Alström syndrome

Genetic testing of the ALMS1 gene is available for Alström syndrome. Although genetic testing is not necessary to make a diagnosis of Alström syndrome, it can be helpful to confirm a diagnosis. If a mutation is not identified in both copies of the ALMS1 gene of an individual suspected to have Alström syndrome, it does not rule out the diagnosis.

Alström syndrome is diagnosed based on clinical findings (signs and symptoms), medical history, and family history. Making a diagnosis can be complicated by the variation in age of symptom onset from one individual to another. Genetic testing is not necessary to make the diagnosis of Alström syndrome, although it can be useful to confirm a diagnosis.

A table listing diagnostic criteria categorized by age is available through GeneReviews.

Alström syndrome is inherited in an autosomal recessive manner. This means that to be affected, a person must have a mutation in both copies of the ALMS1 gene in each cell.

Affected people inherit one mutated copy of the gene from each parent, who is referred to as a carrier. Carriers of an autosomal recessive condition typically do not have any signs or symptoms (they are unaffected). When 2 carriers of an autosomal recessive condition have children, each child has a:

• 25% (1 in 4) chance to be affected
• 50% (1 in 2) chance to be an unaffected carrier like each parent
• 25% (1 in 4) chance to be unaffected and not be a carrier

Progressive sensorineural hearing loss is found in 88% of individuals with Alström syndrome. About 10% of affected indivduals progress to profound deafness and must rely on sign language for communication.

In up to 70% of individuals with Alström syndrome, hearing loss becomes evident between ages one and ten years. The average age of onset is 9 years old but can range from 2 years to 25 years old. Hearing loss may progress to be more severe by the end of the first to second decade.

The prognosis for Alström syndrome varies depending on the progression of symptoms, specifically heart and kidney disease. The lifespan and overall quality of life for individuals with Alström syndrome can be improved by early diagnosis, treatment, surveillance, and proper management of symptoms.

There is no specific treatment for Alström syndrome. Treatment is focused on managing the symptoms present in each individual. This may involve a team of specialists including but not limited to: pediatricians, cardiologists, audiologists (hearing specialists), ophthalmologists, endocrinologists, and orthopaedists.

Treatment may include:

• Specially-tinted, prescription glasses and vision aids to assist with vision loss
• Hearing aids and cochlear implants for hearing loss
• Dietary measures, exercise programs, and oral medications and/or insulin to control diabetes
• ACE inhibitors and other medications to manage heart and kidney problems with some individuals requiring a kidney or heart transplant
• Hormone therapy if the male testes or female ovaries produce lower than average levels

Alstrom Syndrome International offers a listing of recommended monitoring guidelines on their website. Click on the link for more information.

Alstrom Syndrome International, a supporting organization, offers information on Alström syndrome