This is a severe heritable neurological condition with facial anomalies and slow development secondary to brain deformities.
Infants are born with small heads (microcephaly) and their muscles seem stiff which may lessen later. Excessive hair (hirsutism) is generally present with a low hairline in the front, bushy eyebrows, and long eyelashes. The eyelids appear puffy. The ears protrude, are lower than normal, and often rotated towards the back of the head. The lower lip seems to protrude while the nose openings point forward. Uncoordinated hand movements and a general unsteadiness (ataxia) are usually present. Brain imaging reveals structural malformations. Speech is poor or never develops and cognitive functioning is poor. Physical growth is slow.
This is an autosomal recessive condition caused by mutations in a pair of specific genes. Parents who usually carry only one mutation are clinically normal but the offspring of two such parents each inherit a 25% risk of having this condition.
The physical anomalies should suggest the diagnosis at birth while many of the neurological deficits become evident as children grow. Pediatricians and neurologists are likely to collaborate in the diagnosis and follow-up. Nothing is known regarding longevity but patients have severe physical limitations and may require a wheelchair for locomotion.