OMIM ID:
Retinal Dystrophy, Cataracts, and Short Stature
Alternate Names
Defective Genes
Clinical Characteristics
Ocular Features
Patients develop progressive night vision problems in the first decade of life. However, central acuity remains in the 20/20 to 20/30 range at least through the second decade. Cataracts are noted during this time period as well. Visual field constriction is present.
Pigmentary retinopathy is present, especially in the posterior poles. Macular mottling is evident at an early age with attenuation and narrowing of the retinal arterioles. The pigmentary changes are salt-and-pepper in appearance but there are also areas of RPE atrophy with relative sparing of the fovea. Pigment clumping in the shape of bone spicules has been observed in the periphery. Full field ERGs show generalized rod-cone dysfunction with scotopic function more affected. OCT examination reveals a disruption of the outer retinal layers from the parafoveal region into the periphery.
Systemic Features
Early childhood psychomotor delays are evident in early childhood by the lack of fine motor and coordination skills along with learning difficulties. Patients have facial dysmorphism with hypoplasia of the ala nasae, upslanting palpebral fissures, and malar hypoplasia. The teeth are widely spaced and there is malocclusion. Short stature is characteristic (fifth percentile).
Genetics
Inheritance
This disorder results from homozygosity of mutations in the RDH11 gene (14q24) encoding retinol dehydrogenase 11.
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.