Symmetrical dyschromatosis of extremities(DSH)

MedGen UID:: 96071
•Concept ID:: C0406775
•: Congenital Abnormality

Synonyms:	DSH; Dyschromatosis symmetrica hereditaria; Dyschromatosis symmetrica hereditaria 1; Familial reticulate acropigmentation of Dohi; Reticulate acropigmentation of Dohi; Symmetric dyschromatosis of the extremities
SNOMED CT:	Symmetrical dyschromatosis of extremities (239085000); Acropigmentation of Dohi (239085000); Reticulate acropigmentation of Dohi (239085000)
Modes of inheritance:	Autosomal dominant inheritance MedGen UID: 141047 •Concept ID: C0443147 • Intellectual Product Source: Orphanet A mode of inheritance that is observed for traits related to a gene encoded on one of the autosomes (i.e., the human chromosomes 1-22) in which a trait manifests in heterozygotes. In the context of medical genetics, an autosomal dominant disorder is caused when a single copy of the mutant allele is present. Males and females are affected equally, and can both transmit the disorder with a risk of 50% for each child of inheriting the mutant allele. Autosomal dominant inheritance (Orphanet)

Gene (location): Gene(s) directly associated with this condition or phenotype.	ADAR (1q21.3)

Monarch Initiative:	MONDO:0007483
OMIM®:	127400
Orphanet:	ORPHA41

Definition

Dyschromatosis symmetrica hereditaria (DSH), also called symmetric dyschromatosis of the extremities and symmetric or reticulate acropigmentation of Dohi (Komaya, 1924), is characterized by hyperpigmented and hypopigmented macules on the face and dorsal aspects of the extremities that appear in infancy or early childhood. DSH generally shows an autosomal dominant pattern of inheritance with high penetrance. The condition has been reported predominantly in Japanese and Chinese individuals. Aicardi-Goutieres syndrome-6 (AGS6; 615010) is an allelic disorder, and patients have been reported who exhibit features of both disorders. Review of Reticulate Pigment Disorders Muller et al. (2012) reviewed the spectrum of reticulate pigment disorders of the skin, tabulating all reported cases of patients with Dowling-Degos disease (see DDD1; 179850), reticulate acropigmentation of Kitamura (RAK; 615537), reticulate acropigmentation of Dohi (RAD), Galli-Galli disease (GGD), and Haber syndrome (HS). Of 82 cases, 26 (31.7%) were clinically diagnosed as DDD, 13 (15.9%) as RAD, 11 (13.4%) as GGD, 8 (9.8%) as RAK, and 8 (9.8%) as HS; in addition, 16 (19.5%) of the cases showed overlap between DDD and RAK. Muller et al. (2012) also published photographs of an affected individual exhibiting an overlap of clinical features of DDD, GGD, RAD, and RAK. The authors noted that in reticulate disorders of the skin, the main disease entity is DDD, with a subset of cases exhibiting acantholysis (GGD), facial erythema (HS), or an acral distribution (RAD; RAK). Muller et al. (2012) concluded that all reticulate pigment diseases of the skin are varying manifestations of a single entity. Genetic Heterogeneity of Reticulate Pigment Disorders For a discussion of genetic heterogeneity of reticulate pigment disorders, see 179850. [from OMIM]