Decoding the Genetic Mysteries of Bardet-Biedl Syndrome: Diagnosis and Testing

Expert Reviewed By: ⁠Dr. Brandon Colby MD

Bardet-Biedl Syndrome (BBS) is a rare genetic disorder characterized by a wide range of symptoms, including obesity, retinal degeneration, polydactyly, and cognitive impairment. The complexity of this condition makes it essential to understand the genetic basis and the role of genetic testing in diagnosing and managing BBS. This article delves into the recent findings and advances in understanding, diagnosing, and using genetic testing for Bardet-Biedl Syndrome 2/6, digenic.

Understanding Bardet-Biedl Syndrome

Bardet-Biedl Syndrome is a ciliopathy, which means it affects the function of cilia, the hair-like structures found on the surface of cells. The dysfunction of cilia leads to the wide range of symptoms seen in BBS patients. The condition is inherited in an autosomal recessive manner, meaning that both parents must carry a mutation in the BBS gene for their child to be affected.

Genetic Variations in Bardet-Biedl Syndrome

Recent studies have identified various genetic variations associated with BBS. For instance, a study of 108 Indian BBS patients found a higher frequency of BBS10 and BBS1 gene variations, a novel gene (TSPOAP1), and a 36% frequency of digenic variants (source). Another case report highlighted the importance of genetic analysis for timely diagnosis by identifying a rare BBS12 gene mutation in a family with three members affected by BBS (source). Furthermore, two novel MKKS/BBS6 gene variants were identified in a Chinese BBS patient, suggesting a possible epistatic effect of a TMEM67 variant on BBS-associated loci (source).

Diagnosing Bardet-Biedl Syndrome

Diagnosing BBS can be challenging due to the wide range of symptoms and the genetic heterogeneity of the condition. A combination of clinical examination, family history, and genetic testing is typically used to confirm a diagnosis. In some cases, prenatal findings can provide early indications of BBS. For example, a case report documented a fetus with Bardet-Biedl syndrome presenting with ascites in the third trimester (source).

The Role of Genetic Testing in Bardet-Biedl Syndrome

Genetic testing plays a crucial role in diagnosing BBS and can be helpful in several ways:

• Confirming a diagnosis: Identifying the specific gene mutations involved in BBS can confirm a clinical diagnosis and provide valuable information for managing the condition.
• Prenatal diagnosis: Genetic testing can be performed on fetal cells obtained through amniocentesis or chorionic villus sampling to determine if the fetus has BBS.
• Preimplantation genetic diagnosis (PGD): Couples with a known risk of having a child with BBS can opt for PGD, a technique that involves testing embryos for the presence of BBS gene mutations before implantation during in-vitro fertilization (IVF).
• Carrier testing: Genetic testing can identify carriers of BBS gene mutations, providing valuable information for family planning and assessing the risk of having a child with BBS.

Conclusion

Understanding the genetic basis of Bardet-Biedl Syndrome is crucial for accurate diagnosis and effective management of the condition. Advances in genetic testing have made it possible to identify BBS gene mutations, enabling early intervention and better outcomes for patients. As research continues to uncover new genetic variations associated with BBS, the role of genetic testing in diagnosing and managing this complex condition will only become more critical.

About The Expert Reviewer

Dr. Brandon Colby MD is a US physician specializing in the personalized prevention of disease through the use of genomic technologies. He’s an expert in genetic testing, genetic analysis, and precision medicine. Dr. Colby is also the Founder of  and the author of ⁠⁠Outsmart Your Genes.

Dr. Colby holds an MD from the Mount Sinai School of Medicine, an MBA from Stanford University’s Graduate School of Business, and a degree in Genetics with Honors from the University of Michigan. He is an Affiliate Specialist of the American College of Medical Genetics and Genomics (⁠⁠ACMG), an Associate of the American College of Preventive Medicine (⁠⁠ACPM), and a member of the National Society of Genetic Counselors (⁠NSGC)