MBTPS2 mutation in a British pedigree with keratosis follicularis spinulosa decalvans.

Keratosis follicularis spinulosa decalvans (KFSD; OMIM 308800) is an X-linked disorder characterized by widespread hyperkeratotic follicular papules (including keratosis pilaris-like lesions), facial erythema, hypotrichosis and scarring alopecia. KFSD results from mutations in the MBTPS2 gene. Mutations in this gene also underlie ichthyosis follicularis, alopecia and photophobia syndrome. We report a British pedigree with KFSD resulting from the mutation p.Asn508Ser. This particular mutation has been reported in three other pedigrees with KFSD (Dutch, American, British) and is the only pathogenic mutation reported in this disorder to date. However, the same mutation has also been reported in a Chinese pedigree with IFAP syndrome, highlighting the clinical heterogeneity and overlapping molecular pathology of these two disorders.