In other species: dog , domestic cat , ass (donkey) , taurine cattle , goat , water buffalo

Categories: Pigmentation phene

Links to possible relevant human trait(s) and/or gene(s) in OMIM: 172800 (trait) , 164920 (gene)

Mendelian trait/disorder: yes

Disease-related: no

Key variant known: yes

Year key variant first reported: 2017

Cross-species summary: Variable degree of white spotting ranging from tiny white spots up to completely white animals. The absence of pigment is caused by the absence of skin melanocytes ("leucism, leucistic"), not by failure in the biochemical reactions required for pigment synthesis.

Molecular basis: Whole-genome sequencing of "One spotted and eight solid camels" enabled Holl et al. (2017) to report that the "spotted camel was heterozygous for a frameshift deletion in KIT (c.1842delG, named KITW1 for White spotting 1), whereas all other camels were wild-type (KIT+/KIT+). . . . The frameshift results in a premature stop codon five amino acids downstream, thus terminating KIT at the tyrosine kinase domain. . . . p.M614IfsX5" These authors also reported that "No additional mutations unique to the spotted camel were detected in the EDNRB, EDN3, SOX10, KITLG, PDGFRA, MITF, and PAX3 candidate white spotting genes". They also reported that a different type of white spotting is likely to be due to another variant.

Clinical features: Holl et al. (2017): "The US spotted camels were visibly smaller in overall body size than the solid camels, though no quantitative measures were assessed. Two of the owners mentioned that spotted camels are known for being roughly 30 cm shorter at maturity."

Associated gene: