In other species: chicken , tammar wallaby , dog , domestic cat , taurine cattle , sheep , Swainson's hawk

Categories: Limbs / fins / digit / tail phene

Links to possible relevant human trait(s) and/or gene(s) in OMIM: 212780 (trait) , 186100 (trait) , 186200 (trait) , 186300 (trait) , 604270 (gene)

Mendelian trait/disorder: yes

Disease-related: no

Key variant known: no

Cross-species summary: Fusion of the claws (cleats or digits). Occurs in one, two, three or (rarely) four legs.

Species-specific description: Facioli et al. (2021): "The swine mulefoot (SM) is a rare condition characterized by a non-cloven hoof due to the partial or total fusion of the phalanges. ... The swine mulefoot is a well-adapted animal to be raised in outdoor systems ... . In addition to that, animals with this characteristic tend to have higher lard content in their carcass. Currently, the mulefoot phenotype is an undesirable trait for industrial-scale swine production as this prioritizes intensive breeding systems with animal confinement on cement floors, and now those animals are at risk of extinction ..."

Inheritance: Facioli et al. (2021) "An experimental population was produced using a half-sib mating where the [Piau crossbred] male had the mulefoot phenotype and the females (n = 6) had cloven hoofs. The cross resulted in 27 (47%) animals with the mulefoot characteristic and 30 (53%) normal animals, indicating the possible dominant gene action."

Mapping: Facioli et al. (2021) "aimed to characterize the association between SNP and the mulefoot phenotype using a Genome-Wide Association Study (GWAS). ... . Animals were further genotyped using the Illumina PorcineSNP50k BeadChip, and SNPs were tested for associations. Twenty-nine SNPs located on the SSC15, SSC4, and SSCX were associated with the mulefoot phenotype (p-value <5 × 10-5). Six markers were found in the intronic regions of VWC2L, CATIP, PDK3, PCYT1B, and POLA1 genes. The marker rs81277626, on SSC15:116,886,110 bp, is located in the Von Willebrand Factor C Domain (VWC2L), a possible functional candidate gene. The VWC2L is part of a biological process involved with the bone morphogenetic protein (BMP) signaling pathway, previously associated with syndactyly in other species."

Breeds: Casco de Mula, Colombia (Pig) (VBO_0012556), Mulefoot, United States of America (Pig) (VBO_0013230), Piau, Brazil (Pig) (VBO_0012726).
Breeds in which the phene has been documented. (If a likely causal variant has been documented for the phene, see the variant table breeds in which the variant has been reported).