Alstrom syndrome

Symptoms

Vision loss is often the first symptom to become apparent, usually from birth as a result of cone-rod dystrophy. Cone-rod dystrophy is a form of retinal dysfunction where the cells in the retina (cones and rods) that convert light into nerve impulses gradually deteriorate causing progressive vision loss. In addition to vision loss, individuals with Alstrom syndrome may develop photophobia, severe sensitivity of the eyes to light and nystagmus, rapid, involuntary movement of the eyes. Some individuals may also develop cataracts, clouding of the lens of the eye.  In most cases, vision becomes progressively worse through the first and second decade of life which may result in blindness in the mid-teens. However, the progression and degree of vision loss among individuals with the condition will vary.

Hearing loss is another symptom of Alstrom syndrome which often affects individuals in the first decade of life. This is caused by sensorineural hearing loss where the ability of the auditory nerves to transmit sensory input to the brain is impaired.  In approximately 70% of patients, sensorineural hearing loss tends to affect both ears.  The degree of hearing loss may be mild to moderate or may progress to moderately severe or severe by the end of the first and second decade.  Some adults go on to have cochlear implants.

Birth weight is normal in infants with Alstrom syndrome. However, excessive eating beyond the normal need to satisfy hunger (hyperphagia) and rapid weight gain may occur during the first few years of life. Some patients may go on to develop childhood truncal obesity where fat is disproportionally distributed on the chest and abdomen rather than the arms and legs. The majority of children have a rapid growth, with height above the 50th percentile before puberty but final adult height frequently below the 5th percentile.

Cause

Alstrom syndrome is an ultra-rare genetic condition affecting at least 263 cases in Europe, including 89 in the UK.

It is caused by changes in the ALMS1 gene. Alstrom syndrome is a recessive condition meaning both parents must carry 1 copy of the ALMS1 gene with a significant change to have an affected child. There is then a 1 in 4 chance of having an affected child with each pregnancy. More information about inheritance patterns is available from the About Inherited Sight Loss section of our website: Inheritance patterns – Retina UK.

Treatment

There is no cure or condition specific treatment for   Alstrom syndrome. However, there are effective treatments for some of the symptoms such as heart failure, diabetes and obesity.. Sensitivity to bright light (photophobia) can be treated by wearing dark tinted glasses. Hearing aids and cochlear implants can be used to support  hearing loss.  Treatment for Alstrom syndrome also involves following a healthy, balanced diet as well as regular physical exercise to keep weight under control and help manage type 2 diabetes.

People diagnosed with Alstrom Syndrome in the UK can access a highly specialised service in Birmingham. Birmingham Women’s and Children’s Hospital, the Queen Elizabeth Hospital, Birmingham and Alstrom Syndrome UK work in partnership to deliver multi-disciplinary clinics for children, young people and adults.

Retina UK welcomes families affected by Alstrom syndrome to its community. However, we don’t have specialist knowledge about symptoms other than sight loss. These organisations may be able to help:

• Alstrom Syndrome UK
  Tel: 07970 071675
  Email: catherine.lewis@alstrom.org.uk
  Website: Alstrom Syndrome
• Clinical management guidelines for Alström syndrome