OMIM ID:
Retinitis Pigmentosa 81
Alternate Names
Defective Genes
Clinical Characteristics
Ocular Features
Patients often complain of night vision problems before the age of 5 years. Fundus changes of optic nerve pallor, retinal vessel attenuation, and bone spicule pigmentary clumping in the midperiphery are evident by the third decade of life. Progressive RPE and choroidal atrophy in the macula have been described and may be progressive. ERG responses are absent from at least 28 years of age.
Systemic Features
No systemic abnormalities have been reported.
Genetics
Inheritance
One consanguineous Pakistani family containing 9 affected members with retinal degeneration has been reported. Homozygosity of a missense mutation in the IFT43 gene (14q24.3) was found in 4 affected sibs.
Pedigree
Autosomal recessive
In order for autosomal recessive disorders to be expressed, offspring generally must inherit two mutations, one from each carrier parent. Carriers with only one mutation, such as the parents, do not have clinical disease. Note that carrier parents can expect that 1 in 4 children (25%) will inherit both mutations and have the disorder, 2 in 4 children (50%) will be carriers like their parents, while 1 in 4 children (25%) inherit neither mutation.
In order for autosomal recessive disorders to be expressed, offspring generally must inherit two mutations, one from each carrier parent. Carriers with only one mutation, such as the parents, do not have clinical disease. Note that carrier parents can expect that 1 in 4 children (25%) will inherit both mutations and have the disorder, 2 in 4 children (50%) will be carriers like their parents, while 1 in 4 children (25%) inherit neither mutation.