Also in Friesian horses, 13.3–17.3% are carrying a mutation of the beta-1,3-N-acetylgalactosaminyltransferase 2 (B3GALNT2) gene, responsible for the autosomal recessive congenital hydrocephalus (CH), which results in stillbirth, dystocia or postnatal euthanasia54. Here, B3GALNT2 is linked to congenital hydrocephalus.