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.