The mutation of insulin receptor substrate-1 gene in Chinese patients with non-insulin-dependent diabetes mellitus.
OBJECTIVE
To identify the relationship between mutation in the insulin receptor substrate-1 (IRS-1) gene and the incidence of non-insulin-dependent diabetes mellitus (NIDDM) in the Chinese population.


METHODS
Samples were obtained from 68 Chinese patients with NIDDM and 68 control subjects. The +1700-(+)4437 bp fragment of the IRS-1 gene was screened by polymerase chain reaction (PCR)-single strand conformation polymorphism (SSCP) analysis. All SSCP variations were submitted to DNA sequence analysis.


RESULTS
Two amino acid variations [GGG-->AGG (G971 R) and CCT-->TCT (P1079 S)] and 3 silent mutations [GAT-->GAC(D422D), CCA-->CCC(P737 P) and GCA-->GCG (A804 A)] were identified, among which the CCA-->CCC(P737 P) and CCT-->TCT(P1079S) have not been previously reported. All five variations were found in Chinese patients with NIDDM, while GCA-->GCG(A804A) was the only one found in control subjects. The overall incidence of the five variations in Chinese patients with NIDDM were much higher than that in control subjects (38.2% vs 7.4%, chi 2 = 18.42, P < 0.01). The most common polymorphism in the Chinese population was GCA-->GCG (A804A), and its frequency was significantly higher in Chinese patients with NIDDM than in controls (26.5% vs 7.4%, chi 2 = 8.84, P < 0.01). The homozygotes of the variation in patients with NIDDM and control subjects were 8.8% and 1.5%, respectively (chi 2 = 2.41, P > 0.05).


CONCLUSIONS
These results indicate that there may be a relation between these nucleotide variations of IRS-1 gene and Chinese patients with NIDDM.
Zeng
W
W
Department of Biochemistry, Hunan Medical University, Hunan 410078, China.
Peng
J
J
Wan
X
X
Chen
S
S
Song
H
H
D000328:Adult; D000368:Aged; D003924:Diabetes Mellitus, Type 2 / Q000235:genetics*; D006801:Humans; D055504:Insulin Receptor Substrate Proteins; D008875:Middle Aged; D009154:Mutation; D010750:Phosphoproteins / Q000235:genetics*
C526292:IRS1 protein, human; D055504:Insulin Receptor Substrate Proteins; D010750:Phosphoproteins