RESUMO
<p><b>BACKGROUND</b>KCNJ11, ABCC8, PPARG, and HNF4A have been found to be associated with type 2 diabetes in populations with different genetic backgrounds. The aim of this study was to test, in a Chinese Han population from Beijing, whether the genetic variants in these four genes were associated with genetic predisposition to type 2 diabetes.</p><p><b>METHODS</b>We studied the association of four representative SNPs in KCNJ11, ABCC8, PPARG, and HNF4A by genotyping them using ABI SNaPshot Multiplex System in 400 unrelated type 2 diabetic patients and 400 unrelated normoglycaemic subjects.</p><p><b>RESULTS</b>rs5219 (E23K) in KCNJ11 was associated with genetic susceptibility to type 2 diabetes (OR = 1.400 with 95% CI 1.117 1.755, P = 0.004 under an additive model, OR = 1.652 with 95% CI 1.086 2.513, P = 0.019 under a recessive model, and OR = 1.521 with 95% CI 1.089 2.123, P = 0.014 under a dominant model) after adjusting for sex and body mass index (BMI). We did not find evidence of association for ABCC8 rs1799854, PPARG rs1801282 (Pro12Ala) and HNF4A rs2144908. Genotype-phenotype correlation analysis revealed that rs1799854 in ABCC8 was associated with 2-hour postprandial insulin secretion (P = 0.005) after adjusting for sex, age and BMI. Although no interactions between the four variants on the risk of type 2 diabetes were detected, the multiplicative interaction between PPARG Pro12Ala and HNF4A rs2144908 was found to be associated with 2-hour postprandial insulin (P = 0.004 under an additive model for rs2144908; and P = 0.001 under a dominant model for rs2144908) after adjusting for age, sex and BMI, assuming a dominant model for PPARG Pro12Ala.</p><p><b>CONCLUSIONS</b>Our study replicated the association of rs5219 in KCNJ11 with type 2 diabetes in Chinese Han population in Beijing. And we also observed that ABCC8 as well as the interaction between PPARG and HNF4A may contribute to post-challenge insulin secretion.</p>
Assuntos
Adulto , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Transportadores de Cassetes de Ligação de ATP , Genética , Índice de Massa Corporal , Diabetes Mellitus Tipo 2 , Genética , Predisposição Genética para Doença , Genética , Genótipo , Fator 4 Nuclear de Hepatócito , Genética , PPAR gama , Genética , Polimorfismo de Nucleotídeo Único , Genética , Canais de Potássio Corretores do Fluxo de Internalização , Genética , Receptores de Droga , Genética , Receptores de SulfonilureiasRESUMO
<p><b>OBJECTIVE</b>To explore novel pathogenic mutation in the mitochondrial DNA gene in diabetic pedigree.</p><p><b>METHODS</b>Twenty-eight suspected mitochondrial DNA diabetic families were recruited. The gene fragment was produced by PCR, and mutation was detected by direct sequencing.</p><p><b>RESULTS</b>In one pedigree, the proband and her mother were found carrying the most common nt3243 A --> G mutation and another 16S rRNA 3205C --> T mutation. But only 3205C --> T was found in her affected brother. All the two patients were deaf and developed diabetes in early age, characterized by impaired beta cell function and low body mass index (BMI). The proband had relatively higher lactic acid concentration than normal individuals. A novel ND1 gene 3434 A --> G(TAT --> TGT) mutation was explored in another proband with deafness and her affected family members.</p><p><b>CONCLUSION</b>16SrRNA 3205C --> T mutation was found in a mitochondrial diabetes mellitus pedigree, implying its potential pathogenic role in diabetes. Another novel ND1 3434 A --> G mutation was found in another diabetic pedigree. Because this mutation causes amino acid change (Tyr --> Cys) and is co-segregated with diabetes, it may be diabetogenic.</p>