GRM6 and congenital stationary night blindness: Huynh and co-workers (2014) reported a case of a female patient with STGD1 and complete congenital stationary night blindness (CSNB1B), carrying biallelic ABCA4 variants (p.(Leu1201Arg) and p.(Arg2077Gly)) along with biallelic GRM6 gene variants (c.50_64del and c.1835_1837del) [16].