Nine mutations, six of which are novel, in the pre-mRNA splicing-factor genes PRPF3, PRPF8, and PRPF31, causing adRP have been identified in the Spanish population. Their contribution to adRP is approximately 5% after correction in relation to mutations found in other genes causing adRP. The patients carrying a mutation in the pre-mRNA splicing-factor PRPF8 gene showed a type 1 diffuse RP. The existence of asymptomatic carriers of the nonsense mutation in the PRPF31 gene suggests incomplete penetrance for these mutations in the families.

Retinitis pigmentosa is the most prevalent inherited disorder of the retina. It can be autosomal dominant (adRP), autosomal recessive (arRP) or X-linked (XLRP). A form of adRP mapping to chromosome 7q was reported in a large Spanish pedigree. We have typed DNA from the members of another Spanish family for polymorphic markers from the known candidate genes. Positive lod scores were obtained only for the markers located on 7q31-35, giving a maximum lod score of 2.98 (3.01 by multipoint analysis) at theta = 0.00 for D7S480. A brief clinical evaluation is given.

Retinitis pigmentosa (RP) is a clinically and genetically heterogeneous form of retinal degeneration. Several genes and loci have been shown to be involved in the disease, although each of them could only account for a few cases. Mutations in the gene encoding ROM1, a rod-specific protein, have been putatively associated with several forms of RP. Here we describe a double mutant allele of this gene, P60T and T108M, present in two affected sibs and also in two healthy members of a Spanish RP family. The same double mutant allele was previously considered to be responsible for autosomal dominant RP in one family. We now report data that questions the potential pathogenicity of these two ROM1 mutations.3

A study was made of two families with autosomal dominant retinitis pigmentosa (ADRP) from Valencia (Spain). One family (ADRP15) was found to have mutation in codon 114 of the rhodopsin gene that led to a substitution of a glycine for an aspartic acid. The second family (ADRP7) substituted an aspartic acid for valine in codon 173 of the peripherin-RDS gene. Rhodopsin is involved in 25% of ADRP cases and many mutations of this gene have been described as causing different forms of the disease, with variable severity and age at onset. ADRP has been classified as RP with a milder symptom evolution, a typical RP fundus pattern, and macular involvement occurring after the second decade of life. Peripherin-RDS gene mutations lead to RP or other retinopathies. Furthermore, two mutations in codon 172 have been described as causing macular dystrophy. In ADRP7, a mutation in neighboring codon 173 produced RP with an atypical fundus pattern and macular involvement within the first decade of life. These observations confirm the established clinical and genetic heterogeneity involved in this form of RP.

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