USHER SYNDROME IN 4 SIBLINGS FROM A CONSANGUINEOUS FAMILY OF PAKISTANI ORIGIN

Usher syndrome is a heterogeneous group of disorders of autosomal rece ssive inheritance characterized by retinitis pigmentosa and congenital sensorineural hearing loss. Two types are accepted clinically: type I is associated with profound congenital deafness with progressive pigm entary retinopathy and total loss of vestibular function. Type II is a milder form, with moderate-to-profound hearing loss and a milder form of retinitis pigmentosa. Vestibular function is preserved. A total of five loci have been identified as accounting for the two distinct phe notypic presentations. We describe a consanguineous family of Pakistan i origin whose four children all are affected with Usher syndrome type I. DNA analysis showed non-linkage to any of the loci already identif ied as tightly linked to the Usher syndrome type I.