Lamellar ichthyosis with a novel homozygous C-terminal mutation in the transglutaminase-1 gene

The majority of cases of Lamellar ichthyosis (LI) are caused by mutations in the transglutaminase-1 (TGM1) gene. The mutations in the beta-barrel domains of the TGM1 gene are found very infrequently and several authors have suggested that these domains are not essential for the function of the enzyme. Other authors have postulated that mutations in these loci are pathogenic but they imply a less severe clinical picture of LI.

We report a patient with a severe phenotype of LI who had a homozygous mutation affecting the beta-barrel 2 domain of the TGM1.

This finding indicates that the integrity of beta-barrel domains is important for the correct function of the enzyme and that we are still far away from a consistent genotype-phenotype correlation.