Pallister-Hall syndrome

Pallister-Hall syndrome is a rare inherited disorder that affects several body systems at once. Its two defining features are a non-cancerous mass on the hypothalamus, called a hypothalamic hamartoma, and extra fingers or toes, with the skin between some digits sometimes fused. The hamartoma may cause no trouble, but in some people it leads to seizures, classically brief laughing or gelastic seizures, or to hormone abnormalities. Other features can include a split in the airway, a blocked anal opening and kidney abnormalities, and severity ranges from mild to severe. The condition is caused by a shortened, altered GLI3 gene and passes in an autosomal dominant pattern, though some cases arise from new mutations. It was first described by the geneticists Philip Pallister and Judith Hall, and about one hundred cases have been reported in the literature.