Background:
Disseminated superficial actinic porokeratosis (dsap) is a chronic cutaneous disorder characterized by multiple superficial keratotic lesions surrounded by a slightly raised keratotic border. it develops in teenagers in sun-exposed areas of skin and usually follows an autosomal dominant inheritance pattern. the first locus for dsap was localized to chromosome 12q23.2-24.1, but no gene responsible for porokeratosis has been identified to date.
Objectives:
To determine whether dsap is a genetically heterogeneous disorder and to identify the disease gene locus in a three-generation chinese family with dsap.
Methods:
Genetic linkage analysis was carried out in this family using 15 microsatellite markers between d12s1671 and d12s369 on chromosome 12q, followed by a genome-wide scan with 382 microsatellite markers from the autosomes.
Results:
Genetic linkage analysis with chromosome 12q markers suggested that the locus in this family is not linked to chromosome 12q. a genome-wide scan and fine mapping finally localized the locus for dsap in this family to a 6.4-cm region between markers d15s1023 and d15s1030 at chromosome 15q25.1-26.1. this dsap locus was named dsap2.
Conclusions:
The previous results and this study have shown that dsap is a genetically heterogeneous disorder; a novel locus for dsap, termed dsap2, was mapped to a 6.4-cm region between markers d15s1023 and d15s1030.