1. ¹Institute of Human Genetics, University of Bonn, Bonn, Germany
2. ²Institute for Medical Biometry, Informatics and Epidemiology, University of Bonn, Bonn, Germany
3. ³Department of Dermatology, University of Düsseldorf, Düsseldorf, Germany
4. ⁴Department of Dermatology, University of Bonn, Bonn, Germany
5. ⁵Department of Dermatology, University of Antwerp, Antwerp, Belgium
6. ⁶Department of Dermatology, University of Gent, Gent, Belgium
7. ⁷Department of Genomics, Life and Brain Center, University of Bonn, Bonn, Germany
8. ⁸Division of Genetic Epidemiology in Psychiatry, Central Institute of Mental Health, Mannheim, Germany
9. ⁹Hair and Nail, Bonn, Germany
10. ¹⁰Department of Medical Genetics, University of Antwerp, Antwerp, Belgium

Correspondence: Dr Regina C. Betz, Institute of Human Genetics, University of Bonn, Wilhelmstrasse 31, Bonn D-53111, Germany. E-mail: regina.betz@uni-bonn.de

Received 24 October 2006; Revised 5 April 2007; Accepted 20 April 2007; Published online 21 June 2007.

Abstract

Alopecia areata (AA) is a common dermatological disease, which affects nearly 2% of the general population. Association of AA with atopic disease has been repeatedly reported. Loss-of-function mutations in the filaggrin gene (FLG) may be considered as promising candidates in AA, as they have been observed to be a strong risk factor in atopic dermatitis. The FLG mutations R501X and 2282del4 were genotyped in a large sample of AA patients (n=449) and controls (n=473). Although no significant association was observed in the patient sample overall, FLG mutations were significantly associated with the presence of atopic dermatitis among AA patients. Furthermore, the presence of FLG mutations had a strong impact on the clinical course of AA in comorbid patients. For example, 19 of the 22 mutation carriers among AA patients with atopic dermatitis showed a severe form of the disease (P=0.003; odds ratio (OR)=5.47 (95% confidence interval (CI): 1.59–18.76)). In conclusion, our data suggest that when AA occurs in conjunction with FLG-associated atopic disorder, the clinical presentation of AA may be more severe.