Photoparoxysmal Response 3

For a phenotypic description and a discussion of genetic heterogeneity of the photoparoxysmal response, see PPR1 (132100).

Mapping

By linkage analysis of 16 families in which at least 2 sibs had PPR with or without epilepsy, Pinto et al. (2005) identified a putative disease locus on chromosome 7q32 (maximum lod score of 3.47 at marker D7S1804). All of the probands had epilepsy, and 77% of the family members with PPR had epilepsy. Ten of the probands had myoclonic seizures, suggesting that the locus represents a gene predisposing to both PPR and generalized myoclonic seizures. Evidence also suggested linkage to chromosome 16p13 (maximum lod score of 2.44 at D16S3395).