What are the symptoms?

Dr. Philip Beales, a doctor and researcher based in the UK, compiled a set of primary (or more common) and secondary symptoms associated with BBS. 

These symptoms are used to diagnose BBS in an individual before genetic testing has been completed or if the genetic testing does not reveal a mutation in a gene known to cause BBS. According to Dr. Beales’ diagnostic criteria, a person should be diagnosed with BBS if they have four of the primary characteristics (see below) or if the person had three primary characteristics and at least two secondary characteristics. Note that most people with BBS do not have all of the characteristics listed below. 

The primary characteristics are: 

• Visual impairment caused by retinal abnormalities 

• Obesity, typically apparent by age one 

• Polydactyly (extra fingers or toes) 

• Hypogonadism 

• Renal anomalies (kidney malformations and/or malfunctions) 

• Learning disabilities 

Secondary characteristics include: 

• Developmental delays 

• Behavioral problems 

• Neurological problems 

• Hypertension (high blood pressure) 

• Speech disorders 

• Dental anomalies (small teeth, small lower jaw, short teeth) 

• Lack of a sense of smell (anosmia) 

• Flat, wide feet; no arches 

• Thyroid problems 

• Strabismus (“lazy eye” -- one eye focuses and the other wanders) 

• Short stature relative to parents’ height 

• Toe and finger variations: short (brachydactyly); curved (clinodactyly), especially the outer fingers or toes; mild webbing (syndactyly) especially between the 2nd and 3rd toes 

As genetic testing for BBS has improved it is becoming clearer that the symptoms and severity of symptoms are even more diverse than originally thought. 

For example, while some people with BBS lose most of their vision by their mid-teens, others have maintained enough vision to drive into their 30s. While some people with BBS have significant learning disabilities and cognitive impairment, others do not and have IQ scores well above normal. 

A diagnosis of BBS does not necessarily indicate any particular symptom or severity of symptoms.

How many people have BBS?

BBS is officially a “rare disease” affecting approximately 1 in 250,000 people around the world. Based on general population trends, there are likely about 3000 people in the United States and Canada living with BBS. BBS is more common in some areas of the world including Newfoundland (Canada) and in the Middle East (among Bedouin populations)

Is there a cure for BBS?

There is currently no cure for BBS, but that does not mean that there is nothing that can be done to help people with BBS. 

Children with BBS benefit greatly from therapies like physical therapy, occupational therapy, speech therapy and vision services. Everyone with BBS benefits from exercise and careful attention to diet to limit weight gain. 

Research is ongoing into understanding the basic mechanisms at the cellular level that ultimately cause BBS. This research will provide clues to develop future treatments. 

Treatment research general falls into three categories: 

Stem Cell Therapy: Delivering new cells without the defective BBS gene that can multiply and replace defective cells within the body. 

Gene Therapy: rather than replacing cells, replacing the defective gene inside of existing cells. 

Suppressor Therapy: rather than changing DNA with new cells or in existing cells, overcoming the limitations of those cells by boosting their function through the inactivation of other genes or cellular pathways.