[Frequency and effect on plasma lipoprotein metabolism of a mutation in the cholesteryl ester transfer protein gene in the Chinese].

The aspartate to glycine substitution at codon 442 (D442G) in the cholesteryl ester transfer protein (CETP) gene is a common mutation in Japan and is thought to be a factor that elevates the serum high-density lipoprotein (HDL)-cholesterol level in the general Japanese population. In the present study, we investigated the frequency of the D442G mutation in the Chinese subjects living in Beijing. We also studied the effects of the mutation on plasma lipoprotein metabolism in the same population and compared it with that in the Japanese Diagnosis of D442G mutation was established by polymerase chain reaction followed by restriction digestion. Among 379 subjects studied, 16 were found heterozygous thereto (allelic frequency = 2.1%). Unexpectedly, the D442G mutation was not associated with elevated HDL-cholesterol levels in the Chinese. Instead, in comparison to the unaffected, significantly decreased low-density lipoprotein (LDL)-cholesterol and total cholesterol levels were observed in the heterozygotes. These results were discrepant from those obtained in Japan: Japanese D442G heterozygotes had elevated HDL-cholesterol levels with unchanged LDL-cholesterol and total cholesterol levels. The divergence in the effect of D442G mutation on plasma lipoprotein metabolism appears to be related to the significantly low CETP activities in the Chinese affected and unaffected. Although the difference between Japan and China in nutritional conditions is supposed to contribute to the divergence, the precise mechanism remains to be determined.