[Identification of 2 allelic mutations of the gene of the phosphodiesterase beta subunit in a Spanish family with recessive autosomic retinitis pigmentosa].

BACKGROUND

Retinitis pigmentosa (RP) is a group of inherited eye disorders that affect photoreceptor and pigment epithelial function. Mutations in different genes involved in the phototransduction process have been described in patients with autosomal recessive RP.

PATIENTS AND METHODS

We examined the gene coding the beta subunit of the phosphodiesterase (PDEB) in a ARRP family with two affected sisters. SSCP (single stand conformational polymorphism) analysis of the coding region of the gene showed abnormal bands in two different exons. PCR products showing SSCP aberrant patterns were subsequently sequenced.

RESULTS

The two affected sisters had inherited from their father a PDEB gene with a known mutation (Gln298X) and a rare variant and from their mother a PDEB gene with a new mutation: Asp600Asn.

CONCLUSIONS

The nature of the mutations in the PDEB gene and their pattern of inheritance indicate that the lack of activity of the phosphodiesterase (PDE), a key enzyme in the visual phototransduction process, account for the RP phenotype in these patients.