[Prenatal diagnosis of congenital insulin-resistant diabetes (Donohue's syndrome)].

A consanguineous Turkish couple was expecting their third child. Two years earlier their second child had died from a severe form of insulin-resistant diabetes causing Donohue's syndrome. A novel mutation (V335) in the insulin receptor gene was found to be disrupting the structure and function of the receptor. The parents, as well as their first child, were asymptomatic, heterozygous carriers. The family received genetic counselling, and chorion villus sampling was performed early in pregnancy. Genotyping showed that the child in utero was heterozygous for the mutation. Subsequently the mother gave birth to a healthy boy.