| pubmed-article:19938247 | pubmed:abstractText | Pitt-Hopkins syndrome is characterized by severe mental retardation, characteristic dysmorphic features, and susceptibility to childhood-onset seizures and intermittent episodes of hyperventilation. This syndrome is caused by haploinsufficiency of TCF4, which encodes a basic helix-loop-helix transcription factor. Missense, nonsense, splice-site mutations, and gene deletions have been found in individuals with Pitt-Hopkins syndrome. Previous reports have suggested that the Pitt-Hopkins syndrome phenotype is independent of mutation or deletion type. | lld:pubmed |
