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Heterozygous frameshift mutation in keratin 5 in a family with G alli– G alli disease
Author(s) -
Reisenauer A.K.,
Wordingham S.V.,
York J.,
Kokkonen E.W.J.,
Mclean W.H.I.,
Wilson N.J.,
Smith F.J.D.
Publication year - 2014
Publication title -
british journal of dermatology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.304
H-Index - 179
eISSN - 1365-2133
pISSN - 0007-0963
DOI - 10.1111/bjd.12813
Subject(s) - frameshift mutation , disease , mutation , medicine , genetics , biology , gene
Summary Background Reticulate pigmentary disorders include the rare autosomal dominant G alli– G alli disease ( GGD ) and D owling– D egos disease (DDD). Clinical diagnosis between some of the subtypes can be difficult due to a degree of overlap between clinical features, therefore analysis at the molecular level may be necessary to confirm the diagnosis. Objectives To identify the underlying genetic defect in a 48‐year‐old A sian‐ A merican woman with a clinical diagnosis of GGD . Methods Histological analysis was performed on a skin biopsy using haematoxylin–eosin staining. KRT 5 (the gene encoding keratin 5) was amplified from genomic DNA and directly sequenced. Results The patient had a history of pruritus and hyperpigmented erythematous macules and thin papules along the flexor surfaces of her arms, her upper back and neck, axillae and inframammary areas. Hypopigmented macules were seen among the hyperpigmentation. A heterozygous 1‐bp insertion mutation in KRT 5 (c.38dup G ; p. S er14 G lnfs T er3) was identified in the proband. This mutation occurs within the head domain of the keratin 5 protein leading to a frameshift and premature stop codon. Conclusions From the histological findings and mutation analysis the individual was identified as having GGD due to haploinsufficiency of keratin 5.