Filaggrin-2 variation is associated with more persistent atopic dermatitis in African American subjects

Atopic dermatitis (AD) is a common skin disease characterized by recurrent episodes of itching. Genetic variation associated with the persistence of AD has not been described for African American subjects.

We sought to evaluate genetic variation of filaggrin-2 (FLG2) in African American subjects with AD.

We evaluated a multiyear prospective cohort study of African American children with AD with respect to FLG2 variation based on whole-exome sequencing, followed by a targeted analysis. We ultimately evaluated the association of rs12568784 and rs16833974 with respect to the persistence of AD symptoms over time.

Whole-exome analysis was conducted on 60 subjects, revealing a premature stop codon in exon 3 at S2377X (rs12568784) and X2392S (rs150529054) and a large exon 3 deletion mutation, Q2053del224. On the basis of a priori criteria, we then studied rs12568784, rs16833974 (H1249R), and Q2053del224. We noted that patients with S2377X (odds ratio [OR], 0.44; 95% CI, 0.25-0.46) and H1249R (OR, 0.23; 05% CI, 0.12-0.46) were significantly less likely to be free of symptoms of AD, and Q2053del224 (OR, 0.54; 95% CI, 0.16-1.80) trended toward this outcome. S2377X and H1249R were in high linkage disequilibrium (D' = 0.95).

In an African American cohort with AD, FLG2 mutations were associated with more persistent AD. This is the first finding of genetic variation of a skin barrier protein in subjects of African ancestry with AD.