A rare genetic syndrome that can affect both cognitive and physical development, with variations in severity. Males typically present with severe symptoms, including profound mental disability, developmental delay, and skeletal abnormalities. The female presentation is more varied, with some cases exhibiting almost no symptoms, and other cases matching the male presentation in severity. The most recognizable traits include soft hands with short, tapered fingers, microcephaly, short stature, kyphoscoliosis, and hypotonia. Many patients have characteristic facial deformities such as broad nose, prominent brow, hypertelorism, maxillary hypoplasia, teeth abnormalities, thick lips, high-arched palate, and large ears.

Beginning in childhood, some patients may also suffer from stimulus-induced drop attacks, brief collapses induced by excitement or loud noises. These can be treated with antiepileptics.

The condition is X-linked and caused by mutations in the RPS6KA3 gene. Up to 70%-80% of cases occur spontaneously with no other affected family members. Treatment is supportive, and patients should be monitored for potentially life-threatening kyphoscoliosis.

This is a rare X-linked syndrome.