Hypothalamic hamartomas are congenital malformations. The association
between hypothalamic hamartomas and other dysplasias, including polyda
ctyly, is known to be a neonatal lethal syndrome. We report on two pat
ients (mother and son) with asymptomatic large hypothalamic hamartomas
and polysyndactyly. The relationship of the patients suggests an auto
somal dominant transmission.