No Association of filaggrin copy number variation and atopic dermatitis risk in White and Black Americans.

Atopic dermatitis (AD) is a chronic, inflammatory skin condition with a multifactorial pathophysiology. The filaggrin gene (FLG) has particularly been implicated given loss of function (LoF) mutations in this gene lead to skin barrier dysfunction and such mutations can increase a patient's likelihood of developing AD. FLG has intragenic copy number variation (CNV), which impacts the total amount of filaggrin produced. Previous research reported a dose-dependent effect such that as amount of FLG increases, risk of AD decreases. To gain a better understanding, we evaluated FLG CNV in a large case-control study of Whites and Blacks with and without AD. The goal of our study was to determine whether FLG CNV has a dose-dependent effect on the risk of developing AD and to determine whether FLG CNV varies by race. The frequencies and odds ratios comparing a given CNV by race or race within those with AD did not significantly vary. It had been thought that FLG CNV might vary by race and represent an important association with AD in Black AD subjects. However, our work suggests that while there are racial differences with respect to CNV, these differences do not appear to explain AD risk.