A novel variant of C12orf4 in a consanguineous Armenian family confirms the etiology of autosomal recessive intellectual disability type 66 with delineation of the phenotype.

This rather nonsyndromic and nonspecific clinical picture implies that additional patients with C12orf4 defects will likely continue to be identified using the "genotype-first" approach, rather than based on clinical assessment. The phenotype needs further delineation in future reports.