Linkage of a locus determining familial progressive hyperpigmentation (FPH) to chromosome 19p13.1-pter in a Chinese family.

Familial progressive hyperpigmentation (FPH) is a rare autosomal dominantly inherited disorder characterized by patches of hyperpigmentation in the skin which are present at birth or in early infancy and increase in size and number with age. Although previous studies showed that FPH is a monogenic trait, the genetic basis for this disease is unknown. Using a genome screening with 182 STR markers from autosomes in a three-generation Chinese family with 17 members, including 6 affected individuals, we identified a locus linked to chromosome 19p13.1-pter responsible for FPH, spanning 45.48 cM between D19S593 and 19pter. Interestingly, this region harbors the LKB1 gene, in which germline mutations were shown to be associated with Peutz-Jeghers Syndrome (PJS). PJS and FPH share the disorder of hyperpigmentation, the fine mapping of the FPH gene is expected to lead to a better understanding of the etiology for both FPH and PJS. The linkage of FPH locus to human chromosome 19p13.1-pter provides a genetic basis for further fine mapping.