Many times genetic testing is the only solution to avoid a never-ending diagnostic odyssey.
A 5-month-old male presented with hypotonia, neonatal hypoglycemia, a sacral vestigial tail, and reflux.
Previous genetic testing
Previous testing included over a dozen different investigations without a diagnosis (genetic, biochemical, and imaging testing).
A Whole Exome Family Plus Test, including sequencing and CNV analysis for the proband and unaffected parents, was requested.
The patient was identified to have a heterozygous nonsense variant, c.5543T>G, p.(Leu1848*) in NSD1. This variant has been identified in a cohort of individuals with a clinical diagnosis of Sotos syndrome.
As the NSD1 variant was not identified in either parent, the risk for the patient’s parents to have another affected child is expected to be low.
Blueprint Genetics’ Take Home
After a diagnostic odyssey involving over a dozen different investigations, none of which were informative, the WES Family Plus analysis at Blueprint Genetics was able to make a diagnosis of Sotos syndrome and provide an answer for the family.