Prevalence of filaggrin loss‐of‐function variants in Chilean population with and without atopic dermatitis

Abstract

Background Filaggrin (FLG) loss-of-function variants are major genetic risk factors for atopic dermatitis (AD), but these have not been studied in Latin American populations with and without AD. Methods FLG variants R501X and 2282del4 were genotyped in 275 Chilean adults with and without AD from the "Early origins of allergy and asthma" (ARIES) cohort and in 227 patients from an AD cohort based in Santiago, Chile.Results Among adults in the ARIES cohort, 3.3% were carriers of R501X and 2.9% of 2282del4 variants, all heterozygotes. In this cohort, 6.2% were FLG variant carriers: 11.1% of subjects reporting AD were carriers of FLG variants vs. 5.2% in those without AD (P = 0.13). In this first cohort, FLG variants were not significantly associated with asthma, allergic rhinitis, or food allergy. In the AD cohort, the prevalence of FLG variants was 7% for R501X, 2.2% for the 2282del4 variant, and 9.3% for the combined genotype. In this cohort, FLG variants were present in 15.5% of severe AD vs. 7.1% of mild-to-moderate AD subjects (P = 0.056). Evaluation of Chilean population from both cohorts combined (n = 502) revealed that FLG variants were not significantly associated with AD (OR = 1.92 [95% CI 0.95-3.9], P = 0.067) but were associated with asthma (OR = 2.16 [95% CI 1.02-4.56], P = 0.039).Conclusions This is the first study to evaluate FLG loss-of-function variants R501X and 2282del4 in Latin American population, revealing a similar prevalence of these FLG variant carriers to that of European populations. Among Chileans, FLG variants were significantly associated with asthma but not AD.

Ethnic and Racial Disparities in Clinical Manifestations of Atopic Dermatitis

“…A sizable number of people of European ancestry can be found in the populations of many Latin American countries. Chilean research found that 9.3 percent of their patient group had filaggrin mutations, which are commonly found in European individuals with AD [ 68 ]. Filaggrin and claudin-1, a protein involved in tight junctions, were both less abundant in the skin of Brazilian patients.…”

Atopic Dermatitis in Latin America: Considerations on Epidemiology, Clinical and Laboratory Features, Ethnic/Racial Variations, and Therapeutic Management

“…The population in some of the LA countries is predominantly of European origin. A study in Chile showed that filaggrin variants commonly seen in European patients with AD were observed in 9.3% of Chilean patients [12]. There was an impaired expression of filaggrin and claudin-1 (a tight junction protein), in the skin of Brazilian patients.…”

Atopic Dermatitis in Latin America: A Roadmap to Address Data Collection, Knowledge Gaps, and Challenges

“…Most information comes from survey-based studies, clinical studies in specific cities, 34 , 36 , 37 and other studies reporting AD treatment outcomes that provide data on clinical characteristics in certain LA countries. 27 , 38 , 39 A recent survey of filaggrin ( FLG ) gene loss-of-function mutations in Chile found that the 2 most common FLG gene variants (R501X and 2282del4) are present in 9.3% of Chilean patients, a similar rate to the European population, 40 whereas another study on FLG -2 gene polymorphisms in Brazilian patients found no relationship with AD. 41 …”