Mapping of a second locus for lamellar ichthyosis to chromosome 2q33-35 [published erratum appears in Hum Mol Genet 1996 Jun;5(6):862-3]

Lamellar ichthyosis (LI) is an inherited autosomal recessive disorder ofcornification. It was recently demonstrated to result from deleteriousmutations in the transglutaminase 1 (TGM1) gene. However, the disease wasshown to be genetically heterogeneous, since some families were found to beunlinked to TGM1. Homozygosity mapping on three consanguinous familiesoriginating from Morocco shows (i) absence of linkage with TGM1 and otherregions of the genome containing genes involved in cornification, and (ii)location of a second disease- causing gene on chromosome 2q33-35. A maximumtwo-point lodscore of 7.60 was obtained with D2S157 for theta = 0. Theanalysis of recombination events places the gene within a 7-8 cM interval.Additional consanguinous pedigrees were also demonstrated to be unlinkedboth to TGM1 and to 2q33-35, suggesting the existence of at least a thirddisease-causing gene.