Alström Syndrome
Patient Information
Characteristics
Background and History
This syndrome is a rare multisystem disorder named after the Swedish psychiatrist Carl Henry Alström who first described it in 1959.
Clinical Correlations
Among the earliest signs of this multisystem disease are loss of vision, obesity, heart malfunction, and hearing loss, all of which may be apparent in the first few months of life. The loss of vision is progressive and results in blindness by the age of 20 years. Some developmental delays occur early but mental function is normal. Progressive scarring in the liver, lungs, and kidneys may lead to organ failure. Type 2 diabetes mellitus results from resistance to insulin action while a variety of other metabolic and physical defects can occur from the lack of response to other hormones. The skin in body folds often becomes dark, velvety and thickened. Most individuals are short in stature.
Genetics
Inheritance
This disorder is caused by mutations in a gene located on chromosome 2. It is an autosomal recessive disorder requiring the inheritance of two mutations, one from each parent. Such parents, who are called carriers and are clinically normal, have a risk for this to occur of 25% for each child.
Pedigree
Autosomal recessive
In order for autosomal recessive disorders to be expressed, offspring generally must inherit two mutations, one from each carrier parent. Carriers with only one mutation, such as the parents, do not have clinical disease. Note that carrier parents can expect that 1 in 4 children (25%) will inherit both mutations and have the disorder, 2 in 4 children (50%) will be carriers like their parents, while 1 in 4 children (25%) inherit neither mutation.
In order for autosomal recessive disorders to be expressed, offspring generally must inherit two mutations, one from each carrier parent. Carriers with only one mutation, such as the parents, do not have clinical disease. Note that carrier parents can expect that 1 in 4 children (25%) will inherit both mutations and have the disorder, 2 in 4 children (50%) will be carriers like their parents, while 1 in 4 children (25%) inherit neither mutation.
Diagnosis and Prognosis
The constellation of clinical features is rather typical and often the pediatrician or family doctor can make the diagnosis based on these alone. Of course, gene studies can confirm this. No effective treatment is available for the disease and many patients die relatively young from organ failure.
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