What is the official name of the HCFC1 gene?
The official name of this gene is “host cell factor C1.”
HCFC1 is the gene's official symbol. The HCFC1 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 HCFC1 gene?
The HCFC1 gene provides instructions for making a protein, called HCF-1, that helps regulate the activity of other genes. HCF-1 interacts with proteins called transcription factors, which attach (bind) to specific regions of DNA and help control the activity of particular genes.
A specific function of the HCF-1 protein is to control the activity of genes involved in the processing of vitamin B12 (also known as cobalamin), particularly the MMACHC gene. This gene plays a role in the conversion of vitamin B12 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.
HCF-1 helps regulate genes that are important in other cellular processes, such as progression of cells through the step-by-step process it takes to replicate themselves (called the cell cycle). This protein also plays a role in the distribution of cells in developing tissues and organs, including the brain.
How are changes in the HCFC1 gene related to health conditions?
- methylmalonic acidemia with homocystinuria - caused by mutations in the HCFC1 gene
- At least six HCFC1 gene mutations have been identified in individuals with methylmalonic acidemia with homocystinuria, cblX type, one form of a disorder that causes developmental delay, eye defects, neurological problems, and blood abnormalities. Individuals with this form also have severe abnormalities in the development of the skull and face (craniofacial abnormalities). These mutations occur in regions of the protein that help it to interact with other proteins. It is thought that changes in these regions prevent HCF-1 from interacting with transcription factors, which disrupts normal gene activity. Impairment of MMACHC gene activity, in particular, prevents normal processing and transport of vitamin B12, impeding production of both 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. Neurological and developmental problems are especially severe in individuals with cblX type, in part due to disruption of the activity of other genes normally regulated by the HCF-1 protein.
- other disorders - caused by mutations in the HCFC1 gene
- Mutations in the HCFC1 gene have also been found in individuals with X-linked intellectual disability. These individuals have delayed development and other neurological problems but do not show other features of methylmalonic acidemia with homocystinuria, cblX type. TheHCFC1 gene mutations lead to production of an HCF-1 protein with reduced function. Partial reduction in this protein's function appears to disrupt normal brain development, leading to the features of X-linked disability, but does not severely impact vitamin B12 processing.
Where is the HCFC1 gene located?
Cytogenetic Location: Xq28
Molecular Location on the X chromosome: base pairs 153,947,557 to 153,971,833
(Homo sapiens Annotation Release 107, GRCh38.p2) (
The HCFC1 gene is located on the long (q) arm of the X chromosome at position 28.
More precisely, the HCFC1 gene is located from base pair 153,947,557 to base pair 153,971,833 on the X chromosome.
See How do geneticists indicate the location of a gene? in the Handbook.
Where can I find additional information about HCFC1?
You and your healthcare professional may find the following resources about HCFC1 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 HCFC1 gene or gene products?
- host cell factor 1
- protein phosphatase 1, regulatory subunit 89
- VP16-accessory 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 HCFC1?
acids ; amino acid ; cell ; cell cycle ; cholesterol ; CoA ; cobalamin ; cofactor ; craniofacial ;developmental delay ; disability ; DNA ; enzyme ; gene ; methionine ; neurological ; phosphatase ;progression ; protein ; subunit ; toxic ; transcription ; vitamin B12
You may find definitions for these and many other terms in the Genetics Home Reference Glossary.
See also Understanding Medical Terminology.
References (8 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