Inherited metabolic diseases

Inherited metabolic diseases are a large class of genetic disorders. Most of these disorders are due to defects of single genes that code for enzymes involved in the metabolism of cells. These diseases can be categorized into different types based on the specific metabolic pathway affected.

Overview

Inherited metabolic diseases, also known as inborn errors of metabolism, are caused by mutations in specific genes that result in the production of dysfunctional enzymes or transport proteins. These mutations can be inherited in an autosomal recessive, autosomal dominant, or X-linked recessive manner. The result is a block in a metabolic pathway leading to an accumulation of substrates or a deficiency of the end product. This can lead to a variety of clinical symptoms, often involving the nervous system, muscular system, or endocrine system.

Classification

Inherited metabolic diseases can be classified into several categories, including:

• Amino acid disorders: These disorders are caused by defects in the breakdown of amino acids, the building blocks of proteins. Examples include phenylketonuria and maple syrup urine disease.

• Carbohydrate disorders: These disorders affect the breakdown of carbohydrates, which are the body's primary source of energy. Examples include galactosemia and glycogen storage disease.

• Fatty acid oxidation disorders: These disorders affect the body's ability to break down fats for energy. Examples include medium-chain acyl-CoA dehydrogenase deficiency.

• Lysosomal storage disorders: These disorders are caused by defects in lysosomal enzymes, leading to an accumulation of toxic substances in the body's cells. Examples include Gaucher's disease and Fabry disease.

• Mitochondrial disorders: These disorders are caused by defects in the mitochondria, the energy-producing structures within cells. Examples include Leigh syndrome and MELAS syndrome.

Diagnosis and Treatment

Diagnosis of inherited metabolic diseases often involves biochemical testing, genetic testing, and imaging studies. Treatment varies depending on the specific disorder and may include dietary modifications, medications, enzyme replacement therapy, and in some cases, organ transplantation.

See Also

• Genetic disorder
• Metabolism
• Enzyme