Assignment of a novel locus for autosomal recessive congenital ichthyosis chromosome 19p13.1-p13.2

Autosomal recessive congenital ichthyosis (ARCI) is a rare, clinically and genetically heterogeneous genodermatosis. One gene (transglutaminase 1, on 14q11) and one additional locus (on 2q33-35, with an unidentified gene) hav e been shown to be associated with a lamellar, nonerythrodermic type of ARC I. We performed a genomewide scan, with 370 highly polymorphic microsatelli te markers, on five affected individuals from one large Finnish family with nonerythrodermic, nonlamellar ARCI. The only: evidence for Linkage emerged from markers in a 6.0-cM region on chromosome 19p13.1-2. The maximum two-p oint LOD score of 7.33 was obtained with the locus D19S252, and multipoint likelihood calculations gave a maximum location score of 5.2. The affected individuals share two common core halotypes, which makes compound heterozyg osity possible. The novel disease Locus is the third focus linked to ARCI, supporting previous evidence for genetic heterogeneity of ARCI. This is als o the first locus for a nonlamellar, nonerythrodermic phenotype of ARCI.