What Your Test Results Mean:

Carriers typically show no symptoms of Alport syndrome; however, carriers are at an increased risk of having a child with Alport syndrome. Risk for the current or future pregnancies is dependent on your partner’s carrier status. Carrier testing of your partner is recommended in addition to consultation with a genetic counselor.

Disease Explained:

Autosomal recessive Alport syndrome is an inherited disorder caused by abnormal type IV collagen production. It is characterized by kidney disease, sensorineural hearing loss, and sometimes eye abnormalities. Blood in the urine (hematuria) and high levels of protein in the urine are typically the first signs of the disorder followed by hearing loss. Kidney failure may occur in the teenage years, but may not develop until as late as 40-50 years of age. Kidney dialysis or transplantation is available for those with end-stage renal disease.

How the Genetics Works:

COL4A4–associated Alport syndrome is an autosomal recessive disorder caused by pathogenic variants in the COL4A4 gene. All individuals have two copies of COL4A4. Carriers of COL4A4-associated Alport syndrome have a variant in one copy COL4A4 while individuals with the disorder have variants in both copies the COL4A4 gene, one inherited from each parent. Risk for two carriers to have a child with the disorder is 25%.