Diabetes and Alström Syndrome

Alström syndrome is a rare genetic disorder that affects numerous body systems. Most of the signs and symptoms of this disorder appear in infancy or early childhood, although some symptoms appear quite later in life.

Alström syndrome is characterised by a progressive loss of both vision and hearing, a form of cardiovascular disease that leads to enlargement and weakening of the heart muscle (which is also known as dilated cardiomyopathy), type 2 diabetes, obesity, and short stature.

This syndrome can lead to serious, life-threatening medical problems that involve the kidneys, liver, lungs, and bladder. Some individuals who develop this condition also are affected by a skin condition known as acanthosis nigricans, which causes the skin in the folds and creases of the body to become dark, thick, and velvety. The signs and symptoms of this disorder drastically vary in severity and not every affected individual has the same characteristic features of this disorder.

Type 2 Diabetes Mellitus and Alström Syndrome

Acute insulin resistance, impaired glucose tolerance, and hyperinsulinemia often manifest in very early childhood and are often accompanied by acanthosis nigricans. Even when they are matched for pubertal stage and body composition, those with Alström syndrome are more severely insulin resistant in comparison with controls. Type 2 diabetes mellitus often develops in early childhood, adolescence, or adulthood, with a mean age of onset being 16 years.

A reduced intake of carbs may prove to be more effective than restriction of fats when it comes to controlling of hyperglycaemia as well as hyperinsulinemia in a subset of individuals with this syndrome. Some researchers described moderation of hyperinsulinemia with stringent restriction of calories in one study involving a young child with Alström syndrome. 

Metformin and dipeptidyl peptidase 4 (DPP4) inhibitors have been proven to be effective in a few individuals. That said, hyperglycaemia could be intractable, thus needing insulin to achieve optimal glycaemic control.

In stark contrast to the general population, the onset of type 2 diabetes mellitus seems to be unrelated to the degree of obesity. In addition, adequate protection from clinical peripheral sensory neuropathy is recommended.

Some of the other key features of Alström syndrome are mentioned below:

• Retinal Degeneration

This is often the foremost feature of Alström syndrome that is noticeable. Children tend to have nystagmus (or wobbly eyes) and photophobia (which is extreme sensitivity to light). Poor vision could be present even in young babies, and gradual vision loss can eventually lead to blindness.

• Loss of Hearing

This is generally noticed before the individual reaches 10 years of age. The severity of hearing loss in this disorder varies considerably.

• Cardiomyopathy

In this condition, the heart fails to pump blood as efficiently as it should. It can significantly improve (though not completely), with a possible recurrence in later life.

• Obesity

Children and young individuals with Alström syndrome have lower energy needs and are generally less active in comparison with their peer group. Hence, their risks of developing obesity are quite high. This considerable gain in weight tends to be much lesser in severity in later life type 2 diabetes.

• Kidney (or Renal) Failure

This may be quite acute (occurring rapidly) or chronic (occurring over an extended period). There are numerous reasons why the kidneys eventually fail. One of these reasons is diabetes.

• Orthopaedic and Rheumatology Problems

Individuals with Alström syndrome may develop problems with both their bones and joints. These problems may include spondylitis (which is characterised by excessive thickening of the spine), curvature of the spine, short stature, and even arthritis. Other health problems such as hypogonadism (characterised by defects in the reproductive system), low testosterone, undescended testes, polycystic ovaries, acanthosis nigricans (or dark skin patches), and underactive thyroid may also be present.

To Sum It All Up:

Alström syndrome is an extremely rare autosomal recessive genetic disorder that is characterised by hearing loss, cone-rod dystrophy, childhood obesity, hyperinsulinemia, insulin resistance, type 2 diabetes, hypertriglyceridemia, cardiomyopathy, short stature in adulthood, and progressive renal, hepatic, and pulmonary dysfunction. Symptoms first appear during infancy, and progressive multi-organ pathology development leads to a reduction in life expectancy. Variability when it comes to age of onset, as well as the severity of signs and clinical symptoms (even within families), is most likely because of genetic background.

References:

• https://medlineplus.gov/genetics/condition/alstrom-syndrome/#:~:text=Alstr%C3%B6m%20syndrome%20is%20characterized%20by,diabetes)%2C%20and%20short%20stature.
• https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3137007/
• https://www.diabetes.org.uk/diabetes-the-basics/other-types-of-diabetes/alstrom-syndrome