A novel mutation in MBTPS2 causes a broad phenotypic spectrum of ichthyosis follicularis, atrichia, and photophobia syndrome in a large Chinese family.

BACKGROUND: Ichthyosis follicularis, atrichia, and photophobia (IFAP) syndrome is a rare congenital disorder. Missense mutations in the membrane-bound transcription factor protease, site 2 (MBTPS2) gene have recently been identified in patients with IFAP. OBJECTIVE: To determine whether Chinese patients with IFAP have MBTPS2 mutations. METHODS: We observed a large IFAP pedigree of 5 generations in a Chinese family and performed MBTPS2 molecular analysis. RESULTS: The male proband was severely affected. He presented with hyperextensibility of the interphalangeal joints of the fingers in addition to previously reported clinical manifestations. Clinically affected female patients had hairless patches on the scalp, ichthyosiform skin changes, hypotrichosis, hyperkeratosis, nail dystrophy, and brown scaly plaques, some of which were arranged in a linear pattern following the lines of Blaschko. Molecular analysis identified a novel missense mutation in exon 11 and confirmed cosegregation of the missense mutation with the disease in this family. LIMITATIONS: It is unclear whether hyperextensibility of the fingers was nosologically related to IFAP syndrome or was a coincidental finding. CONCLUSION: This report provides further evidence for the genetic basis of IFAP syndrome and enlarges the phenotypic spectrum and number of MBTPS2 mutations. We confirm that MBTPS2 mutations cause IFAP in patients of Chinese origin.

Pityriasis rotunda.

Pityriasis rotunda is an uncommon cutaneous disorder consisting of asymptomatic, strikingly circular, scaly lesions on the trunk and extremities, with the histologic appearance of ichthyosis vulgaris. Previous cases have been described in Japanese, South African, and West Indian persons, usually in association with an underlying serious systemic disease. A case of pityriasis rotunda in a 32-year-old black man in whom no diagnosable disorder could be demonstrated is presented.

Clinico-epidemiological profile of ichthyosis in south Indian patients.

A high frequency rate of hereditary ichthyosis (141.89 per 1000) was detected in a 1029 member South Indian study population selected at random from the skin outpatients of a teaching hospital. An age and sex matched control population screened from the medical and pediatric outpatients of the same institute recorded the incidence of ichthyosis vulgaris as 150 per 1000 population which is even higher.