TY - JOUR T1 - A novel homozygous truncating <em>GNAT1</em> mutation implicated in retinal degeneration JF - British Journal of Ophthalmology JO - Br J Ophthalmol SP - 495 LP - 500 DO - 10.1136/bjophthalmol-2015-306939 VL - 100 IS - 4 AU - Matthew Carrigan AU - Emma Duignan AU - Pete Humphries AU - Arpad Palfi AU - Paul F Kenna AU - G Jane Farrar Y1 - 2016/04/01 UR - http://bjo.bmj.com/content/100/4/495.abstract N2 - Background The GNAT1 gene encodes the α subunit of the rod transducin protein, a key element in the rod phototransduction cascade. Variants in GNAT1 have been implicated in stationary night-blindness in the past, but unlike other proteins in the same pathway, it has not previously been implicated in retinitis pigmentosa.Methods A panel of 182 retinopathy-associated genes was sequenced to locate disease-causing mutations in patients with inherited retinopathies.Results Sequencing revealed a novel homozygous truncating mutation in the GNAT1 gene in a patient with significant pigmentary disturbance and constriction of visual fields, a presentation consistent with retinitis pigmentosa. This is the first report of a patient homozygous for a complete loss-of-function GNAT1 mutation. The clinical data from this patient provide definitive evidence of retinitis pigmentosa with late onset in addition to the lifelong night-blindness that would be expected from a lack of transducin function.Conclusion These data suggest that some truncating GNAT1 variants can indeed cause a recessive, mild, late-onset retinal degeneration in human beings rather than just stationary night-blindness as reported previously, with notable similarities to the phenotype of the Gnat1 knockout mouse. ER -