What is the official name of the ABCD4 gene?
The official name of this gene is “ATP binding cassette subfamily D member 4.”
ABCD4 is the gene's official symbol. The ABCD4 gene is also known by other names, listed below.
Read more about gene names and symbols on the About page.
What is the normal function of the ABCD4 gene?
The ABCD4 gene provides instructions for making a protein that is involved in the conversion of vitamin B12 (also known as cobalamin) into one of two molecules, adenosylcobalamin (AdoCbl) or methylcobalamin (MeCbl). AdoCbl is required for the normal function of an enzyme known as methylmalonyl CoA mutase. This enzyme helps break down certain protein building blocks (amino acids), fats (lipids), and cholesterol. AdoCbl is called a cofactor because it helps methylmalonyl CoA mutase carry out its function. MeCbl is also a cofactor, but for an enzyme known as methionine synthase. This enzyme converts the amino acid homocysteine to another amino acid, methionine. The body uses methionine to make proteins and other important compounds.
The ABCD4 protein is found in the membrane that surrounds cell structures called lysosomes. Lysosomes are compartments within cells in which enzymes digest and recycle materials. In the lysosomal membrane, the ABCD4 protein interacts with another protein called LMBD1 (produced from the LMBRD1 gene). Together, these two proteins transport vitamin B12 out of lysosomes, making it available for further processing into AdoCbl and MeCbl.
Does the ABCD4 gene share characteristics with other genes?
The ABCD4 gene belongs to a family of genes called ABC (ATP-binding cassette transporters).
A gene family is a group of genes that share important characteristics. Classifying individual genes into families helps researchers describe how genes are related to each other. For more information, see What are gene families? in the Handbook.
How are changes in the ABCD4 gene related to health conditions?
- methylmalonic acidemia with homocystinuria - caused by mutations in the ABCD4 gene
- At least five mutations in the ABCD4 gene have been found to cause methylmalonic acidemia with homocystinuria, cblJ type, one form of a disorder that causes developmental delay, eye defects, neurological problems, and blood abnormalities. ABCD4 gene mutations involved in this condition lead to production of an abnormal ABCD4 protein that is unable to function. A shortage of functional ABCD4 protein prevents the release of vitamin B12 from lysosomes, so the vitamin is unavailable for the production of AdoCbl and MeCbl. Because both of these cofactors are missing, the enzymes that require them (methylmalonyl CoA mutase and methionine synthase) do not function normally. As a result, certain amino acids, lipids, and cholesterol are not broken down and homocysteine cannot be converted to methionine. This dual defect results in a buildup of toxic compounds as well as homocysteine, and a decrease in the production of methionine within the body. This combination of imbalances leads to the signs and symptoms of methylmalonic acidemia with homocystinuria.
Where is the ABCD4 gene located?
Cytogenetic Location: 14q24.3
Molecular Location on chromosome 14: base pairs 74,285,277 to 74,303,064
(Homo sapiens Annotation Release 107, GRCh38.p2) (
The ABCD4 gene is located on the long (q) arm of chromosome 14 at position 24.3.
More precisely, the ABCD4 gene is located from base pair 74,285,277 to base pair 74,303,064 on chromosome 14.
See How do geneticists indicate the location of a gene? in the Handbook.
Where can I find additional information about ABCD4?
You and your healthcare professional may find the following resources about ABCD4 helpful.
You may also be interested in these resources, which are designed for genetics professionals and researchers.
What other names do people use for the ABCD4 gene or gene products?
- 69 kDa peroxisomal ABC-transporter
- ATP-binding cassette, sub-family D (ALD), member 4
- ATP-binding cassette sub-family D member 4
- peroxisomal membrane protein 69
- PMP70-related protein
See How are genetic conditions and genes named? in the Handbook.
Where can I find general information about genes?
The Handbook provides basic information about genetics in clear language.
- What is DNA?
- What is a gene?
- How do genes direct the production of proteins?
- How can gene mutations affect health and development?
These links provide additional genetics resources that may be useful.
What glossary definitions help with understanding ABCD4?
acids ; amino acid ; ATP ; cell ; cholesterol ; CoA ; cobalamin ; cofactor ; developmental delay ;enzyme ; gene ; methionine ; neurological ; protein ; toxic ; vitamin B12
You may find definitions for these and many other terms in the Genetics Home Reference Glossary.
See also Understanding Medical Terminology.
References (5 links)
The resources on this site should not be used as a substitute for professional medical care or advice. Users seeking information about a personal genetic disease, syndrome, or condition should consult with a qualified healthcare professional. See How can I find a genetics professional in my area? in the Handbook