OMIA:000487-9796 : Hydrocephalus in Equus caballus (horse)

In other species: dog , domestic cat , tiger , puma , pig , llama , taurine cattle , sheep , rabbit , golden hamster , yellow-crowned parrot

Categories: Nervous system phene

Links to possible relevant human trait(s) and/or gene(s) in OMIM: 109400 (trait) , 112240 (trait) , 123155 (trait) , 209970 (trait) , 236600 (trait) , 236635 (trait) , 236640 (trait) , 236660 (trait) , 236670 (trait) , 236690 (trait) , 273730 (trait) , 276950 (trait) , 307000 (trait) , 307010 (trait) , 314390 (trait) , 123155 (trait) , 600257 (trait) , 600559 (trait) , 600991 (trait) , 615181 (trait)

Mendelian trait/disorder: yes

Mode of inheritance: Autosomal recessive

Considered a defect: yes

Key variant known: yes

Year key variant first reported: 2015

Cross-species summary: Enlargement of the cranium caused by accumulation of fluid.

Inheritance: Ducro et al. (2015) reported that "All 16 available cases and none of the controls were homozygous for the mutation, and all 17 obligate carriers (= dams of cases) were heterozygous."

Mapping: A genome-wide association study of hydrocephalus in 13 cases and 69 controls using 29,720 SNPs indicated the involvement of a region on ECA1" [from 61 to 87 Mb] (Ducro et. al, 2015). {Adapted by FN from text provided by Meredith O’Connell, working under the supervision of Professor Ernie Bailey; 24 April 2019}

Molecular basis: Ducro et al. (2015) reported that "Next generation DNA sequence analysis of 4 cases and 6 controls of gene exons within the [candidate] region [see Mapping section] revealed a [nonsense] mutation in β-1,3-N-acetylgalactosaminyltransferase 2 (B3GALNT2) as the likely cause of hydrocephalus in Friesian horses. The nonsense mutation XM_001491545 c.1423C>T corresponding to XP_001491595 p.Gln475* was identical to a B3GALNT2 mutation identified in a human case of muscular dystrophy-dystroglycanopathy with hydrocephalus.” {Adapted by FN from text provided by Meredith O’Connell, working under the supervision of Professor Ernie Bailey; 24 April 2019} Kolb and Klein (2019) reported the same likely causal variant in a congenital hydrocephalic Belgian draft horse.

Clinical features: “Hydrocephalus is defined as ‘an active distension of the ventricular system of the brain resulting from inadequate passage of cerebrospinal fluid (CSF) from its point of production within the cerebral ventricles to its point of absorption into the systemic circulation . . .’ Hydrocephalus can be acquired, e.g. due to infection or trauma, or can be hereditary in nature. To our best knowledge, no clear cases of a proven acquired hydrocephalus in horses have been reported in scientific literature. Different types of hydrocephalus have been identified based on the underlying mechanisms: communicating (increased production or impaired CSF absorption) or non-communicating (obstruction in CSF flow) . . . . Also, hydrocephalus can be internal or external, that is an accumulation of CSF respectively within or outside the ventricles of the brain. In horses, both external and internal hydrocephalus . . . have been diagnosed” (Ducro et. al, 2015). {Text provided by Meredith O’Connell, working under the supervision of Professor Ernie Bailey; 24 April 2019}

Prevalence: “Out of 60 stallions that were genotyped using a commercially available DNA test based on the B3GALNT2 mutation, 8 (13.3 %) were carrier of the allele T. Out of 805 broodmares, 139 (17.3 %) were also carrier.” (Ducro et al., 2015). As the authors reported, this gives a frequency of the likely causal variant of 8.5%. {Adapted by FN from text provided by Meredith O’Connell, working under the supervision of Professor Ernie Bailey; 24 April 2019}

Breeds: Belgian Draft (Horse) (VBO_0000915), Friesian (Horse) (VBO_0000969).
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).

Associated gene:

Symbol Description Species Chr Location OMIA gene details page Other Links
B3GALNT2 beta-1,3-N-acetylgalactosaminyltransferase 2 Equus caballus 1 NC_009144.3 (76839622..76890593) B3GALNT2 Homologene, Ensembl , NCBI gene


By default, variants are sorted chronologically by year of publication, to provide a historical perspective. Readers can re-sort on any column by clicking on the column header. Click it again to sort in a descending order. To create a multiple-field sort, hold down Shift while clicking on the second, third etc relevant column headers.

WARNING! Inclusion of a variant in this table does not automatically mean that it should be used for DNA testing. Anyone contemplating the use of any of these variants for DNA testing should examine critically the relevant evidence (especially in breeds other than the breed in which the variant was first described). If it is decided to proceed, the location and orientation of the variant sequence should be checked very carefully.

Since October 2021, OMIA includes a semiautomated lift-over pipeline to facilitate updates of genomic positions to a recent reference genome position. These changes to genomic positions are not always reflected in the ‘acknowledgements’ or ‘verbal description’ fields in this table.

OMIA Variant ID Breed(s) Variant Phenotype Gene Allele Type of Variant Source of Genetic Variant Reference Sequence Chr. g. or m. c. or n. p. Verbal Description EVA ID Year Published PubMed ID(s) Acknowledgements
348 Belgian Draft (Horse) Friesian (Horse) Hydrocephalus B3GALNT2 nonsense (stop-gain) Naturally occurring variant EquCab3.0 1 g.76887901C>T c.1423C>T p.(Q475*) XM_001491545; XP_001491595; Ducro et al. (2015): "The nomenclature for the mutation is c.1423C>T [GenBank:XM_001491545] corresponding to p.Gln475* [GenBank:XP_001491595]". As at 25 April 2019, Ensembl's Variant Effect Predictor (VEP) gives the EquCab3 c. and p. coordinates as having not changed from the EquCab2 coordinates reported by Ducro et al. (2015). The Ensembl ref is ENSECAT00000049072 rs3429464524 2015 26452345 c. and p. variant coordinates obtained from or confirmed by EBI's Some Effect Predictor (VEP) tool. EquCab3 g. coordinate provided by Meredith O’Connell, working under the supervision of Professor Ernie Bailey, 24 April 2019

Cite this entry

Nicholas, F. W., Tammen, I., & Sydney Informatics Hub. (2021). OMIA:000487-9796: Online Mendelian Inheritance in Animals (OMIA) [dataset].


Note: the references are listed in reverse chronological order (from the most recent year to the earliest year), and alphabetically by first author within a year.

2024 De Coster, T., Zhao, Y., Tšuiko, O., Demyda-Peyrás, S., Van Soom, A., Vermeesch, J.R., Smits, K. :
Genome-wide equine preimplantation genetic testing enabled by simultaneous haplotyping and copy number detection. Sci Rep 14:2003, 2024. Pubmed reference: 38263320. DOI: 10.1038/s41598-023-48103-7.
2019 Kolb, D.S., Klein, C. :
Congenital hydrocephalus in a Belgian draft horse associated with a nonsense mutation in B3GALNT2. Can Vet J 60:197-198, 2019. Pubmed reference: 30705458.
2017 Ayala-Valdovinos, M.A., Galindo-García, J., Sánchez-Chiprés, D., Duifhuis-Rivera, T. :
Genotyping of friesian horses to detect a hydrocephalus-associated c.1423C>T mutation in B3GALNT2 using PCR-RFLP and PCR-PIRA methods: Frequency in stallion horses in México. Mol Cell Probes 32:69-71, 2017. Pubmed reference: 28011345. DOI: 10.1016/j.mcp.2016.12.005.
2015 Ducro, B.J., Schurink, A., Bastiaansen, J.W., Boegheim, I.J., van Steenbeek, F.G., Vos-Loohuis, M., Nijman, I.J., Monroe, G.R., Hellinga, I., Dibbits, B.W., Back, W., Leegwater, P.A. :
A nonsense mutation in B3GALNT2 is concordant with hydrocephalus in Friesian horses. BMC Genomics 16:761, 2015. Pubmed reference: 26452345. DOI: 10.1186/s12864-015-1936-z.
2013 Sipma, K.D., Cornillie, P., Saulez, M.N., Stout, T.A., Voorhout, G., Back, W. :
Phenotypic characteristics of hydrocephalus in stillborn Friesian foals. Vet Pathol 50:1037-42, 2013. Pubmed reference: 23676552. DOI: 10.1177/0300985813488955.
2011 Oey, L., Müller, J.M., von Klopmann, T., Jacobsen, B., Beineke, A., Feige, K. :
Diagnosis of internal and external hydrocephalus in a warmblood foal using magnetic resonance imaging. Tierarztl Prax Ausg G Grosstiere Nutztiere 39:41-5, 2011. Pubmed reference: 22138744.
2002 Jaworski, Z., Kasperowicz, B., Wroblewski, Z. :
A case of hydrocephalus in a Polish Primitive Horse Medycyna Weterynaryjna 58:230-231, 2002.
1996 Rivas, L.J., Hinchcliff, K.W., Robertson, J.T. :
Cervical meningomyelocele associated with spina bifida in a hydrocephalic miniature colt Journal of the American Veterinary Medical Association 209:950 ff., 1996.
1993 Johnson, P.J., Lin, T.L., Jennings, D.P. :
Diffuse Cerebral Encephalopathy Associated with Hydrocephalus and Cholesterinic Granulomas in a Horse Journal of the American Veterinary Medical Association 203:694-697, 1993. Pubmed reference: 8407539.
1992 Ojala, M., Ala-Huikku, J. :
Inheritance of hydrocephalus in horses. Equine Vet J 24:140-3, 1992. Pubmed reference: 1582393.
1980 Bowman, R.W. :
Congenital hydrocephalus in 2 foals. Mod Vet Pract 61:862-4, 1980. Pubmed reference: 7421786.
1979 Carbery, J.T. :
A case of equine hydrocephalus. N Z Vet J 27:158, 1979. Pubmed reference: 291822. DOI: 10.1080/00480169.1979.34633.
1976 Bester, R.C., Cimprich, R.E., Evans, L.H. :
Hydrocephalus in an 18-month-old colt. J Am Vet Med Assoc 168:1041-2, 1976. Pubmed reference: 931772.
1950 Petiot, M.P. :
[Hydrocephalus of the colt]. Rec Med Vet Ec Alfort 126:467-70, 1950. Pubmed reference: 14781419.

Edit History

  • Created by Frank Nicholas on 06 Sep 2005
  • Changed by Frank Nicholas on 14 Dec 2011
  • Changed by Frank Nicholas on 30 Dec 2015
  • Changed by Frank Nicholas on 12 Feb 2019
  • Changed by Frank Nicholas on 25 Apr 2019
  • Changed by Frank Nicholas on 26 Apr 2019
  • Changed by Imke Tammen2 on 17 Aug 2021