A novel KRT86 mutation in a Turkish family with monilethrix, and identification of maternal mosaicism.
Clin Exp Dermatol 2015;
40:781-5. [PMID:
25809918 DOI:
10.1111/ced.12631]
[Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/02/2014] [Indexed: 11/29/2022]
Abstract
BACKGROUND
Monilethrix is a rare monogenic dystrophic hair loss disorder with high levels of intrafamilial and interfamilial variability. It is characterized by diffuse occipital or temporal alopecia, hair fragility and follicular hyperkeratosis of the occipital region. Mutations in the keratin genes KRT81, KRT83 and KRT86 lead to autosomal dominant monilethrix, whereas mutations in the desmoglein 4 gene (DSG4) cause an autosomal recessive form.
AIM
To identify the mutation in a consanguineous Turkish family with three affected children and apparently unaffected parents.
METHODS
Sequencing analysis of the genes DSG4 and KRT86 was performed. SNaPshot analysis was conducted to quantify the proportion of cells carrying the KRT86 mutation and to confirm maternal mosaicism of KRT86.
RESULTS
No pathogenic mutation was found by sequencing analysis of DSG4; however, analysis of KRT86 revealed a novel mutation, c.1231G>T;p.Glu411*, in exon 7 in the three affected children and their mother. The mutation signal was weaker in the mother than in the three siblings, and SNaPshot analysis revealed substantial mutation-level variation between the children and their mother.
CONCLUSIONS
Our results extend the spectrum of KRT86 mutations and indicate KRT86 mosaicism in the family examined. This study is the first, to our knowledge, to describe mosaicism for a monogenic hair loss disorder, and suggests that mosaicism leads to a mild manifestation of monilethrix.
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