TGM1 GenE

The TGM1 gene (TGM1 stands for Transglutaminase1) is a protein-coding gene located on chromosome 14q12. The protein encoded by this gene, transglutaminase-1, is a membrane protein that catalyzes the attachment of an alkyl group from an alkylamine to a glutamine residue of a protein, thus forming an alkylglutamine in the protein.

This protein alkylation leads to the cross-linking of proteins and the linking of polyamines with proteins. For example, the filaggrin monomers in the epidermis aggregate into keratin fibers through the catalytic activity of transglutaminase-1, which leads to cell flattening and the formation of corneocytes.

The TGM1 gene contains either one or two copies of a 22-nt repeat unit in its 3'-UTR.

Mutations in this gene are associated with:

• Autosomal recessive lamellar ichthyosis (LI) (see below Congenital autosomal recessive ichthyoses).
• Non-bullous congenital ichthyosiform erythroderma (NCIE) (Omim:242300).

Bathing suit ichthyosis(Omim:242300) is also associated with mutations in the TGM1 gene.

Related metabolic pathways include developmental biology and keratinization.

1. Benmously-Mlika R et al (2014) Bathing suit ichthyosis caused by a TGM1 mutation in a Tunisian child. Int J Dermatol 53:1478-1480.
2. Oji V et al (2006) Bathing suit ichthyosis is caused by transglutaminase-1 deficiency: evidence for a temperature-sensitive phenotype. Hum Mol Genet 15:3083-3097.