One in a group of disorders resulting in overgrowth,
Sotos syndrome is characterized by an unusually large
and increased height
and head circumference. It is associated with
neonatal jaundice, scoliosis, seizures, conductive
hearing loss, congenital cardiac anomalies, renal anomalies,
and behavioral problems. There is an increased risk of
cancer with this and other overgrowth syndromes.
Mutations in the NSD1 gene cause Sotos syndrome. The NSD1 gene provides instructions for making a protein that is involved in normal growth and development. The function of this protein is unknown, however. In the Japanese population, the most common genetic change leading to Sotos syndrome deletes genetic material from the region of chromosome 5 containing the NSD1 gene. In other populations, small mutations within the NSD1 gene occur more frequently. Genetic changes involving the NSD1 gene prevent one copy of the gene from producing any functional protein which leads to features of Sotos syndrome. NSD1
is the only known gene to be associated with Sotos
80-90% of individuals
with Sotos syndrome have a mutation or
deletion of NSD1.
Sequencing is the first tier test for this disorder. If no mutation is found we recommend FISH as the second tier test.
Methodology: Sequencing of entire coding region
Purpose: Confirmation of Clinical Diagnosis
ICD-10 Code Q87.3
Test Requisition: Sequencing Requisition
CPT Codes: 81406 Cost: $1500.00
Turn-around-time: 5-6 weeks
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