Pachyonychia Congenita: Clinical Features and Future Treatments.

Pachyonychia congenita (PC) is a rare, autosomal dominant inherited disorder of keratinization that is characterized by a triad of focal palmoplantar keratoderma, plantar pain, and hypertrophic nail dystrophy. It can be debilitating, causing significantly impaired mobility. PC is diagnosed clinically alongside identification of a heterozygous pathogenic mutation in one of five keratin genes: KRT6A, KRT6B, KRT6C, KRT16, or KRT17. Each keratin gene mutation is associated with a distinct clinical phenotype, with variable age of onset and additional features, which has allowed classification by genotype. Additional features include pilosebaceous cysts, follicular hyperkeratosis, natal teeth, oral leukokeratosis, hidradenitis suppurativa, itching, and neurovascular structures. Although classed as rare, the prevalence of PC is likely to be underestimated. There is no cure or specific treatment for PC at present. Current treatments are limited to conservative measures to reduce plantar friction and trauma, mechanical debridement, topical treatments, and treatments for associated features or complications, most commonly infection. However, through active research in collaboration with PC Project, a patient-advocacy group, and the International PC Research Registry, a global registry of PC patients, there are now many new potential therapeutic options on the horizon. This review summarizes the clinical features associated with PC and highlights the current and future treatment of its manifestations.

Risk-reducing surgery for individuals with cancer-predisposing germline pathogenic variants and no personal cancer history: a review of current UK guidelines.

Identifying healthy carriers of germline pathogenic variants in high penetrance cancer susceptibility genes offers the potential for risk-reducing surgery. The NHS England National Genomic Test Directory offers germline and somatic testing to patients with certain cancers or rare and inherited diseases, or, in some cases, to their relatives. This review summarises current UK guidelines for risk-reducing surgical interventions available for individuals with no personal history of cancer, who are determined to carry germline pathogenic variants. An electronic literature search of NICE guidelines and PubMed citable articles was performed. NICE guidelines are available for bilateral mastectomy and are currently in development for risk-reducing bilateral salpingo-oophorectomy. Guidelines developed with affiliation to, or through relevant British Surgical Societies or international consensus, are available for risk-reducing hysterectomy, polypectomy, gastrectomy, and thyroidectomy. There is a disparity in the development and distribution of national guidelines for interventions amongst tumour types. Whilst we are focusing on UK guidelines, we anticipate they will be relevant much more generally and so of interest to a wider audience including where there are no national guidelines to refer to. We suggest that, as genetic testing becomes rapidly more accessible, guideline development for interventions should be more closely aligned to those for testing.