Abstract
The Pitt-Hopkins syndrome is a very rare and severe genetic disease characterized
by mental retardation, psychomotor and developmental delays with facial dysmorphism.
It was first described in 1978 in patients with mental retardation and crisis of intermittent
hyperventilation. The genetic cause is haploinsufficiency of the TCF4 (transcription factor 4) gene that affects the neurodevelopment in both sexes; the
majority of patients have spontaneous molecular defects by point mutations or deletions
in chromosome 18 at the region 18q21. The syndrome is characterized by neurological
abnormalities that affect the motor coordination and balance, in patients with mental
and developmental delays. The phenotype includes a peculiar face by specific craniofacial
anomalies: prominent square forehead, deep-set eyes with ocular hypertelorism; prominent
large nose beaked and broad flat nasal bridge; mouth wide and large, thick fleshy
lips, tented bow-shaped upper lip and everted lower lip; cup-shaped ears with dysplastic
broad overfolded helix. We review the literature and the photographs of 44 published
patients from 2007 to 2012, to resume the principal features of craniofacial anomalies,
attempting to delineate the syndrome phenotype and score the specific dysmorphism
than help to achieve the early clinical diagnosis.
Keywords
Pitts-Hopkins syndrome - facial dysmorphism -
TCF4 phenotype
