CONGENITAL RECESSIVE ICHTHYOSIS UNLINKED TO LOCI FOR EPIDERMAL TRANSGLUTAMINASES

Congenital recessive ichthyosis has a broad range of clinical presenta tions, which may be considered a spectrum of phenotypes with classic l amellar ichthyosis at one pole and classic congenital ichthyosiform er ythroderma at the other. The identification of mutations in the transg lutaminase-1 gene as a cause of lamellar ichthyosis implicates transgl utaminases in other congenital recessive ichthyoses. We investigated t wo multiplex families with clinical manifestations between the two pol es for linkage to the transglutaminase-1 locus on chromosome 14. Stron gly negative lod scores prompted a search for linkage to two other epi dermally expressed transglutaminases, transglutaminase-2 and transglut aminase-1, on chromosome 20. No evidence for linkage was found. These data confirm the hypothesis that the congenital recessive ichthyoses a re genetically heterogeneous and in two families exclude two other tra nsglutaminases that could be considered as candidate loci for at least some of the nonlamellar recessive ichthyoses.