Abstract
Purpose: :
To describe the co-incidence of cone dystrophy and alopecia in two siblings and its associated genetics.
Methods: :
A 14 year-old patient and her 9 year-old brother were followed from their initial presentation of decreased vision OU secondary to cone dystrophy through a 5 year period. Confirmatory examination was performed and included ERG, color plates, and fundus examination.
Results: :
Both siblings developed classic signs of cone dystrophy around the age of 9, as confirmed by ERG, Fundus FA and color plates. Cone dystrophy along with congenital hypotrichosis in both siblings was determined to be an autosomal recessive disorder. As determined by a previously published case report the gene for this disorder has been localized to 16q22.1, the region containing CDH3 which encodes P-cadherin, that is expressed in both retinal pigment epithelium and hair follicle. The cadherins are involved in the regulation of both hair and retinal development.
Conclusions: :
The association of cone dystrophy and congenital hypotrichosis, although rare has been determined to be an autosomal recessive inheritance pattern of the defective 16q22.1 gene. This gene defect leads to abnormal P-cadherins and altered cell-cell adhesion.
Keywords: retinal pigment epithelium • gene/expression • innervation: neural regulation