Preferred Label : Reticulate acropigmentation of kitamura;
Symbol : RAK;
CISMeF acronym : RAK; RPK;
Type : Phenotype, molecular basis known;
Alternative titles and symbols : RPK; Reticulate pigmentation of kitamura; Kitamura reticulate acropigmentation; Acropigmentatio reticularis;
Description : Reticulate acropigmentation of Kitamura (RAK) is a rare pigmentary disorder that usually
shows an autosomal dominant pattern of inheritance with high penetrance. Typical features
include reticulate, slightly depressed, sharply demarcated brown macules without hypopigmentation,
affecting the dorsa of the hands and feet in the first or second decade of life. The
macules gradually darken and extend to the proximal regions of the extremities; progression
of the eruptions stops in middle age. The increased pigmentation is found on the flexor
aspects of the wrists, neck, patella, and olecranon. Other features include breaks
in the epidermal ridges on the palms and fingers, palmoplantar pits, partial alopecia,
and occasionally plantar keratoderma. Histopathologically, the brown macules show
pigmentation in the tip of rete ridges with thinning of the epidermis, elongation
and thinning of the rete ridges, and slight hyperkeratosis without parakeratosis.
Only a few inflammatory cell infiltrates and no incontinentia pigmenti are seen in
the dermis (summary by Kono et al., 2013). - 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), reticulate acropigmentation
of Dohi (DSH, RAD; 127400), 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. For a discussion of genetic heterogeneity of reticulate pigment disorders,
see 179850.;
Inheritance : Autosomal dominant;
Molecular basis : Caused by mutation in the ADAM metallopeptidase domain 10 gene (ADAM10, 602192.0001);
Prefixed ID : #615537;
Origin ID : 615537;
UMLS CUI : C0406811;
Automatic exact mappings (from CISMeF team)
- Currated CISMeF NLP mapping
- DO Cross reference
- Genes related to phenotype
- HPO term(s)
- ORDO concept(s)
- Semantic type(s)
- UMLS correspondences (same concept)
- Validated automatic mappings to NTBT
