The HPDL gene helps cells, especially in the brain and nerves, support normal energy use and early development. This gene plays an important role in keeping movement and nerve pathways working as they should. When both copies of the HPDL gene carry harmful variants, a person can develop a rare inherited condition that may cause developmental delay, muscle stiffness, weakness, movement problems, and sometimes seizures. Symptoms often begin in infancy or childhood, although the exact pattern can vary from person to person.
What is a gene?
Genes are stretches of DNA that carry instructions your cells use to make molecules or regulate processes in the body. Some genes provide the directions for producing proteins, which are the functional parts of cells. Others mainly control when certain processes take place, where they happen, and how active they are. As a whole, genes affect how the body develops and works, and they can influence how you respond to food, stress, or medications. For a more detailed overview of this subject, you can find additional information in the LearnHub.
Overview
HPDLGene function
What if the gene works
The HPDL gene helps mitochondria, the cell’s energy centers, work properly, especially in nerve cells. This supports normal movement and brain function.
Risk
What if the gene does not work
People with pathogenic variants in the HPDL gene can develop neurologic conditions ranging from brain problems in infancy to later spasticity, weakness, and developmental delay. Milder variants may cause later symptoms, while more disruptive variants often present earlier.
Treatment
What does that mean for your treatment
No treatment or drug selection approach specific to the HPDL gene is currently established in clinical guidelines. The HPDL gene is being studied for its role in mitochondrial energy pathways, and early reports have explored coenzyme Q10 supplements in some affected people, but this remains investigational.
Conditions associated with HPDL
Gene function
What if the gene works
Much of how the HPDL gene helps cells make energy happens inside mitochondria, the parts of the cell that make energy. In simple terms, HPDL gene function centers on supporting routine energy chemistry. When this system runs well, cells can keep up with everyday demands.
The HPDL protein works in mitochondria, where cells run many energy related reactions. There, it supports routine chemical steps that help the cell use fuel.
The HPDL gene supports pathways that help cells turn nutrients into usable energy. This gives cells a steady supply of power for everyday jobs such as movement, signaling, and repair.
HPDL is involved in pathways linked to coenzyme Q10, a molecule that helps move energy inside mitochondria. This supports smooth energy flow from one step to the next.
What is a variant?
A genetic variant is a minor difference in a gene’s DNA sequence. These differences are common and help shape normal human diversity, including variation in appearance, metabolism, and the way the body responds to environmental influences. Many variants do not have any noticeable effect and are simply part of natural genetic variation. In some situations, though, a variant can change how a gene works more significantly and may contribute to or lead to a genetic condition.
Genetic variants
What if the gene does not work
Variants in the HPDL gene often make the protein unstable, alter its shape, or stop cells from making a full length protein, which helps explain how HPDL gene variants affect mitochondrial function. More disruptive variants, including those that truncate the protein, usually have a larger effect than some missense variants, which may leave partial activity. In conditions linked to the HPDL gene, this range can influence how early symptoms begin and how pronounced they are.
How variants are linked to conditions
Pathogenic variants in both copies of the HPDL gene cause a rare inherited neurologic condition often called HPDL-related neurodevelopmental disease. In published studies, conditions linked to HPDL gene variants include hereditary spastic paraplegia and leukodystrophy-like neurodevelopmental disease, often with developmental delay, progressive muscle stiffness and weakness in the legs, movement problems, seizures, and brain MRI changes.
A variant is not necessarily a diagnosis
Genetic variants are a routine part of being human and are widely seen in the general population. Most do not directly affect health and simply reflect normal human diversity. For many genes, carrying a variant associated with a condition suggests a possible link rather than a certain diagnosis, especially when several genes and environmental factors play a role. In some situations, though, one well-characterized variant in a specific gene is enough to confirm a diagnosis.
Are there things that can increase or change my risk?
For HPDL, health effects are mainly linked to the specific gene change a person is born with, and there is not broadly confirmed evidence that lifestyle or environmental factors meaningfully change that risk. Families with questions about what a result may mean for them can talk with a doctor or genetic counselor.
Inheritance of HPDL variants
HPDL-related conditions are inherited in an autosomal recessive pattern. This means a child usually inherits one HPDL gene variant from each parent, and parents who carry one variant are typically unaffected carriers. When both parents are carriers, each pregnancy has a 25% chance of the child inheriting both variants, a 50% chance of being a carrier, and a 25% chance of inheriting neither variant. In practical terms, how HPDL gene variants are inherited usually means the condition can appear unexpectedly in a family with no previous history.
What does my HPDL result mean for my family?
For families with an HPDL-related condition, it usually follows a recessive pattern, which means parents are often healthy carriers. Brothers and sisters may also be affected or may be carriers, and other close relatives could be carriers as well. The family impact depends on the exact result found in HPDL.
Genetic information
Genetic testing
How you find out about variants
To check for a variant in the HPDL gene, doctors use genetic testing for HPDL variants, usually using a blood or saliva sample. A lab reads the DNA code in the gene and looks for changes linked to disease, helping show whether a result supports a diagnosis, is unclear, or finds no relevant variant.
When should I consider getting a genetic test?
Genetic testing of the HPDL gene may be considered when someone has unexplained early-onset movement problems, muscle stiffness or weakness, developmental delay, or certain brain scan changes, especially if these run in the family. It can help confirm whether a rare inherited nerve and brain condition is the cause.
A genetic result is only one part of your health story
A genetic finding can provide useful insight, yet how much it reveals varies depending on the condition and the type of variant involved. Many factors, including lifestyle, environment, age, and medical history, influence how the body works over time. For some conditions, especially those shaped by many genes, genetic information provides context rather than certainty and is most useful when viewed alongside other parts of care. In other situations, a genetic result can offer a clear answer. In areas like medication response, it can also help put personal experiences into context.
Pharmacogenetics
How variants shape your response to medicine
Genetic variation can affect how people respond to medicines. Small differences in DNA can change how the body absorbs, breaks down, or moves a drug, so the same treatment may work better for one person than for another. This is common and can influence how much benefit someone gets from a medicine or how sensitive they are to side effects.
What is Pharmacogenetics?
Pharmacogenetics examines how genetic differences affect the way a person responds to medication. It focuses on links between genes and drugs to better explain why the same treatment can work differently from one person to another. For many medications, genes influence both how strongly a drug works and how the body handles it. This information can support more personalized and better informed treatment decisions. You can read more about this topic in the LearnHub.
Drugs influenced by the HPDL gene
When should I seek medical advice?
There is not yet a broadly confirmed role for this gene in guiding medication choice or predicting how well a medicine will work. If you have concerns about side effects, treatment response, or medicine interactions, talk with your doctor or pharmacist.