Complex vertebral malformation / CVM / HHC (SLC35A3-related) - Cattle

CVM in Holstein-Friesian cattle

This DNA test examines the classic SLC35A3 variant c.559G>T for complex vertebral malformation. The disorder is also known as CVM, complex vertebral malformation or Haplotype HHC. CVM is a severe inherited skeletal development disorder in Holstein-Friesian cattle.

What does CVM cause?

• Skeletal defects: affected calves have malformations of vertebrae, ribs and limbs.
• Pregnancy loss: many homozygous embryos die during gestation or are stillborn.
• Severe calf abnormalities: liveborn or stillborn calves may show a short neck, twisted limbs and obvious malformations.

Practical value of this test

The result helps breeders distinguish clear animals, carriers and genetically affected animals. Because carriers appear healthy, DNA testing is important to avoid risk pairings and manage CVM in Holstein-Friesian breeding lines.