Moreover, a rare heterozygous missense variant, c.2539G > A (p.E847K), in the main ubiquitous somatic isoform (NM_000188) of HK1 has been reported to cause retinitis pigmentosa 79 with an autosomal dominant pattern of inheritance (OMIM #617460).22 Recently, four de novo variants located in the conserved catalytic domain shared among all the isoforms are reported to be involved in the pathogenesis of a neurodevelopmental disorder with visual defects and brain anomalies (OMIM# 618547, Figure 1C).6,19,23. Here, HK1 is linked to retinitis pigmentosa.