Filaggrin, Ichthyosis, and Atopy Revisited

In landmark discoveries in 2006, researchers found that mutations in the gene coding for filaggrin cause ichthyosis vulgaris (Journal Watch Dermatology Mar 28 2006) and atopic dermatitis and asthma (Journal Watch Dermatology Apr 25 2006). Ichthyosis is more severe in homozygous carriers than in heterozygous carriers, but even heterozygotes have deficient and possibly defective filaggrin. The gene is located in the epidermal differentiation complex on chromosome 1q21. Because exon 3 encodes 10 to 12 full tandem repeats of the filaggrin protein, further analysis of the gene has been difficult.

Now we have more data. Investigators used a new series of primers that overlapped the entire exon. They found 15 variant nonsense or frame-shift mutatio…