Wei-Wei Ge,1 Zai-Ming Chen,1 Meng-Wei Chou,2 Ferina Ismail,3 Guang Chen,1 Li-Ming Wu,4 Jian-Qiang Yang2 

1Department of Dermatology, Taizhou Second People’s Hospital (Mental Health Center Affiliated to Taizhou University School of Medicine), Taizhou University, Taizhou, Zhejiang, 318000, People’s Republic of China; 2Department of Dermatology, The First Affiliated Hospital of Huzhou University, Huzhou, Zhejiang, People’s Republic of China; 3Department of Dermatology, Royal Free Hospital, London, England; 4Department of Dermatology, the First Hangzhou People’s Hospital, Hangzhou, Zhejiang, People’s Republic of China

Correspondence: Guang Chen; Jian-qiang Yang, Email misschenguang75@163.com; yjq@zjhu.edu.cn

Abstract: Pachyonychia congenita (PC) is a group of rare hereditary disorders, characterised by hypertrophic nails and palmoplantar keratoderma (PPK), particularly localised to the pressure areas of the feet. At a molecular level, it is caused by mutations in genes encoding KRT6A, KRT6B, KRT6C, KRT16, or KRT17. To identify the underlying gene mutation in a Chinese family with PC presenting with disabling palmoplantar keratoderma and subsequent associated acral melanoma. Genomic DNA was extracted from peripheral blood samples of three available individuals in the Chinese family, which included the patient and his two unaffected sisters. The index patient presented with severe palmoplantar keratoderma as well as a newly diagnosed acral malignant melanoma (MM). Whole-exome sequencing (WES) was carried out with amplification of exon 1 of KRT16 by polymerase chain reaction (PCR). PCR products were then sequenced to identify potential mutations. We identified the proline substitution mutation p.Arg127Pro (c.380G>C) in our patient’s 1A domain of KRT16. The same mutation was not found in his sisters or unrelated healthy controls. The mutation (p.Arg127Pro (c.380G>C)) in KRT16 has been reported in Dutch patients with PC. However, it is the first such report of a patient with a PC of Chinese origin. In addition, the acral MM occurred under the background of genetic PPK caused by KRT16 mutation in this patient.

Keywords: pachyonychia congenita, Chinese patient, acral melanoma, mutation of gene