It has been shown recently that autosomal dominant retinitis pigmentosa may be caused by point mutations of the rhodopsin gene in a portion of families. In this communication, a large six-generation family with autosomal dominant RP is described. Molecular analysis by PCR amplification followed by restriction digestion or heteroduplex analysis suggested a point mutation in codon 347, in which two different mutations (Pro-347-Ser and Pro-347-Leu) have already been reported. Direct sequencing of the patients' DNA revealed a previously undescribed CCG----CGG transversion in codon 347 predicting a Pro----Arg substitution. Ophthalmological data of the patients are summarized and compared to those of patients with other mutations in the rhodopsin gene.