Clinical case reports November 01, 2008 November 01, 2008

HNF1? mutations are present in half of clinically defined MODY patients in South-Brazilian individuals

DOI: 10.1590/S0004-27302008000800020

Maturity-onset diabetes of the young (MODY) is a monogenic form of diabetes mellitus characterized by autosomal dominant inheritance, early age of onset, and pancreatic beta cell dysfunction. Heterozygous mutations in at least seven genes can cause MODY. In the present study we investigated the relative prevalence of GCK (glucokinase) and HNF1? (hepatocyte nuclear factor 1?) mutations, the more frequent causes of MODY, in 13 South-Brazilian families with multiple cases of diabetes consistent with MODY. Heterozygous variants in GCK and HNF1? genes were observed respectively in one (7.7%), and six (46.2%) families. The six HNF1? variants are likely to cause diabetes in the families where they were observed. However, we could not ascertain whether the GCK Gly117Ser variant found in one family is a causal mutation. In conclusion, we have confirmed in a South-Brazilian population that HNF1? mutations are a common cause of monogenic diabetes in adults selected with strict clinical diagnostic criteria.