Dwarfism with skeletal dysplasia associated with a variant in B4GALT7 (β-1,4-galactosyltransferase 7, involved in proteoglycan linker synthesis). It forms part of the Friesian FH8 haplotype, with juvenile mortality and abnormal height in homozygosity. Autosomal recessive inheritance. The test is complementary to the clinical and radiographic examination.

Frisón. Frequencies: limited data.

- Reduced height and disproportionate dwarfism
- Skeletal and joint dysplasia
- Juvenile mortality in homozygosity
- Growth retardation

The dossier records the B4GALT7 gene and the variant NC_009157.3:g.3772591C>T (XM_023617086.1:c.50G>A; p.Arg17Lys; rs3447120064), integrated into the FH8 haplotype. No author or year is stated.

- Genotype breeding animals for the FH8 haplotype (carrier vs. clear)
- Avoid carrier × carrier matings
- Use the FH haplotype panel in matings
- Do not use carriers as heavy-use sires

Differential diagnosis with ACAN dwarfism, skeletal atavism and other dysplasias. Complementary: radiographic study and monitoring of neonatal mortality.

1. OMIA:002068 y OMIA:003063 (haplotipos FH del Frisón)
2. Steensma et al., estudio de haplotipos FH en el Frisón (PMID 41808016)