Genetics of syndromic and non‐syndromic hereditary nail disorders

Abstract

The nail is a unique epithelial skin appendage made up of a fully keratinized nail plate. The nail can be affected in several systemic illnesses, dermatological diseases, and inherited nail disorders. Nail dystrophies can present as isolated disorders or as a part of syndromes. Substantial progress has been achieved in the management and diagnosis of nail diseases; however, not much is known about the underlying molecular controls of nail growth. The homeostasis and development of the nail appendage depend on the intricate interactions between the epidermis and underlying mesenchyme, and comprise different signaling pathways such as the WNT signaling pathway. Digit-tip regeneration in mice and humans has been a known fact for the past six decades; however, only recently the underlying biological mechanisms by which the nail organ achieves digit regeneration have been elucidated. Moreover, significant progress has been made in identifying nail stem cells and localizing stem cell niches in the nail unit. More fascinating, however, is the role they play in orchestrating the processes that lead to the regeneration of the digit. Further elucidating the role of nail stem cells and the signaling pathways driving epithelial-mesenchymal interactions in the nail unit might contribute to the development of novel therapeutic tools for amputees.

What do we learn from dystrophic epidermolysis bullosa, nails only? Idiopathic nail dystrophy may harbor a COL7A1 mutation as the underlying cause

“…Although onychomycosis is the most common nail disorder and accounts for 50% of all nail diseases, the other 50% are other than fungal infections, including neoplastic, traumatic or congenital infections, or related to systemic disease 4 . Inherited nail disorders can present as isolated disorders or as a part of ectodermal syndromes involving the hair, teeth and sweat glands 5 . Nail disorder, non‐syndromic congenital (Online Mendelian Inheritance in Man) refers to a class of hereditary nail disorders without other clinical manifestations.…”

“…4 Inherited nail disorders can present as isolated disorders or as a part of ectodermal syndromes involving the hair, teeth and sweat glands. 5 Nail disorder, non-syndromic congenital (Online Mendelian Inheritance in Man) refers to a class of hereditary nail disorders without other clinical manifestations. Currently, it involves 10 different types.…”

27TH Fondation René Touraine Annual SCIENTIFIC MEETING 2019

“…In contrast, some areas of skin appendage research have remained, with a few notable exceptions, relatively stagnant compared to where they stood 5‐10 years before, such as the biology and pathophysiology of eccrine and apocrine sweat glands, and the nail apparatus as well as the neuroendocrinology and neurobiology of hair follicles . Yet, recent methodological advances, for example in the intravital visualization of human eccrine sweat glands for microdissection and organ culture or in the 3D reconstruction and measurement of sweat production by fat‐suppressed proton density‐weighted MRI make us run out of excuses for not having dissected the physiology and molecular pathobiology of these remarkable skin appendages with the same attention to detail that HF and SG have long enjoyed.…”