The islet amyloid polypeptide (amylin) gene S20G mutation in Chinese subjects: Evidence for associations with type 2 diabetes and cholesterol levels

BACKGROUND and OBJECTIVES There has been evidence that the S20G mutation in the islet amyloid polypeptide (amylin) gene may be associated with type 2 diabetes. In the present study, we investigated the distribution of the mutation in Hong Kong Chinese. and examined whether there was evidence for associations between the mutation and type 2 diabetes and/or metabolic profiles. SUBJECTS and METHODS This study involved 227 early anti 235 late-onset (defined as onset age less than or equal to 40 and > 40 years, respectively) type 2 diabetic patients, as well as 126 nondiabetic subjects. The mutation was detected using a PCR-RFLP method. RESULTS We identified six (2.6%) and one (0.4%) patients heterozygous for the mutation from the early and late-onset groups, respectively (P = 0.05). None of the nondiabetic subjects had the mutation. Insulin deficiency and poor glycaemic control were not common findings amongst carriers of the mutation, In the early onset group, the patients with the mutation had lower plasma levels of total (4.3 +/- 0.9 mmol/l vs. 5.3 +/- 1.1 mmol/l, P = 0.02) and low density lipoprotein (LDL)-cholesterol (2.3 +/- 0.7 mmol/l vs. 3.2 +/- 0.9 mmol/l, P = 0.01) than those without the mutation. CONCLUSIONS Our data suggest that the islet amyloid polypeptide gene mutation might be associated with early occurrence of type 2 diabetes and lower plasma levels of total and low density lipoprotein-cholesterol in the Chinese population.