GRIN2A: one gene, many phenotypes

GRIN2A, a gene encoding a subunit of the N-methyl-d-aspartate (NMDA) receptor, is linked to epilepsy, language impairment, and schizophrenia, but how these associations relate to one another within individuals remains unclear. Recontacting GRIN2A carriers shows that loss-of-function variants are associated with psychiatric risk not captured in earlier ascertainment of the same cohort, highlighting how study design shapes observed gene–disease relationships.