Long-term follow-up of retinitis pigmentosa patients with multifocal electroretinography.

Purpose: To study the rate of multifocal electroretinographic (mfERG) response amplitude changes and their relation to other parameters of disease development in retinitis pigmentosa (RP).

Methods: Twenty-three patients (9 men and 14 women) with clinically defined RP were included in the study. Disease progression was monitored during a period of up to 10 years by psychophysical techniques and Ganzfeld electroretinography.

Usher syndrome type 1 due to missense mutations on both CDH23 alleles: investigation of mRNA splicing.

Usher syndrome (USH) is an autosomal recessive condition characterized by sensorineural hearing loss, vestibular dysfunction, and visual impairment due to retinitis pigmentosa. Truncating mutations in the cadherin-23 gene (CDH23) result in Usher syndrome type 1D (USH1D), whereas missense mutations affecting strongly conserved motifs of the CDH23 protein cause non-syndromic deafness (DFNB12). Four missense mutations constitute an exception from this genotype-phenotype correlation: they have been described in USH1 patients in homozygous state.