Alstrom syndrome is a rare autosomal recessive disorder characterized by cone-rod dystrophy with secondary nystagmus and photodysphoria, truncal obesity, progressive bilateral sensorineural hearing loss, dilated or restrictive cardiomyopathy, insulin resistance syndrome, and multiple organ failure. Acanthosis nigricans, a skin disorder characterized by dark, velvety skin in body folds and creases, is usually seen in patients. The first manifestations of this condition can appear as early as from birth to 15 months. With increasing age, the range of manifestations increases, till it encompasses multiple organ failure, involving the liver, kidneys, bladder, and lungs. More than 60% of patients with this condition eventually develop cardiac failure due to dilated or restrictive cardiomyopathy. Alstrom syndrome is extremely rare, with only about 500 cases being discovered worldwide. The reported patients have a predominance of English kindreds.
Alstrom syndrome is diagnosed based on its clinical features. Differential diagnoses include Laurence-Moon or Bardet-Bieldl syndromes. Molecular diagnosis is technically feasible for this condition. In approximately 70-80% of patients of Northern European descent, and about 40% of patients worldwide, genetic testing can detect causal mutations. The life span of patients with this condition rarely exceeds the age of 40-years. There is no specific therapy for Alstrom syndrome. However, early diagnosis and intervention may moderate the progression of the disease and may improve the length and quality of the patient's life. These interventions include diabetes and cardiac medications, the use of hearing aids, and thyroid hormone replacement.
Alstrom syndrome is transmitted in an autosomal recessive manner. Mutations in ALMS1 gene are known to cause this condition. The exact function of the ALMS1 protein is not known. However, it has been shown to express ubiquitously in almost all tissue types and localize subcellularly. It has been proposed that ALMS1 may be involved in the functioning of centrosomes or basal bodies.
