Gonadal mosaicism of Frasier syndrome in 3 Chinese siblings with donor splice site mutation of Wilms' tumour gene.

Frasier syndrome is a rare human developmental disorder classically affecting 46,XY females and leading to male pseudohermaphroditism and chronic renal failure. We describe a family with both 46,XX and 46,XY females affected by the syndrome due to WT1 splice site mutations. The diagnosis of Frasier syndrome in 1 of the children led to the discovery of the syndrome in 2 other siblings, of whom 1 is asymptomatic. Since the mutation was not found in either parents, gonadal mosaicism was suggested. The implication of family screening for WT1 gene mutation in asymptomatic members is also discussed.