Mucopolysaccharidosis I (Plott Hound Type)
Affected Genes: IDUA
Inheritance: Autosomal Recessive
Variant(canFam6):
chr3:94000935: C>T
Breed: Plott
General Information: Mucopolysaccharidosis I (MPS I) in Plott Hounds results from a deficiency in the enzyme alpha-L-iduronidase, essential for degrading glycosaminoglycans (GAGs) in the body. The inability to break down GAGs leads to their accumulation, affecting multiple organ systems including bones, joints, heart, eyes, and nervous system. Dogs with MPS1 display a range of symptoms starting between 4 to 6 months, including joint laxity, skeletal deformities, growth delays, and pain when handled. Additional signs may include vision cloudiness, arched backs, stiff gait, umbilical hernias, and a distinct facial appearance. Most affected dogs face a life expectancy of only 2-3 years due to disease complications.
How to Read Your Dog's Test Results for this Genetic Variant:
Two Variants Detected: Dog Likely Affected
One Variant Detected: Dog Unlikely Affected
No Variants Detected: No Effect
Gene / Testing Information: The IDUA gene test identifies carriers of the gene mutation responsible for Mucopolysaccharidosis I (MPS I) in Plott Hounds. This disorder is inherited in an autosomal recessive pattern, meaning two copies of the mutated gene, one from each parent, are required for a dog to exhibit clinical signs of the disease. Dogs that are carriers (having one copy of the mutated gene) do not typically show symptoms but can produce affected offspring if bred with another carrier. A mating between two carriers has a 25% chance of producing affected offspring and a 50% chance of producing carriers. Preventing the spread of this debilitating condition is crucial, thus breeding known carriers is strongly discouraged. Ensuring that dogs used in breeding programs are tested and cleared of this mutation helps maintain the health of future generations and prevents the birth of affected puppies.
References:
Dierenfeld AD, McEntee MF, Vogler CA, Vite CH, Chen AH, Passage M, Le S, Shah S, Jens JK, Snella EM, Kline KL, Parkes JD, Ware WA, Moran LE, Fales-Williams AJ, Wengert JA, Whitley RD, Betts DM, Boal AM, Riedesel EA, Gross W, Ellinwood NM, Dickson PI. Replacing the enzyme alpha-L-iduronidase at birth ameliorates symptoms in the brain and periphery of dogs with mucopolysaccharidosis type I. Sci Transl Med. 2010 2(60):60ra89.
Menon KP, Tieu PT, Neufeld EF. Architecture of the canine IDUA gene and mutation underlying canine mucopolysaccharidosis I. Genomics 1992 14(3):763-768.
Shull RM, Helman RG, Spellacy E, Constantopoulos G, Munger RJ, Neufeld EF. Morphologic and biochemical studies of canine mucopolysaccharidosis I. Am J Pathol. 1984 114(3):487-495.
Shull RM, Munger RJ, Spellacy E, Hall CW, Constantopoulos G, Neufeld EF. Canine alpha-L-iduronidase deficiency. A model of mucopolysaccharidosis I. Am J Pathol. 1982 109(2):244-248.
Spellacy E, Shull RM, Constantopoulos G, Neufeld EF. A canine model of human alpha-L-iduronidase deficiency. Proc Natl Acad Sci USA. 1983 80(19):6091-6095.