Question: What is (are) Sotos syndrome ?
Answer: Sotos syndrome is a condition characterized mainly by distinctive facial features; overgrowth in childhood; and learning disabilities or delayed development. Facial features may include a long, narrow face; a high forehead; flushed (reddened) cheeks; a small, pointed chin; and down-slanting palpebral fissures. Affected infants and children tend to grow quickly; they are significantly taller than their siblings and peers and have a large head. Other signs and symptoms may include intellectual disability; behavioral problems; problems with speech and language; and/or weak muscle tone (hypotonia). Sotos syndrome is usually caused by a mutation in the NSD1 gene and is inherited in an autosomal dominant manner. About 95% of cases are due to a new mutation in the affected person and occur sporadically (are not inherited).
Source: GARD

Question: Is Sotos syndrome inherited ?
Answer: How is Sotos syndrome inherited? Sotos syndrome is inherited in an autosomal dominant manner. This means that having a mutation in only one of the 2 copies of the responsible gene (the NSD1 gene) is enough to cause signs and symptoms of the condition. 95% of people with Sotos syndrome do not inherit the condition from a parent. In these cases, the condition is the result of a new (de novo) mutation that occurred for the first time in the affected person. Only about 5% of people with Sotos syndrome have an affected parent and inherit the condition from that parent. If a parent of an affected person with an identified NSD1 mutation does not have any features of Sotos syndrome, that parent is very unlikely to have a mutation in the gene. This can be confirmed with genetic testing if the mutation has been identified in the child. If a person with Sotos syndrome has children, each child has a 50% (1 in 2) chance to inherit the mutation. However, the specific features and severity can vary from one generation to the next, so it is not possible to predict how a child will be affected.
Source: GARD