ABCD4 : ATP binding cassette subfamily D member 4

The ABCD4 Gene: A Gatekeeper for Vitamin B12 Metabolism

Description

The ABCD4 gene holds the blueprint for producing a vital protein that plays a crucial role in the transformation of vitamin B12, the essential nutrient commonly known as cobalamin. This protein serves as a gatekeeper, facilitating the conversion of vitamin B12 into two essential molecules: adenosylcobalamin (AdoCbl) and methylcobalamin (MeCbl).

Functions in Vitamin B12 Conversion

AdoCbl acts as a cofactor for methylmalonyl CoA mutase, an enzyme responsible for metabolizing certain amino acids, fatty acids, and cholesterol. This function is vital for maintaining cellular health and preventing the accumulation of harmful metabolites.

MeCbl, on the other hand, is a cofactor for methionine synthase, an enzyme involved in the conversion of homocysteine to methionine. Methionine is an essential amino acid used in protein synthesis and various cellular processes.

Associated Diseases

Mutations in the ABCD4 gene can disrupt the protein's function, leading to several disorders related to vitamin B12 metabolism:

• Methylmalonic acidemia (MMA): A buildup of methylmalonic acid, a harmful metabolite, caused by impaired activity of methylmalonyl CoA mutase.
• Homocystinuria: Elevated levels of homocysteine due to reduced activity of methionine synthase.
• Vitamin B12 deficiency: Impaired transport of vitamin B12 out of lysosomes, affecting the production of AdoCbl and MeCbl.

Did you Know ?

Approximately 1 in 60,000 newborns worldwide are affected by a genetic disorder related to ABCD4 gene mutations.