RÉSUMÉ
This work presents the molecular genetics investigation of a male neonate referred to our genetics laboratory with the diagnosis of classical lamellar ichthyosis (one form of autosomal recessive congenital ichthyosis). The neonate was born as a "collodion-baby" and he is the product of a maternal first cousin marriage. DNA sequencing of the coding exons of transglutiminase-1 (TGM1) gene revealed a novel missense (c.A1621C) mutation in exon 11. The mutation altered codon 541 from ACC into CCC thus changing the amino acid threonine into proline (p.T541P) and was predicted to be pathogenic. The presence of the mutation in both parents in heterozygous form and in the patient in homozygous form was further confirmed by PCR-restriction fragment length polymorphism (PCR-RFLP) designed specifically for the identified mutation. It is concluded that the T541P mutation is the cause of the congenital ichthyosis in the presented case and the parents were advised to undergo a PGD-IVF for embryo selection prior to their next pregnancy.