Clinical and morphological correlations for transglutaminase 1 gene mutations in autosomal recessive congenital ichthyosis

Autosomal recessive congenital ichthyosis (ARCI) is a group of inherited di sorders of cornification in which progress has recently been made in the id entification of pathogenic mechanisms causing the disease, Transglutaminase 1 (TGM1) has been found as a defective gene in a large fraction of patient s with lamellar ichthyosis (LI), a severe inherited scaling disorder of the skin, We have previously performed molecular genetic studies of 38 Finnish ARCI families and found six different mutations in 13 families of 38 (34%) , In this study we compared the molecular genetic alterations with clinical and electron microscopic findings of these patients, Families were classif ied by electron microscopy in ichthyosis congenita (IC) typesI, II, III, IV and a non-defined group, TGM1 gene mutation was found in all of the IC typ e II and 1/3 of the IC type 1 families, Although electron microscopy is not always used to classify ARCI patients, it can distinguish groups which are parallel with molecular genetic findings, This finding might be useful in the classification of ARCI patients for further linkage studies, Clinically typical phenotype of the TGM1 mutation carrier includes large, thick, brow nish scales, but ichthyosis of some of these patients tends to be milder.