• Arabian;
  • coat colour dilution lethal;
  • dilute lethal;
  • horse;
  • lavender foal syndrome;
  • MYO5A;
  • myosin-Va;
  • neurological;
  • single-base deletion


Lavender Foal Syndrome (LFS) is a rare autosomal recessive lethal disorder affecting Arabian foals which is also characterized by a dilute coat colour and severe neurological signs. Dilute mouse and rat mutants, and Griscelli syndrome type 1 in humans, which are characterized by similar clinical signs, are caused by mutations in the MYO5A gene. MYO5A was, therefore, identified as a possible candidate gene for LFS. Sequencing of the coding region identified a single-base deletion in a conserved region of the tail domain. The deletion produces a truncated protein product through the insertion of a premature stop codon (p.Arg1487AlafsX13). The deletion was confirmed as the causative mutation by genotyping affected, carrier and normal individuals.