Novel Filaggrin Variants Are Associated with Ichthyosis Vulgaris in Mexicans.

BACKGROUND/OBJECTIVE: Ichthyosis vulgaris (IV) is a genodermatosis caused by heterozygous, homozygous, or compound heterozygous variants in the filaggrin () gene on chromosome 1q21, which also predispose individuals to atopic dermatitis. Its incidence is 1 in 80-250 children. The phenotypic characteristics include palmar hyperlinearity, keratosis pilaris, and a fine scale that is most prominent over the lower abdomen, arms, and legs. Our objective was to study the genetic variants in the gene and their associations in patients with ichthyosis vulgaris.

MATERIAL AND METHODS

Here, we studied eighteen Mexican sporadic cases and four family members with IV. Steroid sulfatase (STS) enzymatic activity, polymerase chain reaction (PCR), and direct sequencing on the gene were conducted.

RESULTS

We found the recurrent heterozygous variant R501* in fifteen sporadic cases, while the other three sporadic cases showed four novel (p.Q2123R, p.H2118R, p.D2120E, p.S3970L) variants and one reported (p.Y2119H) variant; members of family 1 and 2 presented novel homozygous and heterozygous (p.S1482Y, p.P2144S) variants.

CONCLUSIONS

This study added to the novel pathogenic variants in patients with IV and showed that the stop mutations (p.R501*) in the Mexican population are the most prevalent.