Department of Dermatology and Allergy Centre, J.B. Winsløws Vej 4 , Entrance 142, 5000, Odense C, Denmark.
Department of Clinical Genetics, J.B. Winsløws Vej 4, Entrance 24, 5000, Odense C, Denmark.
Orphanet J Rare Dis. 2018 Mar 5;13(1):39. doi: 10.1186/s13023-018-0778-6.
Pigmentary mosaicism is a term that describes varied patterns of pigmentation in the skin caused by genetic heterogeneity of the skin cells. In a substantial number of cases, pigmentary mosaicism is observed alongside extracutaneous abnormalities typically involving the central nervous system and the musculoskeletal system. We have compiled information on previous cases of pigmentary mosaicism aiming to optimize the handling of patients with this condition. Our study is based on a database search in PubMed containing papers written in English, published between January 1985 and April 2017. The search yielded 174 relevant and original articles, detailing a total number of 651 patients.
Forty-three percent of the patients exhibited hyperpigmentation, 50% exhibited hypopigmentation, and 7% exhibited a combination of hyperpigmentation and hypopigmentation. Fifty-six percent exhibited extracutaneous manifestations. The presence of extracutaneous manifestations in each subgroup varied: 32% in patients with hyperpigmentation, 73% in patients with hypopigmentation, and 83% in patients with combined hyperpigmentation and hypopigmentation. Cytogenetic analyses were performed in 40% of the patients: peripheral blood lymphocytes were analysed in 48%, skin fibroblasts in 5%, and both analyses were performed in 40%. In the remaining 7% the analysed cell type was not specified. Forty-two percent of the tested patients exhibited an abnormal karyotype; 84% of those presented a mosaic state and 16% presented a non-mosaic structural or numerical abnormality. In patients with extracutaneous manifestations, 43% of the cytogenetically tested patients exhibited an abnormal karyotype. In patients without extracutaneous manifestations, 32% of the cytogenetically tested patients exhibited an abnormal karyotype.
We recommend a uniform parlance when describing the clinical picture of pigmentary mosaicism. Based on the results found in this review, we recommend that patients with pigmentary mosaicism undergo physical examination, highlighting with Wood's light, and karyotyping from peripheral blood lymphocytes and skin fibroblasts. It is important that both patients with and without extracutaneous manifestations are tested cytogenetically, as the frequency of abnormal karyotype in the two groups seems comparable. According to the results only a minor part of patients, especially those without extracutaneous manifestations, are tested today reflecting a need for change in clinical practice.
色素镶嵌症是一个术语，用于描述由于皮肤细胞的遗传异质性导致的皮肤色素分布不均的各种模式。在大量情况下，色素镶嵌症与典型涉及中枢神经系统和肌肉骨骼系统的皮肤外异常同时存在。我们已经收集了有关先前色素镶嵌症病例的信息，旨在优化对这种情况患者的处理。我们的研究基于在 PubMed 中进行的英文文献数据库搜索，该搜索涵盖了 1985 年 1 月至 2017 年 4 月期间发表的论文。搜索结果得到 174 篇相关的原始文章，详细描述了 651 例患者。
43%的患者表现为色素沉着过度，50%表现为色素减退，7%表现为色素沉着过度和色素减退的混合。56%的患者存在皮肤外表现。各亚组中皮肤外表现的存在情况如下：色素沉着过度患者中为 32%，色素减退患者中为 73%，色素沉着过度和色素减退混合患者中为 83%。对 40%的患者进行了细胞遗传学分析：外周血淋巴细胞分析占 48%，皮肤成纤维细胞分析占 5%，两者均分析的占 40%。在其余 7%的患者中，未具体说明分析的细胞类型。42%的受检患者表现出异常核型；84%的患者呈现镶嵌状态，16%的患者呈现非镶嵌结构性或数量性异常。在有皮肤外表现的患者中，43%的细胞遗传学检测患者表现出异常核型。在没有皮肤外表现的患者中，32%的细胞遗传学检测患者表现出异常核型。
我们建议在描述色素镶嵌症的临床特征时使用统一的术语。根据本综述的结果，我们建议色素镶嵌症患者进行体格检查，用伍德灯强调，并从外周血淋巴细胞和皮肤成纤维细胞进行核型分析。重要的是，无论是有皮肤外表现的患者还是没有皮肤外表现的患者都要进行细胞遗传学检查，因为两组异常核型的频率似乎相当。根据结果，只有一小部分患者，特别是那些没有皮肤外表现的患者，今天接受了检查，这反映了临床实践需要改变。
