What are the main Arabian genetic diseases ? And genetic tests available ?
■ Cerebellar abiotrophy : Autosomal recessive
■ Lavender foal syndrome, aka Coat color dilution lethal, found primarily in horses with Egyptian bloodlines; characteristic signs of LFS include seizures, severe hyperextension of limbs, neck, and back (opisthotonos). Autosomal recessive.
■ Severe combined immunodeficiency (SCID), Autosomal recessive; characterized by an underdeveloped immune system that results in foals with elevated temperatures, respiratory stress, and diarrhea.
■ Occipitoatlantoaxial malformation (OAAM), an inherited developmental condition primarily found in Arabian horses, causes abnormal development of the vertebrae and results in compression of the upper cervical cord with subsequent neurological damage. Autosomal recessive.
What are the main Friesian genetic diseases ? And genetic tests available ?
■ Distichiasis : Distichiasis is a condition in which the eyelashes grow from an abnormal position on the edges of the eyelids. These misplaced lashes can contact the cornea, leading to irritation and corneal ulcers, which can impact vision.
■ Friesian Horse Dwarfism : Dwarfism in Friesians is an inherited disorder characterized by a disproportionate growth with reduced bone length of limbs and ribs while the size of the head and length of the back are normal.
■ Friesian Horse Hydrocephalus : Hydrocephalus is an inherited condition in Friesian and Friesian crosses characterized by excessive accumulation of fluid in the brain that results in severe cranial distension.
What are the main QH genetic diseases ? And genetic tests available ?
■ Glycogen Branching Enzyme Deficiency (GBED) : fatal genetic disorder that results from the inability to correctly store glycogen in several organs of the body.
■ Hereditary Equine Regional Dermal Asthenia (HERDA) : an inherited skin condition primarily found in Quarter Horses that is characterized by hyperextensible skin, scarring, and severe lesions along the back of affected horses.
■ Hyperkalemic Periodic Paralysis (HYPP) : inherited disease of the muscles primarily found in Quarter Horses which is characterized by sporadic episodes of muscle tremors or paralysis.
■ Myosin-Heavy Chain Myopathy (MYHM) : Formerly known as IMM, MYHM is a muscle disease in Quarter Horses and related breeds that results in two distinct clinical disease presentations, immune-mediated myositis (IMM) and non-exertional rhabdomyolysis. Both presentations involve muscle loss or damage and are linked to the same genetic variant.
■ Malignant Hyperthermia (MH) : inherited disease in which affected horses can be triggered by halogenated anesthetics, succinylcholine, stress, or excitement, which can induce a hyper-metabolic state characterized by symptoms including muscle contracture, elevated temperature, and an irregular heart rhythm.
■ Polysaccharide Storage Myopathy (PSSM1) : Type 1 Polysaccharide Storage Myopathy is a glycogen storage disease that results in the accumulation of abnormal complex sugars in muscle cells, which can lead to muscle pain, weakness, and reluctance to move.
