Expanding the phenotype of CARS1 variants to include congenital hyperinsulinism.

BACKGROUND: CARS1 loss of function compound heterozygous or homozygous variants have been reported in five individuals to cause a neurodevelopmental phenotype that includes microcephaly and brittle hair and nails. Additional multisystem involvement in these five people have included neurologic, cardiac, ophthalmologic and endocrine problems. CASE PRESENTATION: We report a sixth person with novel compound heterozygous variants in CARS1. In addition to the previously reported features such as intellectual disability, neurologic features, microcephaly and hair abnormalities, this patient had persistent hypoglycemia due to congenital hyperinsulinism. CONCLUSIONS: This report identifies two novel variants in CARS1 and expands the phenotype of this multisystem disorder to include congenital hyperinsulinism.