Laboratory of Molecular and Cell Biology, Istituto Dermopatico dell'Immacolata-IRCCS, Rome, Italy.
Division of Medical Genetics, Casa Sollievo della Sofferenza-IRCCS, San Giovanni Rotondo, Foggia, Italy.
J Eur Acad Dermatol Venereol. 2018 May;32(5):704-719. doi: 10.1111/jdv.14902. Epub 2018 Mar 24.
The term palmoplantar keratoderma (PPK) indicates any form of persistent thickening of the epidermis of palms and soles and includes genetic as well as acquired conditions. We review the nosology of hereditary PPKs that comprise an increasing number of entities with different prognoses, and a multitude of associated cutaneous and extracutaneous features. On the basis of the phenotypic consequences of the underlying genetic defect, hereditary PPKs may be divided into the following: (i) non-syndromic, isolated PPKs, which are characterized by a unique or predominant palmoplantar involvement; (ii) non-syndromic PPKs with additional distinctive cutaneous and adnexal manifestations, here named complex PPKs; (iii) syndromic PPKs, in which PPK is associated with specific extracutaneous manifestations. To date, the diagnosis of the different hereditary PPKs is based mainly on clinical history and features combined with histopathological findings. In recent years, the exponentially increasing use of next-generation sequencing technologies has led to the identification of several novel disease genes, and thus substantially contributed to elucidate the molecular basis of such a heterogeneous group of disorders. Here, we focus on hereditary non-syndromic isolated and complex PPKs. Syndromic PPKs are reviewed in the second part of this 2-part article, where other well-defined genetic diseases, which may present PPK among their phenotypic manifestations, are also listed and diagnostic and therapeutic approaches for PPKs are summarized.
掌跖角化过度症（PPK）一词表示手掌和脚底表皮持续增厚的任何形式，包括遗传和获得性疾病。我们回顾了遗传性 PPK 的分类学，其中包括越来越多具有不同预后的实体，以及多种相关的皮肤和皮肤外特征。根据潜在遗传缺陷的表型后果，遗传性 PPK 可分为以下几类：（i）非综合征性孤立性 PPK，其特征为独特或主要累及手掌和足底；（ii）非综合征性 PPK 伴额外独特的皮肤和附属器表现，此处命名为复杂 PPK；（iii）综合征性 PPK，其中 PPK 与特定的皮肤外表现相关。迄今为止，不同遗传性 PPK 的诊断主要基于临床病史和特征，结合组织病理学发现。近年来，下一代测序技术的使用呈指数级增长，已确定了几个新的疾病基因，从而大大阐明了这组异质性疾病的分子基础。在这里，我们重点关注遗传性非综合征性孤立性和复杂性 PPK。综合征性 PPK 将在这篇 2 部分文章的第二部分中进行综述，其中还列出了其他明确的遗传疾病，这些疾病可能在其表型表现中出现 PPK，并总结了 PPK 的诊断和治疗方法。
