• retinitis pigmentosa 4

This report describes retinitis pigmentosa 4 (RP4), which is a subtype of retinitis pigmentosa. The human gene implicated in this disease is the rhodopsin gene RHO. This form of retinitis pigmentosa is typically inherited as an autosomal dominant. In humans, the RHO gene is also associated with several other retinal diseases (MIM:180380). Both humans and flies have multiple rhodopsin genes. Many of the orthologous human genes are associated with retinal disease; see the report 'retinal disease, rhodopsin-related' (FBhh0000219).

Dmel\ninaE and Dmel\Rh6 are the best orthologous hits to human RHO, however, each of these two fly genes also has moderate-scoring hits to other rhodopsin genes in humans. Dmel\ninaE has been extensively characterized; classical amorphic and hypomorphic alleles, RNAi-targeting constructs, and alleles caused by insertional mutagenesis have been generated for this gene. For Dmel\Rh6, a more limited number of classical mutations and RNAi-targeting constructs are available.

The human RHO gene has not been introduced into flies.

Variant(s) implicated in human disease tested (as analogous mutation in fly gene): P37H in the fly ninaE gene (corresponds to P23H in the human RHO gene).

In animals carrying null mutations of ninaE, the adult compound eye does not develop normally. There are defects in the rhabdomeres of photoreceptor cells R1-R6; progressive retinal degeneration is observed. Expression of a transgenic ninaE allele analogous to a known RP4 mutation in the human RHO gene results in progressive retinal degeneration in adults. Many genetic and physical interactions of Dmel\ninaE have been described; see below and in the gene report for ninaE.

[updated Jun. 2017 by FlyBase; FBrf0222196]