This report expands the spectrum of NRL recessive mutations, as well as the genetic spectrum of ESCS, and indicates a new syndrome of OPMD with an ESCS-like phenotype.
The neural retina leucine zipper transcription factor-knockout (Nrl(-/-)) mouse model demonstrates many phenotypic features of human ESCS, including unstable S-cone-positive photoreceptors.
The neural retina leucine zipper transcription factor-knockout (Nrl(-/-)) mouse model demonstrates many phenotypic features of human ESCS, including unstable S-cone-positive photoreceptors.
Loss-of-function NRL alleles have not been described previously in humans, but since the same mutation was present in unaffected family members, it raises the possibility that the abnormal ESCS phenotype in Patient A may result from a digenic mechanism, with a heterozygous NRL mutation and a mutation in another unknown gene.