Sotos syndrome

Sotos syndrome it is an autosomal dominant syndrome considered as a form of cerebral gigantism, mainly characterised by prenatal and postnatal overgrowth.

Epidemiology

There is no ethnic group predominance and has been detected throughout the world. The prevalence is not known but is estimated to be between 1:10,000 and 1:50,000 ⁵.

Clinical presentation

• increased birth weight  (between the 75^th and 97^th percentile) and length (above the 97^th percentile) ⁵
• large head circumference at birth (usually above the 97th percentile) ⁵
• macrocephaly
• excessive growth in the first years of life
• craniofacial dysmorphisms such as dolichocephaly, prominent forehead, hypertelorism, epicanthic folds, flat nasal bridge, down-slanting palpebral fissures, high arched palate, premature eruption of teeth and pointed chin ⁶
• intellectual disability and developmental delay 

Pathology

It is an autosomal dominant syndrome with the majority of cases being described as sporadic ⁵.

Radiographic features

Increased bone age documentation is a pre-requisite to diagnosis as it is thought that all cases have an advanced bone age at some time ⁵. 

MRI/CT

Identifiable features include:

• cerebral ventricular abnormalities 
  • prominent trigone
  • colpocephaly
  • ventriculomegaly
• anomalies of midline structures
  • corpus callosal dysgenesis
  • persistent cavum velum interpositum

History and etymology

It was first described by Juan F. Sotos et al. in 1964 ⁴. 

Differential diagnosis

For a large head: see causes of macrocephaly.