Mutation spectrum of the PCCA and PCCB genes in Japanese patients with propionic acidemia

Propionic acidemia (PA) is an inborn error of organic acid metabolism caused by a deficiency of propionyl-CoA carboxylase. This enzyme is composed of two non-identical subunits, alpha and beta, which are encoded by the PCCA and PCCB genes, respectively. An enzyme deficiency can result from mutations in either PCCA or PCCB. To elucidate the mutation spectrum in Japanese patients, we have performed a mutation analysis of 30 patients with PA, which included nine previously reported patients. The study revealed that 15 patients were alpha-subunit deficient and 15 patients were beta-subunit deficient. Seven novel mutations were found (IVS18-6C >G, 1746G >A, C398R, G197E and IVS18+1G >A in the PCCA; A153P and IVS9+1G >T in the PCCB). Among these Japanese patients with alpha-subunit deficiencies, 923-924insT, IVS18-6C >G, and R399Q mutations were frequent and the total allelic frequency of these three mutations combined was 56% (17/30). This is in sharp contrast to the mutation spectrum found in Caucasian patients, where no prevalent mutations have been identified. Among the beta-subunit deficiencies, there were three frequent mutations; R410W, T428I, and A153P, whose allelic frequencies were 30, 26.7, and 13.3%, respectively. In conclusion, a limited number of mutations are predominant in both PCCA and PCCB genes among Japanese patients with propionic acidemia.     

FcRL3基因三个单核苷酸多态性与重庆汉族人群Graves病关联研究

目的 了解中国重庆地区汉族人群Fc受体样因子(Fc receptor-like proteins,FcRL3)基因启动子A/G,第2外显子C/G,第4外显子C/T多态性与Graves病(Graves disease,GD)的相关性.方法 采用聚合酶链反应限制性片段长度多态性分析方法结合直接测序技术,对重庆地区无亲缘关系的120名正常人和128例GD患者进行多态性研究,同时进行甲状腺功能和自身抗体的检测,应用Unphased1122和LDA1.0软件进行连锁不平衡和单倍型分析,用卡方检验分析基因型、等位基因和单倍型频率在GD组和对照组之间的差异.结果 GD组FcRL3基因3个多态性位点基因型和等位基因的频率与对照组相比,其差异均有统计学意义(P＜0.05).连锁不平衡分析显示启动子和第2外显子存在连锁不平衡,在构建的3个主要单倍型中,仅H2(G-G)单倍型频率GD组明显高于对照组(50.8%vs 35.8%,P＜0.05).除甲状腺疾病家族史与启动子多态性有关联(P%0.05),余临床特征与FcRL3多态性均无相关.结论 多个位点及单倍型分析提示FcRL3基因启动子A/G,第2外显子C/G,第4外显子C/T多态性可能是中国重庆地区汉族人群GD关联的危险因素.     

Cathepsin K gene mutations and 1q21 haplotypes in at patients with pycnodysostosis in an outbred population

The molecular genetics of the autosomal recessive disorder pycnodysostosis was studied in five independent families from an outbred Caucasian population. We found two new mutations and one recently described mutation in the cathepsin K gene by sequencing DNA from eight patients with pycnodysostosis: a one base transition in exon8, c926T > C, causing a single amino acid substitution leucine-->proline, L309P; A 3' splice site mutation in intron 2, c121-1G > A, causing deletion of all exon 3, 41V-81Mdel; and the exon 3 missense mutation c236G > A leading to residue G79E. In three of the families patients were homozygous for 926T > C. In the remaining two families patients were heterozygous for 926T > C and 121-1G > A in one case, and for 926T > C and 236G > A in the other case. Assays using genomic DNA were developed for all three mutations. We tested 150 healthy control persons and observed the mutation frequencies: 0 to 300 for 121-1G > A and 236G > A and 1 to 150 for 926T > C. One patient from each family was haplotyped with eight microsatellite markers surrounding the cathepsin K gene on chromosome 1q21. A very rare, P = 1.8 x 10(-6) to P = 0.0004, and highly preserved area around the presumed disease locus was common to all the patients. This haplotype was found on seven chromosomes identical by state, IBS, out of the possible eight carrying the 926T > C mutation. Founder effect, locus homogeneity, and allele heterogeneity regarding pycnodysostosis within this population are discussed. Finally, the first pregnancy and delivery described in a patient with pycnodysostosis is reported.     

Association between nonsyndromic cleft lip with or without cleft palate and the glutamic acid decarboxylase 67 gene in the Japanese population

Nonsyndromic cleft lip with or without cleft palate (NSCLP) is one of the most common craniofacial malformations. Both genetic and environmental factors are involved in the pathogenesis. In addition to its role as an inhibitory neurotransmitter, gamma-aminobutyric acid (GABA) synthesized by glutamic acid decarboxylase (GAD) is presumed to play a role in normal embryonic, especially facial, development. This notion has been substantiated by the fact that Gad67 knockout mice have been shown to have cleft palate. We hypothesized that GAD67 may be involved in the development of NSCLP and investigated the possible association between the GAD67 gene (GAD67) and NSCLP in Japanese patients. We screened 50 probands for single nucleotide polymorphisms (SNPs) in GAD67 using denaturing high performance liquid chromatography (DHPLC) and found seven SNPs. Since two SNPs showed complete linkage disequilibrium (LD) to the other SNPs, we constructed a 5-locus haplotype of GAD67. The frequency distribution of the haplotype differed between NSCLP patients and controls (P = 0.0028). The frequency of -445A, -292A, -147G, 111C, and IVS9-39T haplotype in the NSCLP patients was significantly lower than that in controls (P = 0.00098). In a transmission disequilibrium test (TDT) in 99 parent-offspring trios, we found -445C, -292C, -147G, 111C, and IVS9-39C haplotype was preferentially transmitted to the patients with cleft lip and palate (P = 0.0077). Our data suggest that GAD67 is involved in the pathogenesis of NSCLP in the Japanese population.     

Microsomal epoxide hydrolase genotypes and chronic obstructive pulmonary disease in Japanese

Polymorphisms in the gene for microsomal epoxide hydrolase (mEPHX), an enzyme involved in the protective mechanism against oxidative stress, have been reported to be associated with individual susceptibility to the development of chronic obstructive pulmonary disease (COPD). The polymorphisms in exons 3 and 4 in the mEPHX gene were examined in a total of 358 Japanese individuals, including 40 patients with COPD and 71 patients with lung cancer. The overall frequencies of variant allele for mEPHX codons 113 (exon 3) and 139 (exon 4) were 44% and 14%, respectively. Moreover, a novel single nucleotide polymorphism (estimated allele frequency: 0.29) was identified in Japanese at 20 bp downstream of the codon 113 polymorphism with strong linkage disequilibrium with the wild allele for codon 113. While the frequencies of variant allele and proportions of individuals homozygous variant for codon 113, assumed having very slow mEPHX activity, were similar among COPD or lung cancer patients and the control population, they were significantly higher in patients with severe COPD than in those with mild COPD [P=0.0225, odds ratio 2.9 (95%CI 1.1-7.4); P=0.0350, respectively]. Thus, we found that the frequency of the variant allele for mEPHX codon 113 is higher in Japanese than that in Caucasians (P=0.0028), a novel silent polymorphism exists in exon 3 and shows strong linkage disequilibrium with the wild allele for codon 113, and individual homozygous variants for codon 113 may be associated with development of advanced COPD rather than the susceptibility to COPD.     

The major allele of the alanine:glyoxylate aminotransferase gene: nine novel mutations and polymorphisms associated with primary hyperoxaluria type 1

We describe nine novel mutations and polymorphisms occurring on the major allele of the human alanine:glyoxylate aminotransferase gene in patients with primary hyperoxaluria type 1, an autosomal recessive disease resulting from a deficiency of the liver peroxisomal enzyme alanine:glyoxylate aminotransferase (AGT; EC 2.6.1.44). The PH1 mutations include two small frameshift mutations, 327delG and 117_118insCA, a large deletion spanning exon 9 and portions of the flanking introns, a splice junction mutation, IVS6+5G>C, and two missense mutations, G161R and S218L. Expression studies of the two missense mutations indicated very little enzymatic activity associated with either of them. Three polymorphisms in the coding sequence were also identified, I279T, A280V, and T235T. Expression studies of I279T and A280V suggested essentially normal AGT activity. I279T, found in two cases, was located on a 33_34insC allele. A280V and T235T were both located on the same allele as IVS6+5G>C. We have also identified recurrences of previously reported rare mutations, 33delC, IVS7-1G>C, and IVS4-1G>A. Five of the six novel PH1 mutations occurred in a compound heterozygous state with either of two common PH1 mutations, G170R or 33_34insC. S218L was apparently homozygous in two individuals. These findings contribute to our overall picture of heterogeneity of mutations in PH1 and the AGT major allele.     

Three novel PAX6 mutations in patients with aniridia.

AIMS: To describe mutations in the PAX6 gene in five patients with aniridia from three unrelated families. METHODS: The PAX6 gene was analysed using single stranded conformational polymorphism analysis and direct sequencing. RESULTS: In one family, three individuals from two generations had aniridia, whereas in each of the other families only one member was affected. The first patient had the heterozygous Q221X (1023C --> T) nonsense mutation in exon 8. The same mutation was found in his mother and sister. Another patient had a heterozygous Q297X (1252C --> T) mutation in exon 10. The third patient carried a heterozygous IVS5+2T --> C mutation leading to aberrant splicing of mRNA. CONCLUSIONS: These findings provide further examples of haploinsufficiency of PAX6 in aniridia.     

纤维蛋白原Bβ基因启动区单核苷酸多态性及连锁不平衡分析

目的　探讨纤维蛋白原 B(fibrinogen,FGB)基因启动区 - 14 8C/ T、- 4 5 5 G/ A、- 85 4 G/ A3个位点单核苷酸多态性 (single nucleotide polymorphism,SNP)在中国南方汉族人群的分布特征及连锁不平衡关系。方法　应用聚合酶链反应 -限制性片段长度多态性技术结合 DNA测序分析检测 377名中国南方汉族人 FGBβ基因型和等位基因的分布频率 ,群体数理遗传学方法分析 FGBβ 3个基因位点 SNP的遗传平衡吻合度和相互间连锁不平衡关系。结果　 3个 FGBβ SNP位点等位基因频率分布符合 Hardy-Weinberg平衡。检出了 FGBβ3个位点 SNP的共 9种基因型 ,- 14 8CC、CT、TT基因型频率分别为0 .5 97、0 .35 8和 0 .0 4 5 ;- 4 5 5 G/ A SNP各基因型频率与 - 14 8C/ T SNP相同 ;- 85 4 GG、GA、AA基因型频率分别为 0 .82 0、0 .178和 0 .0 0 2。各 SNP位点的少见型等位基因频率分别是 0 .2 2 4 (- 14 8T)、0 .2 2 4 (-4 5 5 A)、0 .0 92 (- 85 4 A) ;常见型等位基因频率分别为 0 .776 (- 14 8C)、0 .776 (- 4 5 5 G)、0 .90 8(- 85 4 G)。男女性别间各基因型和等位基因分布频率差异无显著性 (P>0 .0 5 )。经连锁不平衡检验 ,- 14 8C与 - 4 5 5 GSNP为完全一致型 ,- 85 4 G/ A与 - 14 8C/ T、- 4 5 5 G/ A为随机分布。结     

Glucose and lipid metabolism in relation to novel polymorphisms in the 5'-AMP-activated protein kinase gamma2 gene in Chinese

The 5'-AMP-activated protein kinase (AMPK) behaves as a fuel sensor in glucose and lipid metabolism. We sequenced exon 1 and flanking regions of the gene encoding for the gamma2 subunit of AMPK (AMPKgamma2) and identified two novel common polymorphisms at position -26 and IVS1+43. We then studied these two polymorphisms in relation to plasma glucose, insulin resistance, beta-cell function, and serum lipids in 290 Han Chinese undergoing an oral glucose tolerance test and a frequently sampled intravenous glucose tolerance test. The -26C/T and IVS1+43C/T polymorphisms were in tight linkage disequilibrium (P=0.0002). In adjusted categorical analyses, the -26TT genotype tended to be associated with a higher risk of type 2 diabetes (odds ratio 4.52, P=0.07). The adjusted continuous analyses were confirmatory. -26TT subjects, compared with -26C allele carriers, had higher concentrations of plasma glucose, both fasting (7.3 vs. 6.1 mmol/L, P=0.02) and after oral glucose loading (area under the curve for glucose, 1984 vs. 1596 minmmol/L, P=0.002), and had lower acute insulin response to glucose (143 vs. 404, P=0.0005) and disposition index (151 vs. 459, P=0.008). In further adjusted analyses, we observed that IVS1+43TT subjects, compared with IVS1+43C allele carriers, had significantly higher serum concentrations of triglycerides (4.20 vs. 2.00 mmol/L, P<0.0001) and total cholesterol (5.88 vs. 4.99 mmol/L, P=0.01). In conclusion, in Chinese, the AMPKgamma2 polymorphisms might be associated with glucose and lipid metabolism.     

SLC22A12基因第8外显子和第8内含子多态与中国汉族人原发性高尿酸血症关联研究

目的 研究原发性高尿酸血症患者SLC22AI2基因第8内含子和第8外显子单核苷酸多态(single nucleotide polymorphism,SNP)位点与原发性高尿酸血症遗传易感性的关系.方法 选择山东沿海地区原发性高尿酸血症患者215例,正常对照人群323名.提取基因组DNA,PCR扩增SLC22A12基因第8内含子和第8外显子,对PCR扩增产物进行测序.结果 序列分析发现:(1)SLC22AI2基因第8外显子存在T1309C单核苷酸多态,第8内含子存在-103A＞G单核苷酸多态,这2个多态位点完全连锁.(2)高尿酸血症组-103A＞G G等位基因频率和T1309C C等位基因频率明显高于正常对照组(均为51.9%vs.42.4%,P＜0.01);(3)高尿酸血症组GG+GA基因型频率和CC+CT基因型频率显著高于正常对照组(均为80.0%vs.69.0%,P＜0.01).(4)-103 A＞G和T1309C基因多态中,含有等位基因G的基因型GG+GA及含有等位基因C的基因型CC+CT均使高尿酸血症的发病危险性上升了1.79倍(OR=1.79,95%CI:1.19～2.70).结论 SLC22A12基因第8外显子T130gC及第8内含子-103A＞G SNP与原发性高尿酸血症密切相关.     

Allelic homogeneity in Avellino corneal dystrophy due to a founder effect

Avellino corneal dystrophy (ACD) is a common corneal dystrophy that shows allelic homogeneity, R124H mutation in the transforming growth factor beta-induced (TGFBI) gene. There are distinct phenotypes of homozygous Avellino corneal dystrophy, termed types I and II. To investigate if the difference is caused by a modifier mutation, we sequenced the entire coding region of TGFBI of two types of ACDs. The sequences obtained from each type were identical, and we could not find any nucleotide alternations. Instead, we found seven single nucleotide polymorphisms (SNPs) compared with the normal control. Primer extension analysis revealed that all 14 homozygous patients were homozygotes in each SNP, which meant that all the patients shared the same disease haplotype. Subsequent analysis of 45 heterozygous ACD patients showed strong linkage disequilibrium between disease alleles of each SNP and ACD. These results strongly suggest that the allelic homogeneity of TGFBI associated corneal dystrophies (ACD, lattice corneal dystrophy types I and III, granular corneal dystrophy and Reis–Bucklers dystrophy) might not be caused by mutation hot spots but by the founder effects.     

Mutation analysis of the calpastatin gene (CAST) in patients with Alzheimer's disease

The calpains, a family of calcium-dependent cysteine proteinases, and calpastatin, their endogenous inhibitor protein, are involved in the proteolysis of amyloid precursor protein, which is thought to be abnormal in patients with Alzheimer's disease (AD). Specific inhibitors of calpains attenuate amyloid beta peptide-induced neuronal death. We hypothesized that some AD patients have functionally deficient mutation(s) of the CAST gene encoding calpastatin, and we screened 40 Japanese patients with AD for mutations in the coding region of CAST. Nine polymorphisms, -82A/G, IVS7-96A/G, 669A/G, 1223C/G (Ser408Cys), IVS20-10C/T, IVS21-65G/A, IVS22+31T/C, IVS24+38Ins/DelA, and IVS25-32A/G, were identified. The 669A allele causes skipping of exon 11, leading to the loss of 13 residues. Comparisons between 101 patients and 90 controls revealed no significant association between CAST polymorphisms and risk for AD, indicating that genomic variations of CAST are not likely to be substantially involved in the etiology of AD.     

Significant association between nonsyndromic oral clefts and arylhydrocarbon receptor nuclear translocator (ARNT)

The etiology of nonsyndromic oral clefts (cleft lip, cleft palate, or cleft lip and palate) is still controversial, but is considered to involve both genetic and environmental factors. One of suspected environmental factors is 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) found in tobacco, herbicides, contaminated soil, and food. TCDD administered during organogenesis in mice causes a high incidence of CP in fetuses. There is ample evidence that aryl hydrocarbon receptor (AHR), AHR nuclear translocator (ARNT), and cytochrome P450 1A1 (CYP1A1) are involved in TCDD metabolism. We assessed whether there is any association in the Japanese population of nonsyndromic oral clefts with single nucleotide polymorphisms (SNPs) in the AHR, ARNT, and CYP1A1 genes using transmission disequilibrium test (TDT) and case-control study. We identified and investigated three SNPs in ARNT; 567G/C (V189V), IVS12-19T/G, and 2117C/T (P706L). Two amino acid substitutions, R554L in AHR and I462V in CYP1A1, were also investigated. In the TDT, the C allele of ARNT 567G/C was preferentially transmitted to patients (P = 0.033). When a haplotype consisting of 567G/C and IVS12-19T/G in ARNT was considered, the preferential transmission of the CT (567C-IVS12-19T) haplotype was observed (P = 0.0012). In a case-control study, a significant association of IVS12-19T/G in ARNT was observed (P = 0.021). The SNPs studied in AHR and CYP1A1 were not associated with the disease. Our results suggest that ARNT is involved in the development of nonsyndromic oral clefts in the Japanese population.     

No genetic association between Fyn kinase gene polymorphisms (-93A/G, IVS10+37T/C and Ex12+894T/G) and Japanese sporadic Alzheimer's disease

Several groups have reported that abnormal phosphorylation of tau by Fyn, a protein-tyrosine kinase, may play a role in the neuropathogenesis of Alzheimer's disease (AD). In the present study, three common Japanese polymorphisms of the Fyn gene (-93A/G in the 5'-flanking region, IVS10+37T/C in intron 10 and Ex12+894T/G in the 3'-untranslated region) were studied in 127 healthy controls and 182 sporadic AD cases using a polymerase chain reaction restriction fragment length polymorphism method. A comparison of the allelic and genotypic frequencies of these polymorphisms between controls and sporadic AD cases failed to show any significant difference. These results suggest that the Fyn polymorphisms (-93A/G, IVS10+37T/C and Ex12+894T/G) investigated here have no genetic association with sporadic AD.     

PAX9 and TGFB3 are linked to susceptibility to nonsyndromic cleft lip with or without cleft palate in the Japanese: population-based and family-based candidate gene analyses

The prevalence of nonsyndromic cleft lip with or without cleft palate (CL/P) and cleft palate only (CPO) are believed to be higher in the Japanese than in Americans, Europeans or Africans. The purpose of this study was to investigate, in a Japanese population, relationships between CL/P or CPO and seven candidate genes (TGFB3, DLX3, PAX9, CLPTM1, TBX10, PVRL1, TBX22) that showed positive associations in other populations and are expressed in the oral/lip region in developing mice. We first searched for mutations in these genes among 112 CL/P and 16 CPO patients, and found a heterozygous missense mutation (640A>G, S214G) in exon 3 of PAX9 in two sibs with CL/P and their phenotypically normal mother from a Japanese family. A population-based case-control analysis and a family-based transmission disequilibrium test (TDT), using single nucleotide polymorphisms (SNPs), and two-SNP haplotypes of the genes, between the 112 CL/P cases with their parents and 192 controls indicated a significant association at one SNP site, IVS1+5321, in TGFB3 with a P-value of 0.0016. Population-based haplotyping revealed that the association was most significant for haplotype A/A consisting of IVS1+5321 and IVS1–1572; TDT also gave a P-value of 0.0252 in this haplotype.     

BRCA1 germline mutations in Indian familial breast cancer

Germline mutation analysis of BRCA1 gene has demonstrated significant allelic heterogeneity. These differences represent historical influences of migration, population structure and geographic or cultural isolation. To date, there have been no reports of Indian families with mutations in BRCA1. We have screened for mutations in selected coding exons of BRCA1 and their flanking intron regions in three breast or breast and ovarian cancer families with family history of three or more cases of breast cancer under age 45 and/or ovarian cancer at any age. We have also analyzed 10 female patients with sporadic breast cancer regardless of age and family history, as well as 50 unrelated normal individuals as controls. Thus a total of 90 samples were analyzed for BRCA1 mutations using polymerase chain reaction-mediated site directed mutagenesis (PSM) and single stranded conformation polymorphism (SSCP) analysis for various selected exons followed by sequencing of variant bands. Eight point mutations were identified. Two deleterious pathogenic, protein truncating non-sense mutations were detected in exon 11 (E1250X) and exon 20 (E1754X) and six novel and unique amino acid substitutions (F1734S, D1739Y, V1741G, Q1747H, P1749A, R1753K). One complex missense mutation of exon 20 [V1741G; P1749A] was seen in two out of three families and another complex combination of missense and non-sense mutations of the same exon [V1741G; E1754X] was observed in only one family. These complex mutations exist only in breast cancer families but not in control populations of women. Three splice site variants (IVS20+3A>C, IVS20+4A>T, IVS20+5A>T) and two intronic variants (IVS20+21_22insG, IVS20+21T>G) were also detected. In the group of 10 sporadic female patients no mutations were found.     

Identification of mutations of Bruton's tyrosine kinase gene (BTK) in Brazilian patients with X-linked agammaglobulinemia

Mutations in the Bruton tyrosine kinase (BTK) gene are responsible for X-linked agammaglobulinemia (XLA), which is characterized by recurrent bacterial infections, profound hypogammaglobulinemia, and decreased numbers of mature B cells in the peripheral blood. We evaluated 17 male Brazilian patients from 13 unrelated families who showed markedly reduced numbers of blood B cells and hypogammaglobulinemia. BTK gene analysis detected mutations in 10 of the 13 presumed XLA families. Seven mutations (Q196X, G613D, R28L, 251-273del, Q234X, H364P, and R13X) had been reported previously, whereas the remaining three mutations (M501T, IVS15+1G>C, and IVS14+1G>A) were novel. Mutation IVS15+1G>C occurred in a splice donor site and caused exons 15 and 16 to be skipped, and IVS14+1G>A might cause exon 14 to be skipped. Flow cytometry revealed deficient expression of BTK protein in 10 of the 13 families. This is the first report of the diagnosis of XLA by analysis of mutations of the BTK gene in Brazilian patients.     

The 894T allele of endothelial nitric oxide synthase gene is related to left ventricular mass in African Americans with high-normal blood pressure

BACKGROUND AND OBJECTIVES: The 894T allele in exon 7 of the endothelial nitric oxide synthase (eNOS) gene has been inconsistently associated with hypertension in different racial groups. Because high-normal blood pressure (BP) confers an increased risk for the development of hypertension and other cardiovascular disorders, including left ventricular hypertrophy (LVH), we tested the hypothesis that the allelic variation (894T) in the eNOS gene would directly correlate with alterations in LV mass (LVM) in individuals with high-normal BP. METHODS: Genotype distribution of G894T was compared between 20 African Americans (10 females/10 males) with high-normal BP (systolic BP of 130-139 and/or diastolic BP of 85-89 mmHg) and 64 counterparts (37 females/27 males) with normal BP (<130/85 mmHg). Echocardiographic LVM was calculated (Devereux formula) and indexed to body surface area to define the presence of LVH (LVMI >134/110 g/m2 for men/women). RESULTS: For the entire group, the 894T allelic frequencies (15, 48%) and G894T genotype distributions were consistent with the Hardy-Weinberg equilibrium expectations (estimated disequilibrium coefficient = 0.0118, P=0.40). LVMI was significantly higher in homozygous carriers (TT) of the rare 894T allele (n = 3 females/0 males) than in heterozygous GT (n = 13 females/7 males) and individuals bearing the GG (n=34 females/27 males) variant (124 +/- 70 vs. 82 +/- 24 and 82 +/- 19 g/m2, respectively, P < 0.05). The observed relationship between eNOS 894T allele and LVMI was restricted to individuals with high-normal BP (r = 0.94, P = 0.03) but not in those with normal BP (r = 0.39, P =0.64), by analysis of variance (ANOVA) after adjusting for age, gender, body mass index, smoking and systolic BP. CONCLUSION: These findings, not previously described, provide important preliminary evidence to suggest an increased susceptibility to LVH in African Americans who carry the 894T variant of the eNOS gene and have high-normal blood pressure.