Alstrom Syndrome is one of the Mendelian disorders discussed on the website Online Mendelian Inheritance in Man (OMIM) with the OMIM number 203800. Alstrom Syndrome (ALMS) is a rare disorder in man and is often confused with Bardet-Biedl syndrome because they have almost similar symptoms (Alstrom et al., 1959). It is caused by homozygous or compound homozygous mutation in the ALMS1 gene on chromosome 2p 13. As described by Collin et al. (2002) and Marshall et al. (2007), the key symptoms of Alstrom Syndrome include blindness, sensorineural and hearing loss. Childhood obesity could also be seen in children carriers. In addition, health problems such as pulmonary dysfunction, hepatic and urologic dysfunction, and renal failure are imminent as one grows old. Therefore, this article attempts to highlight Alstrom Syndrome in terms of causes, diagnosis, localization of gene and symptoms. In this regard, various references that have played a major role towards the discovery of Alstrom Syndrome will also be discussed herein.
Alstrom Syndrome is an autosomal recessive disease that results into multi-organ dysfunction. It is associated with metabolic diseases such as obesity and hyperinsulinemia. Symptoms such as heart failure are observed in the first few weeks after birth and they later become more severe in later stages of life: adolescence and adulthood. Blindness and obesity, also observed at infancy, are more pronounced in late adulthood. Although ALMS and Bardet-Biedl Syndrome have a lot of clinical symptoms in common, studies show that the two disorders are far much different in terms of their gene map locus. The occurrence of ALMS in the body affects several body parts, including head, neck, chest, respiratory system, abdomen, hair, skin, and nails. ALMS is the phenotype, while ALMS1 gene mutilation is the genotype that occurs on the chromosome 2p 13.
Causes and Diagnosis
ALMS1 gene has been found to be the causative factor of Alstrom Syndrome. It is caused by homozygous or heterozygous mutation of the ALMS1 gene on the chromosome 2p 13. Marshall et al. (2007) found out that there are 79 mutations in the ALMS1 gene making chromosome 2p 13 a hotspot for mutilation. Due to the recessive nature of ALMS, both genes must come from both parents. In common practice, the disorder is usually detected at infancy, but there is also likelihood of its clinical observation at later stages.
Mapping and Inheritance
The gene map locus is an important facet in the study of ALMS. A study conducted by Collin et al. (1997) in a large French Acadian Kindred showed that the gene was localized on locus 2p 14-p 13. However, a study conducted on an Algerian family by Macari et al. (1998) refined the localization to locus 2p 13-p 12 after which Collin et al. (1999) later confirmed the gene map locus for ALMS as 2p 13. A study conducted by Alstrom et al. (1959) asserts that inheritance of ALMS occurs through “autosomal recessive inheritance,” as did Goldstein and Fialkow (1973).
Symptoms. The following are some of the symptoms associated with Alstrom Syndrome:
- Blindness, mostly evident during infancy period
- Obesity, observed during infancy
- Metabolic disorders such as elevated serum triglyceride and hyperuricemia
- Dilated cardiomyopathy ages 3 weeks to 4 months and Cardiomyopathy at the age of 36-37 years
- Pigmentary retinopathy
- Chronic hepatitis
- Deficiency of growth hormone
- Acanthosis nigricans
- Diabetes mellitus and diabetes insipidus
- Presence of liver cirrhosis at the age of twenties
- Presence of hepatic dysfunction and hypertension
- Mitochondrial disorder
- Multinodular goiter
- Growth hormone deficiency
- Hyperostosis frontalis interna.