Molecular analysis of the FLG gene in this study showed nine null and one unclassified mutation in 13 of 81 Korean patients with atopic dermatitis (AD): five novel null mutations (i.e. p.S1405*, c.5671_5672delinsTA, p.W1947*, p.G2025* and p.E3070*); four reported null mutations (i.e. c.3321delA, p.S1515*, p.S3296* and p.K4022*); and one unclassified mutation (i.e. c.306delAAAGCACAG).