RESUMO
A 37-year-old Japanese male presented to us with persistent asteatotic skin with mild erythema on the trunk and extremities. Skin biopsy from the left knee showed marked epidermal acanthosis and hyperkeratosis, and milder granular degeneration. Ultrastructural analysis revealed clumping of the keratin filaments within suprabasal keratinocytes of the epidermis. Following direct sequencing, we found a single nucleotide substitution in one allele at the residue position 466 of the 1A rod domain segment (CGC to TGC, arginine to cysteine; R156C) in keratin 10. Clinical manifestations and molecular analysis indicated that R156C mutation in keratin 10 gene (KRT10) causes a mild form of epidermolytic hyperkeratosis (EHK) in the presented case.
Assuntos
Substituição de Aminoácidos/genética , Hiperceratose Epidermolítica/genética , Queratina-10/genética , Mutação Puntual , Adulto , Códon , Análise Mutacional de DNA , Humanos , Hiperceratose Epidermolítica/patologia , Hiperceratose Epidermolítica/ultraestrutura , Masculino , Pele/patologia , Pele/ultraestruturaRESUMO
We report a case of diffuse plane normolipemic xanthomatosis (DPNX) which showed poorly demarcated, uncommon, yellow macules symmetrically distributed on the nape, axillae and inguinal folds accompanied by severe, persistent itching. Histopathological and ultrastructural studies of skin biopsy specimens revealed the existence of some foamy cells and the deposition of neutral fat in the upper papillary dermis. Laboratory investigations and bone marrow aspirate smears showed that our patient had myelodysplastic syndrome (MDS) associated with pancytopenia and monoclonal gammopathy of undetermined significance. Because our patient had neither a malignant hematological disorder nor a severe systemic disease, monoclonal gammopathy might explain the pathogenesis of DPNX in the present case.
