Dr. van Haeringen Laboratorium B.V.

P314 Occipitoatlantoaxial Malformation (OAAM)


Homeobox genes direct the formation of many body structures during early embryonic development. HOXD3 is involved in the formation of the occiput, axis and atlas and HOXD4 in the formation of cervical vertebrae 1-3. Developmental defects lead to occipitoatlantoaxial malformations (OAAM), a disease presenting with a range of differing phenotypes. Equine OAAM has been classified into six groups and was described as an autosomal recessive trait in Arabian horses. In an Arabian horse family, a mutation in the HOXD3/4 region was identified, which appeared to be causal for OAAM in the affected foal. Hence, other Arabian foals diagnosed with OAAM did not have the mutation. Additional, yet unknown mutations may exist across the HOXD locus in Arabian foals affected with OAAM.

Test specific information



Symptoms will develop at a young age. Within a few hours to a maximum of several weeks after birth, the characteristics that go with these genetic effects will become visible.

Turn Around Time

The turn-around-time of a test depends to a large extent on the logistics of sample transportation to the laboratory. After receiving the sample at the test location, you can normally expect the result within 10 working days. A longer delivery time applies to tests carried out by a Partner Lab.

Location of disease or trait

This disease is present in the entire body, but causes main effects in the internal organs such as stomach, intestinal tract, liver and / or kidneys. In a number of cases, the disease affects one major internal organ.

Breed dependence

This DNA test is available for the following breeds: Arabians. Additional information is available in the Frequently Asked Questions (FAQ).

Sample type

For this DNA test we accept the following materials: Blood EDTA, Blood Heparin, Hair, Semen, Tissue. Please contact Dr. Van Haeringen Laboratorium if you wish to submit other material as listed.


An animal can be free and has in that situation two healthy alleles. When used in breeding this animal will not become ill due to the disease. It cannot spread the disease in the population.

An animal can be carrier and has in that situation one healthy and one disease allele. When used in breeding 50 percent of the offspring will receive the disease allele. Carriers will not become ill.

An animal can be affected and has in that situation two disease alleles. When used in breeding all offspring will also receive the disease allele. Affected will become ill.


This genetic factor is inherited in an autosomal, recessive, mode. This means, that the individual can be free of the disease (homozygote normal), affected (homozygous affected) or carrier (heterozygous).

Carriers may spread the mutation in a population without showing symptoms themselves. Because of this, it is extremely important to identify carriers correctly to prevent spreading of a mutation.

Severity of Disease


Code P314

Occipitoatlantoaxial Malformation (OAAM)

€ 47,80 (Incl. 21% VAT)
€ 39,50 (Excl. VAT)