Transglutaminase 1 gene mutations in a family with lamellar ichthyosis

Objective To detect the mutations of transglutaminase 1 (TGM1) gene in a family with lamellar ichthyosis. Methods The genomic DNA was extracted from the proband and his family members. All the encoding exons and adjacent splice sites of TGM1 gene were amplified by PCR. Mutation scanning was carried out via direct bi-directional DNA sequencing. Also the homology of TGM1 was analyzed. Results In the proband, there was a C504T mutation located at codon 142 (R142C) in exon 3 of TGM1 gene, and a nonsense mutation of C1122T located in exon 7, which caused a premature termination of R348X and a defective polypeptide truncated by 470 amino acids in C-terminus. A heterozygote of C504T mutation was carried by the proband′s father and a heterozygote of C1122T mutation in the proband′s mother. The missense mutation of R142C was found at the conservation region of TGM1 gene. Conclusion The mutations of R142C and R348X in TGM1 gene are present in the patient with lamellar ichthyosis.