Bardet-Biedl Syndrome (BBS) is a rare, complicated genetic disease. BBS affects 1 in 250,000 people worldwide. It is diagnosed in early childhood. Morbid obesity is one of the main symptoms of BBS. What are the causes of Bardet-Biedl syndrome and how is it treated?

"Syndrome" is a group of congenital symptoms and defects that accompany a specific genetic condition.BBSis most often characterized byobesity , retinal degeneration, polydactyly, intellectual retardation and kidney failure.

Name:Bardet-Biedl Syndrome(BBS, Bardet-Biedl Syndrome) comes from two of its discoverers. The first was the French physician Georges Louis Bardet, and the second was the Hungarian pathologist and endocrinologist Arthur Biedl. The first case of BBS was described in the 1920s.

Bardet-Biedl syndrome: causes

Based on tests performed on approx. 75% of of people with BBS, there are currently 21 known genes that cause this syndrome. However, regardless of the gene, the main cause of BBS is abnormal structure and / or impaired function of the so-called primary cilia. Cilia are thin, hair-like structures resembling protrusions. They are found on the surface of almost all cells in our body. There are different types of cilia with different functions. The so-called primary cilia, whose task is to transfer information between cells. They act a bit like radio antennas that send and receive messages from one cell to another, what to do and how to react. Primary cilia are responsible for transmitting data such as the type and level of chemical substances in the urine, the perception of smell, taste and balance.

Bardett-Biedl syndrome is not the only disease caused by defects in cilia. Others are, for example, very similar to BBS - the Laurence-Moon syndrome, as well as the Joubert syndrome, the Meckel-Bruber syndrome, and the Senior-Loken syndrome.

In BBS, this intercellular communication is disrupted due to defective cilia, which contributes to many birth defects and symptoms.

Bardet-Biedl syndrome: symptoms

BBS is diagnosed on the basis of genetic tests revealing mutations within specific genes, as well assets of traits: main (large) and secondary (small). A person is considered to have BBS if he or she has at least three main features and at least two secondary features.

The main features of the BBS team are:

  • Obesity.It appears in infancy in people with BBS. It is wrongly assumed that it is the result of an improper diet and the parents' blame for overfeeding the child. Meanwhile, excessive appetite and its effect in the form of excess body weight are one of the main symptoms of this serious genetic disease. As people get older, obesity, the so-called obesity, is the most common in people with BBS. abdominal, where fat accumulates around the torso and abdomen. It can lead to, inter alia, fatty liver and type 2 diabetes.
  • Retinal pigment degeneration. Unfortunately incurable. A person with this condition usually loses the ability to see in early adulthood.

How is BBS diagnosed in children? Most often based on early obesity and retinal pigment degeneration.

  • Polydactyly is the name of a birth defect in which extra toes grow on the hands and feet. They are usually removed shortly after the baby is born and are not always associated with BBS.
  • Hypogonadism in men, a defect of the male reproductive system. It is based on the fact that the testes (male gonads) do not produce hormones or gametes (sperm).
  • Delay in intellectual development. Some children with BBS have learning difficulties and need extra support at school.
  • Defects and dysfunctions of the kidneys. With BBS, cystic kidney degeneration most often occurs before delivery or in early childhood.
Important

Polycystic kidney disease is the most serious complication of Bardet-Biedl syndrome. It is the most common cause of premature death in people with BBS. Drugs and a he althy lifestyle can slow down the rate at which the kidneys fail. In many cases, however, dialysis and a kidney transplant will eventually be necessary. Therefore, a patient with BBS must undergo regular kidney check-ups in order to start treatment early.

The secondary features of the BBS team are:

  • Neurological problems - mild spasticity, i.e. excessive muscle tension (mainly legs) and limitation of their mobility, as well as ataxia, i.e. a problem with coordinating body movements and maintaining balance, which increases over time and leads tophysical disability.
  • High blood pressure.
  • Dental anomalies - small mandible, small teeth, short teeth, tooth crowding, hypodontia, i.e. missing some teeth, as well as poor root formation and high palate.
  • Successive congenital defects of fingers and toes - fingers too short (brachydactyly) or fused together (syndactyly).
  • Eyesight defects - strabismus, cataracts, astigmatism, "lazy eye".
  • Slight growth of the child in relation to the parents.
  • Heart defects, e.g. left ventricular hypertrophy.
  • Flat, wide feet, no curves.
  • Lack of sense of smell - the so-called anosmia.
  • Problems with the thyroid gland.

The symptoms of BBS may appear in different people with varying degrees of severity. While, for example, some children with BBS have problems with acquiring new knowledge, in others the intelligence quotient (IQ) is well above the norm. Such disproportions are also noticeable in children with BBS who are siblings.

Bardet-Biedl syndrome: treatment

BBS is incurable at present. A cure for BBS is under development, but there is still a long way to go. For now, researchers are trying to understand the cellular mechanisms that ultimately cause BBS. Drug research is conducted in three areas:

  • stem cell therapy - how to get new cells into the body without the defective BBS gene, which will multiply and replace damaged cells?
  • gene therapy - how to replace a faulty gene inside cells?
  • suppression therapy - how to limit the functioning of faulty genes?

While there is no cure for BBS, that doesn't mean there is nothing that can be done to help BBS patients. However, medical interventions are about alleviating the symptoms and side effects of the condition. For example, obesity is treated with conservative methods, i.e. with appropriate diet and physical activity, in order to prevent the development of the disease and the occurrence of he alth and life-threatening complications. The extra toes are removed and the fused toes are separated, which, for example, enables the correct positioning of the foot in the shoe and better movement. Developmental disorders are eliminated during therapeutic classes for children and adults with intellectual disabilities.

Worth knowing

Experts emphasize that if BBS is diagnosed in early infancy, the greater the chances of providing the child with medical care by a therapeutic team. However, they admit that the disease is so rare that many paediatricians have never encountered a patient with BBS throughout their careers.

Prepared on the basis of:-"Bardet-Biedl Syndrom. A guide for patients" - Dr Timothy G. Barrett - www.euro-wab.org- Bardet Biedl Syndrome Family Association - https: //www.bardetbiedl. org

Important

Poradnikzdrowie.pl supports safe treatment and a dignified life of people suffering from obesity. This article does not contain discriminatory and stigmatizing content of people suffering from obesity.

About the authorMagdalena Gajda A specialist in obesity disease and obesity discrimination of people with diseases. President of the OD-WAGA Foundation of People with Obesity, Social Ombudsman for the Rights of People with Obesity in Poland and a representative of Poland in the European Coalition for People Living with Obesity. By profession - a journalist specializing in he alth issues, as well as a PR, social communication, storytelling and CSR specialist. Privately - obesity since childhood, after bariatric surgery in 2010. Starting weight - 136 kg, current weight - 78 kg.

OD-WAGA Foundation

Category:

Obesity