Mutations in MBTPS2 have been reported to cause a broad phenotypic spectrum of 
X-linked genodermatoses, including IFAP (ichthyosis follicularis; atrichia and 
photophobia) syndrome (OMIM 308205) with or without BRESHECK (brain anomalies, 
retardation of mentality and growth, ectodermal dysplasia, skeletal 
malformations, Hirschsprung disease, ear deformity and deafness, eye hypoplasia, 
cleft palate, cryptorchidism, and kidney dysplasia/hypoplasia) syndrome, 
keratosis follicularis spinulosa decalvans (KFSD; OMIM 308800) and an X-linked 
form of Olmsted syndrome. We report a recurrent intronic mutation in MBTPS2 
(c.671-9T>G) in a Chinese patient with the typical triad of IFAP syndrome (i.e. 
ichthyosis, atrichia and photophobia), along with pachyonychia, palmoplantar and 
periorificial keratoderma, which were reminiscent of Olmsted syndrome. 
Interestingly, this mutation was previously reported in two cases of IFAP 
without keratoderma, which suggests clinical heterogeneicity of the same 
mutation in MBTPS2. The concomitance of Olmsted syndrome-like features in this 
patient with IFAP may challenge the existence of the X-linked form of Olmsted 
syndrome as an independent condition.