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Frame overo/lethal white syndrome (OLWS)

Summary

Frame overo markings include eye-catching white patches, and often a white face accompanied by one or two blue eyes. The amount of white on a frame overo horse or pony can be highly variable, from a couple of white hairs all the way up to majority white coat colours.

Frame overo is unique among white coat colour patterns in that foals born with two copies of the frame overo gene suffer from the heart-breaking and fatal Overo Lethal White Syndrome (OLWS). Testing helps breeders avoid crosses that could produce Lethal White Syndrome foals.

Gene or region and technical reference

Gene: EDNRB (causative). Reference: Yang et al. (1998)
Metallinos, Bowling and Rine. (1998)

Reported alleles

n. Test developed using animal controls.

Ovr. Test developed using animal cases.

Panels: groups of tests that are often ordered together

This test is in the full colour panel.

This test is in the Miniature health & colour panel.

This test is in the patterns panel.

This test is in the QH health panel.

This test is in the QH health & colour panel.


horse

Frame overo horses often have distinctive white markings. They can also have one or more partially or completely blue eyes.

Order tests

There is a one-off sample processing fee of $40 per animal plus the cost of your tests.

How many animals are you testing? Discount or society code:


Pedigree

$33 A DNA profile ... more


Panels


Colour panels

$40 Dilutions panel ... more

$120 Full colour panel ... more

$70 Patterns panel ... more


Panels by breed

$100 Arabian health & colour ... more

$50 Arabian health panel ... more

$66 Fjord horse panel ... more

$40 Friesian health & colour ... more

$120 Gypsy health & colour ... more

$50 Miniature ACAN panel ... more

$250 Miniature health & colour ... more

$160 QH health & colour ... more

$90 QH health panel ... more


Good moves


Gaited horses

$9 Lateral gait marker ... more


Good looks


Coat colour

$9 Agouti (bay factor) (agouti) ... more

$9 Red/black ... more


Coat pattern

$9 Frame overo/lethal white syndrome (OLWS)

$9 Grey/melanoma ... more

$9 Lp/Appaloosa/night blindness (Lp) ... more

$9 PATN1 coat pattern modifier (PATN1) ... more

$9 Roan marker ... more

$9 Sabino 1 ... more

$9 Splashed white 1/deafness (SW1) ... more

$9 Splashed white 2/deafness (SW2) ... more

$9 Splashed white 3/deafness (SW3) ... more

$9 Splashed white 5/deafness (SW5) ... more

$9 Tobiano ... more

$9 W13 dominant white (W13) ... more

$9 W20 white markings (W20) ... more

$9 W22 dominant white (W22) ... more

$9 W25 dominant white (W25) ... more

$9 W26 dominant white (W26) ... more

$9 W27 dominant white (W27) ... more


Pure- and part-bred Akhal-Tekes

$14 Naked foal syndrome (NFS) ... more


Pure- and part-bred Connemaras

$14 Hoof wall separation disease (HWSD) ... more


Good looks


Colour dilution

$9 Champagne ... more

$9 Cream ... more

$9 Dun and nd1 (dun/nd1) ... more

$9 Pearl ... more

$9 Taffy/silver/eye abnormalities (silver) ... more


Good health


Multiple breeds

$14 Cerebellar abiotrophy (CA) ... more

$14 Foal immunodeficiency syndrome (FIS) ... more

$14 Fragile foal syndrome (FFS) ... more

$9 Frame overo/lethal white syndrome (OLWS)

$9 Grey/melanoma ... more

$9 Lp/Appaloosa/night blindness (Lp) ... more

$14 Ocular squamous cell carcinoma (SCC) ... more

$14 Polysaccharide storage myopathy 1 (PSSM1) ... more

$9 Splashed white 1/deafness (SW1) ... more

$9 Taffy/silver/eye abnormalities (silver) ... more


Pure- and part-bred Arabians

$14 Cerebellar abiotrophy (CA) ... more

$14 Lavender foal syndrome (LFS) ... more

$14 Occipitoatlantoaxial malformation (OAAM) ... more

$14 Severe combined immune deficiency (SCID) ... more


Pure- and part-bred Friesians

$14 Friesian dwarfism ... more

$14 Hydrocephalus ... more


Pure- and part-bred Miniature horses

$14 D1 form of Miniature dwarfism (D1) ... more

$14 D2 form of Miniature dwarfism (D2) ... more

$14 D3* form of Miniature dwarfism (D3*) ... more

$14 D4 form of Miniature dwarfism (D4) ... more

$140 Skeletal atavism (SA) ... more


Pure- and part-bred QH and/or Paint

$14 Glycogen branching enzyme deficiency (GBED) ... more

$14 Hereditary equine regional dermal asthenia (HERDA) ... more

$14 Hyperkalaemic periodic paralysis (HYPP) ... more

$14 Immune mediated myositis/myosin heavy-chain myopathy (IMM/MYHM) ... more

$14 Malignant hyperthermia (MH) ... more

$14 Polysaccharide storage myopathy 1 (PSSM1) ... more

$9 Splashed white 2/deafness (SW2) ... more

$9 Splashed white 3/deafness (SW3) ... more

$9 Splashed white 5/deafness (SW5) ... more


Pure- and part-bred Saddlebreds

$14 Junctional epidermolysis bullosa (JEB2) ... more

Tests can be in the list more than once when the gene in question has more than one effect. It is OK to select the same test once or more than once, the price is the same.