Other name: Alport syndrome
Affected Gene: COL4A5
Inheritance: X-Linked Recessive
In hereditary genetic diseases linked to the X chromosome, the following rules apply:
-For a recessive disease, the male is affected (at risk of developing the disease) even if he has only one copy of the mutation.
There is no such thing as male-to-male transmission, because a male never passes on his X chromosome to his sons.
-All females of an affected male will inherit the mutant gene.
-Females that are carriers have a 50% chance of passing the mutant gene to their sons and daughters.

Mutation: CanFam3.1 X g.82196868G>T c.3079G>T
OMIA link: 001112-9615

Appropriate breeds for testing: Samoyed

Symptoms:  Hereditary nephritis is a kidney disease. Normally, there is no protein in the urine, but in affected dogs, a defect allows blood proteins to be filtered by the kidneys and lost in the urine. These urinary proteins can be detected in the urine as early as 2 and 3 months of age and signs of chronic renal failure (thirst, frequent urination, vomiting, inappetence, etc.) can appear between 7-15 months. Since this disease is linked to the X chromosome, male dogs are more often affected than females. Females with this mutation may also show signs of kidney disease, but the progression is usually slower. Some females do not show any signs of kidney disease. Affected male dogs eventually die of chronic kidney disease at 15 months of age.

References:
Baumal R, Thorner P, Valli VEO, McInnes R, Marrano P, Jacobs R, Binnington A, Bloedow AG. Renal disease in carrier female dogs with x-linked hereditary nephritis. Am J Pathol. 1991 Oct;139(4):751-64.
Jansen B, Valli VE, Thorner P, Baumal R, Lumsden JH. Samoyed glomerulopathy: serial, clinical and laboratory (urine, serum biochemistry and hematology) studies. Can J Vet Res. 1987 Jul;51(3):387-93.
Zheng K, Thorner PS, Marrano P, Baumal R, McInnes RR. Canine X chromosome-linked hereditary nephritis: A genetic model for human X-linked hereditary nephritis resulting from a single base mutation in the gene encoding the alpha-5 chain of collagen type IV. Proc Natl Acad Sci USA. 1994 Apr 26;91(9):3989-9.