How is Bardet-Biedl Syndrome Inherited?
Explaining the Genetics of BBS
Bardet-Biedl Syndrome (BBS) is a genetic disorder, meaning it is caused by changes in a person’s DNA. Understanding how BBS is inherited can help families make informed decisions, recognize potential risks, and consider genetic counseling.
Autosomal Recessive Inheritance
BBS follows a pattern called autosomal recessive inheritance. This means:
- A person must inherit two copies of the faulty gene—one from each parent—to develop the condition.
- Parents who carry only one copy of the faulty gene typically show no symptoms. These individuals are known as carriers.
When both parents are carriers:
- There is a 25% chance the child will inherit BBS (two faulty copies).
- There is a 50% chance the child will be a carrier (one faulty copy).
- There is a 25% chance the child will inherit two working copies of the gene and not be a carrier or have the disease.
Many Genes Can Be Involved
BBS is genetically complex. Researchers have identified over 20 different genes that can cause BBS when mutated. These genes are involved in how cells communicate and how certain parts of cells—like cilia—function.
Because multiple genes are linked to BBS, genetic testing often includes a panel of known BBS-related genes.
Carrier Testing and Family Planning
If you or a family member has BBS, genetic counseling is highly recommended. A counselor can:
- Explain inheritance patterns in simple terms
- Help identify carrier status in other family members
- Discuss reproductive options, such as IVF with genetic screening
Carrier testing can be especially helpful for:
- Relatives of someone diagnosed with BBS
- Couples planning to start a family
- People from communities with a higher incidence of BBS
What If There’s No Family History?
Because BBS is rare and inherited recessively, many families have no idea they’re carriers until a child is diagnosed. That’s why access to genetic testing and early diagnosis is so important.
Up Next: Diagnosing Bardet-Biedl Syndrome
In our next article, we’ll explore how BBS is diagnosed—what signs doctors look for, the role of genetic testing, and why early detection matters so much for long-term health and quality of life.