Arthrogryposis multiplex congenita with polymicrogyria and infantile encephalopathy caused by a novel GRIN1 variant.

Variants of GRIN1, which encodes GluN1, are associated with developmental delay, epilepsy, and cortical malformation. Here, we report a case of arthrogryposis multiplex congenita with polymicrogyria and infantile encephalopathy caused by a heterozygous variant, c.1949A>C, p.(Asn650Thr) of GRIN1, which could result in the disruption of the third transmembrane domain (M3) of GluN1. This case expands our understanding of the known phenotypes of GRIN1-related neurodevelopmental disorders.