodegeneration with extrapyramidal and cerebellar signs, seizures, and subcortical leukoencephalopathy. Increased levels of L-2-hydroxyglutaric acid in body fluids proved the diagnosis of L-2-HGA in all 21 patients. We analyzed the L-2-HGA gene (L2HGDH), recently found to be mutated in consanguineous families with L-2-HGA, and identified seven novel mutations in 15 families. Three mutations appeared to be particularly prevalent in this Portuguese panel: a frameshift mutation (c.529delC) was detected in 12 out of 30 mutant alleles (40%), a nonsense mutation (c.208C>T; p.Arg70X) in 7/30 alleles (23%), and a missense mutation (c.293A>G; p.His98Arg) in four out of 30 mutant alleles (13%), suggesting that common origin may exist. Furthermore, two novel missense (c.169G>A; p.Gly57Arg, c.1301A>C; p.His434Pro) and two splice error (c.257-2A>G, c.907-2A>G) mutations were found. All the mutations presumably lead to loss-of-function with no relationship between clinical signs, progression of the disease, levels of L-2-HGA and site of the mutation. In the three remaining families, no pathogenic mutations in the L-2-HGA were found, which suggests either alterations in regulatory regions of the gene or of its intervening sequences, compound heterozygosity for large genomic deletion and, or further genetic heterogeneity.     

Low frequency of deafness-associated GJB2 variants in Kenya and Sudan and novel GJB2 variants

A large proportion of non-syndromic autosomal recessive deafness (NSARD) in many populations is caused by variants of the GJB2 gene. Here, the frequency of GJB2 variants was studied in 406 and 183 apparently unrelated children from Kenya and Sudan, respectively, with mostly severe to profound non-syndromic deafness. Nine (2.2 %) Kenyan and 12 (6.6 %) of the Sudanese children only were carriers of variants within the coding sequence of the GJB2 gene. Variants in the 5'-adjacent region were detected in further 115 individuals. A total of 10 novel variants was recognized, among them four variants in the adjacent 5'-region of the GJB2 coding exon 2 (g.3318-6T>A, g.3318-15C>T, g.3318-34C>T, g.3318-35T>G), a 6 base-pair deletion (g.3455_3460del [p.Asp46_Gln48delinsGlu]), a variant leading to a stop codon (g.3512C>A [p.Tyr65X]), synonymous variants (g.3395C>T [p.Thr26], g.3503C>T [p.Asn62], g.3627A>C [p.Arg104]), and one non-synonymous variant (g.3816C>A [p.Val167Met]). In addition, the previously described variants g.3352delG (commonly designated 30delG or 35 delG), g.3426G>A [p.Val37Ile], g.3697G>A [p.Arg127His], g.3774G>A [p.Val153Ile], and g.3795G>A [p.Gly160Ser] were identified. With the exception of g.3318-34C>T and g.3352delG, all variants occurred heterozygously. For most of the variants identified in the Kenyan and Sudanese study population, a causative association with NSARD appears to be unlikely. Compared to many other ethnic groups, deafness-associated variants of the coding region of GJB2 are rare in Sudan and Kenya, suggesting a role of other genetic, or epigenetic factors as a cause for deafness in these countries.     

Mucopolysaccharidosis I mutations in Chinese patients: identification of 27 novel mutations and 6 cases involving prenatal diagnosis

Mucopolysaccharidosis I (MPS I) is a lysosomal storage disease that results from the deficiency of α-l-iduronidase and is transmitted in an autosomally recessive manner. This report describes the first systematic screening for mutations in Chinese MPS I patients from mainland China, wherein we have summarized the phenotype/genotype correlation of the individuals in Chinese MPS I patients. Mutational analyses were performed in 57 unrelated Chinese MPS I patients. Overall, 105 mutant alleles were identified from a set of 41 different mutations. Notably, of these 41 mutations, 27 were novel mutations that consisted of 8 splicing mutations (c.1-2C>G, c.296+4G>A, c.300-1G>C, c.792+1G>C, c.973-4G>A, c.1189+5G>T, c.1402+1G>T and c.1402+2T>G), 1 nonsense mutation (p.W41X), 1 insertion (c.668-670ins GCG), 5 duplications (c.531dupT, c.657dupG, c.883dupC, c.1147dupG and c.1225dupG), 3 deletions (c.349delT, c.1593delG and c.1244-1271del27),1 nucleotide substitution c.2T>C and 8 missense mutations (p.H33P,p.F52L, p.G168V,p.T179R,p. E182D, p.L237R, p.L238R and p.L421P). The missense mutations p.A79V and p.L346R, which accounted for 16.7% (19/114) and 12.3% (14/114) respectively, were the common mutations in Chinese patients but were rare in the mutational profiles reported for other populations. These results indicate that Chinese MPS I patients may have a different mutational spectrum compared to those of other populations. Moreover, for the first time in China, molecular genetic methods were used for prenatal diagnosis of six cases in five families.     

Six novel alleles identified in Italian hereditary fructose intolerance patients enlarge the mutation spectrum of the aldolase B gene

Hereditary fructose intolerance (HFI) is a recessively inherited disorder of carbohydrate metabolism caused by impaired functioning of human liver aldolase (B isoform; ALDOB). To-date, 29 enzyme-impairing mutations have been identified in the aldolase B gene. Here we report six novel HFI single nucleotide changes identified by sequence analysis in the aldolase B gene. Three of these are missense mutations (g.6846T>C, g.10236G>T, g.10258T>C), one is a nonsense mutation (g.8187C>T) and two affect splicing sites (g.8180G>C and g.10196A>G). We have expressed in bacterial cells the recombinant proteins corresponding to the g.6846T>C (p.I74T), g.10236G>T (p.V222F), and g.10258T>C (p.L229P) natural mutants to study their effect on aldolase B function and structure. All the new variants were insoluble; molecular graphics data suggest this is due to impaired folding.     

Identification of four novel polymorphisms in the calcitonin/alpha-CGRP (CALCA) gene and an investigation of their possible associations with Parkinson disease, schizophrenia, and manic depression

We identified novel polymorphisms in the calcitonin/CGRPalpha (CALCA) gene by direct sequencing of genomic DNA and subsequent genotyping by RFLP (restriction fragment length polymorphism) detection and investigated association with neurological or psychiatric disease. Four novel polymorphic alleles were found: two (g.979G>A and g.4218T>C) represented single nucleotide polymorphisms (SNPs), one consisted of two coupled SNPs in close vicinity to each other (g.1210T>C and g.1214C>G), and one was an intronic 16-bp microdeletion (2919-2934del16). One of the SNPs (g.4218T>C) causes a non-synonymous amino acid change (Leu66Pro) in the third exon, an exon common to both procalcitonin and pro-alpha-CGRP. In a subsequent association study, frequencies of the identified polymorphisms in Parkinson and schizophrenia patients were compared with frequencies in the normal population. No statistically significant association was found in our material. The 16-bp microdeletion polymorphism was present in a family with multiple cases of unipolar or bipolar depressive disorder. Using this polymorphism as marker, cosegregation with the phenotype was observed in the majority of individuals.     

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.