Autosomal dominant polycystic kidney disease
How is autosomal dominant polycystic kidney disease inherited?
Autosomal dominant polycystic kidney disease (ADPKD) is inherited in an autosomal dominant manner. This is one way a disorder or trait can be passed down through a family. The first word, "autosomal," means on a chromosome that both males and females carry. Therefore, the disorder can affect either gender. The second word, "dominant," means a change in one copy of the altered gene that causes the disorder is enough for them to develop ADPKD. Two genes that, when altered or mutated, are known to cause this disorder. They are the PKD1 or the PKD2 genes. Everyone has two copies of every gene - one inherited from our mother and one from our father - for a dominant condition, only one of them needs to have the problem. This means that if a parent carries an altered PKD1 or PKD2 gene, they have a 50% chance to pass the affected gene to each of their offspring, regardless of gender. This also means that there is a 50% chance that an affected parent would not pass this on to their children. Genetic testing may be available to determine if a child has inherited the altered gene. Genetic testing of adolescents under the age of 18 for ADPKD, a serious disorder without a specific treatment, is controversial and many doctors do not recommend it.
In about 5%-10% of people, there is no previous history of ADPKD in the family. The altered gene occurs randomly, most likely after fertilization. This is also called a de novo mutation. The altered gene in the child can be passed on as an autosomal dominant trait. In families with a child with a de novo mutation, the likelihood of having another child with ADPKD is extremely low.
If you have a family member with ADPKD and you would like to know if you are a carrier, talk to your doctor or meet with a genetic counselor to discuss testing options.Genetic counselors in the United States can be found on the National Society of Genetic Counselors website. Genetic counselors in Canada can be found at the Canadian Association of Genetic Counselors website.
Autosomal Dominant Polycystic Kidney Disease. The National Organization for Rare Diseases website. Accessed Jan 20, 2016. https://rarediseases.org/rare-diseases/autosomal-dominant-polycystic-kidney-disease
Polycystic Kidney Disease. Genetics Home Reference website. Accessed Jan 20, 2017. https://ghr.nlm.nih.gov/condition/polycystic-kidney-disease#