Bardet-Biedl syndrome 14

Bardet-Biedl Syndrome 14 (BBS14) Description

Bardet-Biedl syndrome-14 (BBS14) is a rare genetic disorder that affects multiple systems in the body. It is characterized by a combination of symptoms, including:

• Retinitis pigmentosa: A progressive visual impairment due to cone-rod dystrophy [1][3][4]
• Obesity and related complications: Early-onset obesity, which can lead to various health issues [5][10]
• Mental retardation: Cognitive impairment is a common feature of BBS14 [2][6][13]
• Renal disease: Kidney abnormalities and renal parenchymal disease are also associated with BBS14 [3][7]

BBS14 is an autosomal recessive ciliopathy, meaning that it is inherited in an autosomal recessive pattern. This means that a person must inherit two copies of the mutated gene (one from each parent) to develop the condition.

It's worth noting that Bardet-Biedl syndrome-14 is one of 14 different genes associated with BBS, and the symptoms can vary significantly between individuals [2][8].

References:

[1] Leitch et al. (2008) [2] Beales PL, Elcioglu N, Woolf AS, Parker D, Flinter FA. (2012) [3] Bardet-Biedl syndrome 14 is an autosomal recessive ciliopathy characterized by retinitis pigmentosa, obesity, mental retardation, and renal disease. [4] Farag TI, Teebi AS: High incidence of Bardet Biedl syndrome among the Bedouin. (1999) [5] Forsyth R, Gunay-Aygun M. Bardet-Biedl Syndrome Overview. 2003 Jul 14 [updated2023 Mar 23]. [6] Title: Bardet-Biedl syndrome 14 Definition: Bardet-Biedl syndrome-14 (BBS14) is an autosomal recessive ciliopathy with features of retinitis pigmentosa, obesity, mental retardation, and renal disease. [7] Clinical Characteristics of Bardet-Biedl Syndrome. Bardet-Biedl syndrome (BBS) is a multisystem non-motile ciliopathy primarily characterized by retinal cone-rod dystrophy, obesity and related complications, postaxial polydactyly, cognitive impairment, hypogonadotropic hypogonadism and/or genitourinary malformations, and renal malformations and/or renal parenchymal disease. [8] Clinical Characteristics of Bardet-Biedl Syndrome Bardet-Biedl syndrome (BBS) is a multisystem non-motile ciliopathy primarily characterized by retinal cone-rod dystrophy, obesity and related complications, postaxial polydactyly, cognitive impairment, hypogonadotropic ... Polycystic ovary syndrome (14.7%) 8

Bardet-Biedl syndrome (BBS) is a rare genetic disorder that affects multiple systems in the body. The signs and symptoms of BBS can vary from person to person, but here are some common ones:

• Obesity: One of the hallmark features of BBS is obesity, particularly around the abdomen [1]. This is often accompanied by hyperphagia (increased appetite) [2].
• Polydactyly: Many people with BBS have extra fingers or toes, a condition known as polydactyly [3][4].
• Intellectual disability: BBS can cause mild to moderate intellectual disability or learning disabilities [5][6].
• Vision problems: The syndrome is associated with retinitis pigmentosa, which can lead to decreased visual acuity, night blindness, photophobia, and loss of central and color vision by late childhood/early adulthood [7].
• Kidney problems: Some individuals with BBS may experience kidney failure or other renal issues.
• Hypogonadism: This is a condition where the sex glands (ovaries in females and testes in males) do not produce enough hormones, leading to delayed puberty or infertility.

It's essential to note that each person with BBS may exhibit a unique combination of these symptoms, and the severity can vary widely from one individual to another.

Bardet-Biedl syndrome (BBS) 14 can be diagnosed through a combination of clinical evaluation and genetic testing.

• Clinical Features: The diagnosis of BBS 14 is based on the presence of four major clinical features or three major and two minor clinical features. These features include:
  • Rod cone dystrophy [10]
  • Obesity, particularly truncal obesity [8, 9]
  • Genital anomalies [4]
  • Renal anomalies [4]
• Genetic Testing: Genetic testing can help confirm the diagnosis of BBS 14 by identifying mutations in one of the associated genes. The Invitae Bardet-Biedl Syndrome Panel analyzes genes that are associated with BBS, including those responsible for BBS 14 [8].
• Diagnostic Criteria: A clinical resource notes that genetic testing has improved over the years, prompting a revision of diagnostic criteria to take into account clinical manifestations and genetic findings [3].

It's worth noting that genetic testing can also help identify siblings who may be carriers or have the condition themselves. However, the diagnosis is ultimately based on a combination of clinical evaluation and genetic testing.

References: [3] H Dollfus · 2024 · Cited by 3 — Genetic testing has progressively improved in the last years prompting for a revision of the diagnostic criteria taking into account clinical ... [8] The Invitae Bardet-Biedl Syndrome Panel analyzes genes that are associated with Bardet-Biedl Syndrome (BBS), which is characterized by truncal obesity, ... [9] BBS can be diagnosed based on clinical features. Genetic testing can help provide additional evidence to support diagnosis and may help identify siblings with ...

Treatment Options for Bardet-Biedl Syndrome (BBS)

Bardet-Biedl syndrome (BBS) is a rare genetic disorder associated with severe obesity, intellectual disability, and other systemic features. While there's currently no cure for BBS, various treatment options are available to help manage its symptoms.

Approved Drug Treatment: Setmelanotide

One of the approved drug treatments for BBS is setmelanotide, a melanocortin 4 receptor agonist. It has been shown to be effective in reducing hunger and promoting weight loss in patients with genetically confirmed BBS [5]. A study published in 2022 found that setmelanotide was associated with greater weight loss and hunger reduction than placebo after 14 weeks of treatment [9].

Other Potential Therapies

In addition to setmelanotide, other potential therapies for BBS are being explored. These include gene replacement therapy, readthrough therapy, exon skipping therapy, and genome editing [8]. These emerging treatments hold promise for improving the management of BBS symptoms in the future.

Multidisciplinary Treatment Approach

Given the complex nature of early-onset severe obesity associated with BBS, treatment should ideally be provided by a multidisciplinary team with medical providers, nutritionists, psychologists, and other specialists [7]. This comprehensive approach can help address the various aspects of the condition and improve patient outcomes.

References:

• [5] Setmelanotide was approved for hunger control in genetically confirmed Bardet-Biedl syndrome patients.
• [8] by S Ganawa · 2022 · Cited by 9 — Future therapies for BBS could include gene replacement therapy, readthrough therapy, exon skipping therapy and genome editing.
• [7] by H Dollfus · 2024 · Cited by 3 — Given the complex nature of early-onset severe obesity, treatment should ideally be provided by a multidisciplinary team with: medical providers ...
• [9] by AM Haqq · 2022 · Cited by 91 — In this multicentre, phase 3 trial, setmelanotide was associated with greater weight loss and hunger reduction than placebo after 14 weeks of treatment, with ...

Bardet-Biedl syndrome (BBS) has a complex differential diagnosis, and it can be challenging to distinguish it from other genetic obesity syndromes. Here are some conditions that should be considered in the differential diagnosis of BBS:

• Alstrom syndrome: This is another ciliopathy that presents with similar features to BBS, including obesity, insulin resistance, and kidney disease [2].
• Prader-Willi syndrome: This genetic disorder also causes severe obesity, short stature, and intellectual disability, which can be similar to the symptoms of BBS [2].
• Cohen syndrome: This rare genetic disorder presents with features such as obesity, intellectual disability, and distinctive facial features, which can overlap with those of BBS [not mentioned in context but a relevant condition]
• Obesity-related syndromes: Other conditions that cause obesity, such as leptin deficiency or MC4R mutations, should also be considered in the differential diagnosis of BBS [not mentioned in context but a relevant condition]

It's essential to note that the differential diagnosis for BBS is broad and can include various genetic and metabolic disorders. A comprehensive evaluation by a multidisciplinary team of healthcare professionals, including geneticists, endocrinologists, and nephrologists, is necessary to accurately diagnose BBS.

References: [1] - Not mentioned in context [2] - 2. Feb 21, 2024 — The differential diagnosis for BBS includes other ciliopathies, such as Alstrom syndrome, and other genetic obesity syndromes, such as Prader- ...