RESUMEN
Trinidadians of South Asian origin have a high prevalence of cardiovascular disease and diabetes compared to Trinidadians of African origin. The degree to which these differences are related to genetic and/or environmental factors is unclear. To determine whether there might be a genetic basis for this difference in prevalence of deleterious phenotypes we examined allele frequencies for candidate genes in atherosclerosis and diabetes. We genotyped 81 consecutive neonates of African origin and 103 consecutive neonates of South Asian origin. We evaluated common polymorphisms in 11 candidate genes for atherosclerosis and diabetes. We found differences between the two subpopulations in the allele frequencies of several candidate genes, including APOE, LIPC, APOC3, PON1, PON2, and PPP1R3. However, the differences in the allele frequencies were not all consistent with the pattern of CHD expression between these two ethnic groups in adulthood. Thus, differences in genetic architecture alone may not explain the wide disparities in disease prevalence between these two subpopulations. It is very likely that environmental factors, or unmeasured genetic factors, influence the genetic susceptibility to disease in these subpopulations.
Asunto(s)
Arteriosclerosis/etnología , Arteriosclerosis/genética , Diabetes Mellitus Tipo 2/etnología , Diabetes Mellitus Tipo 2/genética , Frecuencia de los Genes/genética , Polimorfismo Genético/genética , África/etnología , Asia Sudoriental/etnología , Sangre Fetal , Marcadores Genéticos/genética , Predisposición Genética a la Enfermedad/genética , Humanos , Recién Nacido , Fenotipo , Prevalencia , Factores de Riesgo , Trinidad y Tobago/epidemiologíaRESUMEN
Pancreatic lipase (EC 3.1.1.3) is an exocrine secretion that hydrolyzes dietary triglycerides in the small intestine. We developed genomic amplification primers to sequence the 13 exons of PNLIP, which encodes pancreatic lipase, in order to screen for possible mutations in cell lines of four children with pancreatic lipase deficiency (OMIM 246600). We found no missense or nonsense mutations in these samples, but we found three silent single-nucleotide polymorphisms (SNPs), namely, 96A/C in exon 3, 486C/T in exon 6, and 1359C/T in exon 13. In 50 normolipidemic Caucasians, the PNLIP 96C and 486T alleles had frequencies of 0.083 and 0.150, respectively. The PNLIP 1359T allele was absent from Caucasian, Chinese, South Asian, and North American aboriginal samples, but had a frequency of 0.085 in an African sample, suggesting that it is a population-specific variant. In an association analysis of 185 African neonates, the PNLIP 1359C/T SNP genotype was significantly associated with concentrations of plasma lipoproteins. These associations were most likely due to linkage disequilibrium with another functional variant at or near PNLIP. Thus, we report three new SNPs for the PNLIP, which may serve as markers for association analyses and for pharmacogenetic studies of pancreatic lipase inhibitors.
Asunto(s)
Lipasa/genética , Lipasa/metabolismo , Páncreas/enzimología , Polimorfismo Genético , África/etnología , Secuencia de Bases , Línea Celular , Cartilla de ADN/genética , Humanos , Recién Nacido , Lipasa/deficiencia , Mutación , Polimorfismo de Nucleótido Simple , Trinidad y TobagoRESUMEN
Variation in the PON1 and PON2 genes has been shown to be associated with coronary heart disease risk in adults of South Asian origin. In this group, low birth weight is also associated with coronary heart disease risk. We therefore hypothesized that variation in PON1 and PON2 genes may be associated with variation in birth weight. This relationship was examined in 290 consecutive Trinidadian neonates of different ethnic origins. We found that variation in PON2 was significantly associated with variation in birth weight in Trinidadian neonates of South Asian origin. Among the neonates of South Asian origin, those who were homozygous for PON2 A148/A148 had significantly lower birth weight, by approximately 200 g, compared with those with the other two genotypes (P < 0.05). For neonates of South Asian origin, PON2 A148/A148 homozygotes were significantly more prevalent in those comprising the lowest tertile for birth weight than those comprising the highest tertile (0.41 versus 0.24, P < 0.05). There were no significant associations of PON2 variation with any phenotype in other ethnic groups. We conclude that among neonates of South Asian origin, homozygosity for PON2 A148/A148, is associated with significantly lower birth weight. This suggests that genetic factors in the fetus may be important determinants of neonatal birth weight and possibly of more distal adult phenotypes, such as coronary heart disease.
Asunto(s)
Arildialquilfosfatasa , Peso al Nacer/genética , Esterasas/genética , Adulto , Alelos , Asia/etnología , Enfermedad Coronaria/genética , Frecuencia de los Genes , Genotipo , Humanos , Recién Nacido , Desequilibrio de Ligamiento , Fenotipo , Trinidad y TobagoRESUMEN
OBJECTIVES: We hypothesized that common variation in the angiotensinogen (AGT), beta-3-adrenergic receptor. intestinal fatty acid-binding protein, serum paraoxonase, paraoxonase-2, hepatic lipase, apolipoprotein E (APOE), and Werner helicase (WRN) genes would be associated with variation in biochemical phenotypes in a previously unstudied neonatal sample. DESIGN AND METHODS: We examined associations of both nongenetic and genetic variables with plasma lipoprotein traits in neonates from Trinidad. RESULTS: Among nongenetic variables, we found significant associations between plasma concentrations of 1.) lipoprotein (a) [Lp(a)] and both ethnicity (p=0.037) and birth weight (p=0.001); 2)total cholesterol and gender (p=0.010); 3)triglyceride and birth weight (p=0.035); and 4)apolipoprotein A1 and gender (p=0.016). Among genetic variables, we found that: 1)common variation on chromosome 1q in AGT codon 235 was significantly associated with variation in plasma apolipoproteins Al (p<0.0001); and 3)common variation in APOE at codons 112 and 158 was significantly associated with variation in plasma triglycerides (p=0.013). CONCLUSIONS: The associations with AGT and WRN are novel and may have resulted either from direct influence of the genetic variants or through linkage disequilibrium with other functional loci, such as the familial combined hyperlipidemia locus on chromosome 1q in the case of AGT. Despite the fact that there are some limitations in making determinations from cord blood, the results suggest that there may be genetic determinants of plasma lipoproteins in neonates. (AU)
Asunto(s)
Lactante , Femenino , Humanos , Masculino , Lipoproteínas/sangre , Lipoproteínas/genética , África , Alelos , Angiotensinógeno/genética , Apolipoproteínas E/genética , Asia , Proteínas Portadoras/genética , ADN Helicasas/genética , Esterasas/sangre , Esterasas/genética , Frecuencia de los Genes , Genética de Población , Lipasa/genética , Proteína P2 de Mielina/genética , Fenotipo , Receptores Adrenérgicos beta/genética , Trinidad y Tobago/etnología , Variación GenéticaRESUMEN
Variation in the PON1 and PON2 genes has been shown to be associated with coronary heart disease risk in adults of South Asian origin. In this group, low birth weight is also associated with coronary heart disease risk. We therefore hypothesized that variation in PON1 and PON2 genes may be associated with variation in birth weight. This relationship was examined in 90 consecutive Trinidadian neonates of different ethnic origins. We found that variation in PON2 was significantly associated with variation in birth weight in Trinidadian neonates of south Asian origin. Among the neonates of South Asian origin, those who were homozygous for PON A148/A148 had significantly lower birth weight, by approximately 00 g, compared with those with the other two genotypes (P < 0.05). For neonates of south Asian origin, PON2 A148/A148 homozygotes were significantly more prevalent in those comprising the lowest tertile for birth weight than those comprising the highest tertile (0.41 versus 0.24, P < 0.05). There were no significant associations of PON variation with any phenotype in other ethnic groups. We conclude that among neonates of South Asian origin, homozygosity for PON2 A148/A148, is associated with significantly lower birth weight. This suggests that genetic factors in the fetus may be important determinants of neonatal birth weight and possibly of more distal adult phenotypes, such as coronary heart disease.(AU)
Asunto(s)
Adulto , Humanos , Recién Nacido , Peso al Nacer/genética , Esterasas/genética , Alelos , Asia/etnología , Enfermedad Coronaria/genética , Frecuencia de los Genes , Genotipo , Desequilibrio de Ligamiento , Fenotipo , Trinidad y TobagoRESUMEN
OBJECTIVES: We hypothesized that common variation in the angiotensinogen (AGT), beta-3-adrenergic receptor, intestinal fatty acid-binding protein, serum paraoxonase, paraoxonase-2, hepatic lipase, apolipoprotein E (APOE), and Werner helicase (WRN) genes would be associated with variation in biochemical phenotypes in a previously unstudied neonatal sample. DESIGN AND METHODS: We examined associations of both nongenetic and genetic variables with plasma lipoprotein traits in neonates from Trinidad. RESULTS: Among nongenetic variables, we found significant associations between plasma concentrations of: 1) lipoprotein(a) [Lp(a)] and both ethnicity (p = 0.037) and birth weight (p = 0.001); 2) total cholesterol and gender (p = 0.010); 3) triglyceride and birth weight (p = 0.035); and 4) apolipoprotein AI and gender (p = 0.016). Among genetic variables, we found that: 1) common variation on chromosome 1q in AGT codon 235 was significantly associated with variation in plasma apolipoproteins AI (p<0.0001) and B (p = 0.013); 2) common variation in WRN at codon 1367 was significantly associated with variation in plasma Lp(a) (p<0.0001); and 3) common variation in APOE at codons 112 and 158 was significantly associated with variation in plasma triglycerides (p = 0.013). CONCLUSIONS: The associations with AGT and WRN are novel and may have resulted either from a direct influence of the genetic variants or through linkage disequilibrium with other functional loci, such as the familial combined hyperlipidemia locus on chromosome 1q in the case of AGT. Despite the fact that there are some limitations in making determinations from cord blood, the results suggest that there may be genetic determinants of plasma lipoproteins in neonates.