Alström Syndrome
Description
Alström syndrome is a rare, autosomal recessive genetic disorder that affects multiple organ systems. Characterized by a wide range of symptoms, including vision loss, obesity, diabetes, and heart problems, Alström syndrome presents unique challenges for individuals and their families. This blog explores the complexities of this condition, shedding light on its causes, diagnosis, management strategies, and the remarkable resilience of those living with it.
Genes Involved
Genes Involved in Alström Syndrome
Alström syndrome is caused by mutations in a single gene called ALMS1. This gene provides instructions for creating a protein that plays a crucial role in various cellular processes, including cell growth, movement, and signaling. When mutations occur in this gene, they disrupt these processes, leading to the development of Alström syndrome.
Recognizing the Signs and Symptoms
Recognizing the Signs and Symptoms of Alström Syndrome
Alström syndrome typically presents with a diverse range of symptoms, often emerging during childhood. Key signs and symptoms include:
- Vision Loss: Retinitis pigmentosa, a progressive eye condition that causes night blindness and peripheral vision loss.
- Obesity: Early onset of obesity, often starting in early childhood, with a significant impact on overall health.
- Diabetes: Development of insulin resistance and type 2 diabetes, typically in adolescence or early adulthood.
- Heart Problems: Cardiomyopathy (weakening of the heart muscle) and other cardiac issues can occur.
- Hearing Loss: Sensorineural hearing loss, affecting the inner ear, may also develop.
- Kidney Issues: Altered kidney function, potentially leading to chronic kidney disease.
- Liver Problems: Hepatic dysfunction, impacting the liver‘s ability to function properly.
- Growth Retardation: Individuals with Alström syndrome may experience slowed growth and be shorter than average.
- Delayed Puberty: Delayed or absent puberty can occur.
- Gastrointestinal Issues: Gastrointestinal problems, including constipation, can arise.
- Skin Problems: Skin abnormalities, such as keratosis pilaris (small, rough bumps on the skin) can be present.
Causes
Causes of Alström Syndrome
Alström syndrome is an autosomal recessive genetic disorder, meaning that an individual must inherit two copies of the mutated ALMS1 gene, one from each parent, to develop the condition. If an individual inherits only one copy of the mutated gene, they are considered a carrier and may not show any symptoms. The chances of inheriting the condition depend on the family history and the prevalence of the mutated gene within a specific population.
Inheritance/recurrence risk
Inheritance and Recurrence Risk
Alström syndrome follows an autosomal recessive inheritance pattern. This means that both parents must carry the mutated gene for their child to inherit the condition. If both parents are carriers, there is a 25% chance that their child will inherit two copies of the mutated gene and develop Alström syndrome. There is a 50% chance that their child will inherit one copy of the mutated gene and be a carrier, and a 25% chance that their child will inherit two normal copies of the gene and not be affected by the condition.
Recurrence risk refers to the probability of a couple having another child with Alström syndrome if they have already had one child with the condition. If both parents are carriers, the recurrence risk for each subsequent pregnancy is 25%.
