Introduction In this chapter, a number of genodermatoses are discussed that are not covered in other chapters of this textbook ( Table 63.1 ). Table 63.1 Genodermatoses. See also Chapter 55 . GENODERMATOSES Hereditary connective tissue disorders ( Chs 64…
Key features ▪ Mosaicism for genes expressed in the skin presents as a patchy distribution of affected and unaffected skin ▪ The classical pattern follows the lines of Blaschko but varies according to cell type and timing of mosaicism ▪…
Introduction Neurofibromatosis (NF) and tuberous sclerosis (TS) are neurocutaneous disorders, or phakomatoses. They are characterized by cutaneous lesions as well as peripheral and/or central nervous system neoplasms. Like most hereditary cancer syndromes, NF and TS are autosomal dominant in inheritance.…
Introduction Primary immunodeficiencies represent a heterogeneous group of inherited disorders characterized by immune system defects that result in susceptibility to infections as well as additional manifestations such as autoimmunity, allergy, and malignancy. The molecular bases have been defined for >200…
Darier Disease Synonyms ▪ Darier–White disease ▪ Keratosis follicularis ▪ Dyskeratosis follicularis Key features ▪ Autosomal dominant disorder in which mutations in the ATP2A2 gene result in dysfunction of an endoplasmic reticulum Ca 2+ ATPase (SERCA2), thus interfering with intracellular…
Key features ▪ Palmoplantar keratodermas can be inherited or acquired ▪ The three major patterns of involvement are diffuse, focal, and punctate ▪ The clinical presentation may be different on the hands and feet, e.g. diffuse on the soles and…
Key features ▪ Ichthyoses and erythrokeratodermas are heterogeneous groups of disorders of cornification ▪ Ichthyoses are characterized by scaling of the skin in a widespread distribution ▪ Erythrokeratodermas feature discrete areas of erythema and hyperkeratosis, usually without substantial scale ▪…
Key features ▪ The epidermis functions as a barrier that provides protection against harmful substances and water loss ▪ Through a complex terminal differentiation program, the progeny of epidermal stem cells undergo molecular and biochemical changes that generate the morphologically…
Key features ▪ Advances in molecular technology have led to elucidation of the genetic bases of many single-gene inherited and mosaic skin disorders, greatly improving our understanding of these conditions ▪ McKusick's Online Mendelian Inheritance in Man (OMIM) database provides…
Introduction The completion of the human genome sequence, with an estimated size of 3.2 gigabases (Gb) and containing ~20 000–25 000 genes , represents a powerful tool in medicine that facilitates the identification of disease-associated genes. Detailed information on human sequence variation…