In other species: rock pigeon , chicken , turkey , western gray kangaroo , dog , domestic cat , domestic horse , pig , Arabian camel , guanaco , llama , Western roe deer , goat , sheep , domestic guinea pig , alpaca , springbok

Categories: Skeleton phene (incl. short stature & teeth) , Limbs / fins / digit / tail phene

Links to possible relevant human trait(s) and/or gene(s) in OMIM: 174500 (trait) , 605522 (gene) , 188740 (trait)

Single-gene trait/disorder: unknown

Disease-related: yes

Cross-species summary: Often called preaxial polydactyly (PPD)

Inheritance: As summarised by Johnson et al. (1981), there was no consensus on the mode of inheritance of polydactyly in cattle in previously published reports. In an attempt to clarify the situation, these authors conducted a series of breeding trials in Simmental cattle. Their data excluded all models of single-locus inheritance, leaving multifactorial inheritance as the only remaining possibility in this breed. (With thanks to Dave Steffen)

Molecular basis: Jacinto et al. (2025) investigated a crossbred animal with polydactyly. Whole genome seequencing analysis did not identify likely causal variants: "Analysis of the depth of coverage along all chromosomes revealed a partial monosomy of chromosome 28 at ~ 2.7 Mb from the chromosome end ... . ... The haploinsufficient region contains 39 annotated genes ... and hemizygosity for these genes may explain the observed phenotype."

Breeds: Holstein Friesian (Cattle) (VBO_0000239), Mashona, Zimbabwe (Cattle) (VBO_0003606), Simmental (Cattle) (VBO_0000380), Swedish Red and White (Cattle) (VBO_0000392).
Breeds in which the phene or likely causal variants have been documented. If a likely causal variant has been documented, see variant-specific breed information in the variant table. (Breed information may be incomplete).