屈侧网状色素沉着一家系调查及KRT5基因突变检测

Reticulate pigmented anomaly of the flexures： a family survey and mutation analysis of KRT5 gene

目的探讨屈侧网状色素沉着一家系患者的临床表现及其致病原因。方法对该家系进行调查，详细记录每例患者的临床表现，观察先证者的组织病理和超微结构，并对家系中3例患者的KRT5基因进行突变检测。结果该家系所有患者均表现为皱褶部网状色素沉着，背部及腹部表现特发性点状白斑。组织病理学和超微结构观察发现，表皮色素增加，角质形成细胞内有大量黑素颗粒，黑素细胞的数目无明显变化。KRT5基因突变检测，未发现突变。结论首次报道皱褶部网状色素沉着伴特发性白斑，家系中未检测到KRT5基因的突变，表明该病可能存在其他的致病基因。

Objective To observe clinical features and identify causative genes of reticulate pigmented anomaly of the flexures in a pedigree. Methods A survey was conducted in a pedigree with reticulate pigmented anomaly of the flexures. Clinical manifestations were recorded in details for each patient in this pedigree. Tissue specimen was obtained from the proband for histopathological examination and ultrastructural observation. Mutation scanning was carried out by PCR and direct sequencing in 3 patients in the family. Results All the patients in this pedigree presented with reticular pigmentation of the flexures and idiopathic guttate hypomelanosis on the abdomen and back. Histopathological and uhrastructural study revealed epidermal hyperpigmentation with an increase in melanin content in epidermal keratinocytes but no changes in the number of melanocytes. No mutation was found in the KRT5 gene in this family. Conclusions This is the first case report of reticulate pigmented anomaly of the flexures associated with idiopathic guttate hypomelanosis. No mutation is identified in the KRT5 gene of patients with reticulate pigmented anomaly of the flexures in this family, indicating the existence of other causative genes.