Dyschromatosis symmetrica hereditaria L81.8

Rare, autosomal-dominantly inherited, small-spotted, partially leukodermic, symmetric, reticular hyperpigmentation on the dorsum of the hands and feet and on the face.

The disease manifests in early childhood.

Neurologic disturbances have also been described.

A closely related disorder also described in European countries is Aicardi-Goutières syndrome. Mutations in the ADAR gene have been described in both diseases. However, Aicardi-Goutières syndrome, in contrast to dyschromatosis symmetrica hereditaria, is associated with chilblain lesions. Exceptions have been described (Kono M et al. 2018).

So far only observed with Chinese, Japanese and Koreans.

Mutations of the ADAR gene (adenosine deaminase RNA-specific gene), which is localized on chromosome 1q21.3 and which encodes a deaminase that converts adenosine to inosine. This enzyme is localized in many tissues, including lymphocytes and lung. Furthermore, RNA-specific adenosine deaminase plays a significant role in pigment formation (Kono M et al. 2011).

Several mutations have been described, and the different genotypes do not appear to differ phenotypically (Hu W et al. 2019; Kobayashi T et al. 2018).

Manifestation in early childhood.

Normal histopathological epidermis relief. Hyperpigmentation of the basal keratinocytes. In the hypopigmented areas the epidermal pigmentation is reduced. Number of melanocytes is not increased.

Dyschromatosis symmetrica hereditaria (DSH) and Reticulate Acropigmentation of Kitamura (RAK) seem to have a different genotype with largely identical phenotype. In RAK, mutations in the ADAM1 gene have been described (Kono M et al. 2019).

1. Dutta A et al (2014) Dyschromatosis symmetrica hereditaria with neurological abnormalities. Indian J Dermatol Venereol Leprol 80:549-551.
2. Gaiewski CB et al (2014) Dyschromatosis symmetrica hereditaria of late onset? Case Rep Dermatol Med doi: 10.1155/2014/63953
3. Hu W et al (2019) Four novel mutations of ADAR1 in Chinese patients with dyschromatosis symmetrica hereditaria. Indian J Dermatol Venereol Leprol 85:69-73.
4. Kobayashi T et al (2018) Analysis of genotype/phenotype correlations in Japanese patients with dyschromatosis symmetrica hereditaria. Nagoya J Med Sci. 80:267-277 .
5. Kono M et al (2011) Four novel ADAR1 gene mutations in patients with dyschromatosis symmetrica hereditaria. J Dermatol 39:819-821.
6. Kono M et al (2018) Dyschromatosis symmetrica hereditaria with chilblains due to a novel two-amino-acid deletion in the double-stranded RNA-binding domain of ADAR1. J Eur Acad Dermatol Venereol 32:e394-e396.
7. Kono M et al (2019) Dyschromatosis symmetrica hereditaria and reticulate acropigmentation of Kitamura: An update. J Dermatol Sci 93:75-81.
8. Lee YB, Lee SB, Kim SJ, Park SM, Ko HR, Kim JW, Yu DS. A frameshift mutation in the ADAR gene in a Korean family with dyschromatosis symmetrica hereditaria. Eur J Dermatol 24:693-695.

9. Peng A et al. (2013) Dyschromatosis symmetrica hereditaria: A retrospective case series and literature review Dermatologica Sinica 19-24.