Sotos syndrome is a rare autosomal dominant genetic condition caused by haploinsufficiency of NSD1 gene.

Here we report on two boys with clinical features of Sotos syndrome and for who language and learning disabilities were associated with autism spectrum disorder.

The first case is a 13-year-old male born from a consanguineous couple. At birth, weight was of 3850 g, length was of 52 cm and cranial circumference was of 35 cm. At 6-month-old, the child exhibited a middle development delay and seizures with electrical disturbances of epilepsy. Monitoring of growth showed acceleration in length and cranial circumference with advanced bone age by X-ray. The boy had dysmorphic facial features including a long narrow face, a high forehead, flushed cheeks, pointed chin, down-slanting palpebral fissures and hypertelorism. Cerebral TDM showed a sus-tentorial hydrocephalus. The child manifests intellectual disability and behavioral problems with a communication phobia. The second case is a 6-year-old only child of a consanguineous couple who suffers from a male infertility with oligospermia. The boy harbours prenatal and postnatal overgrowth, persistently enlarged head circumference, dysmorphic face (with prominent forehead, pointed chin, down-slanting palpebral fissures and hypertelorism) and some other skeletal signs: cubitus valgus, pectus excavatum and large hands and feet. Motor and speech development were severely delayed and at 6 years-old, the child did not speak and did not walk. He exhibits attention deficit, hyperactivity, repetitive and stereotyped patterns of behavior.

Genetic confirmation of Sotos syndrome, symptomatic treatment, monitoring of growth and periodic surveillance were undertaken.