People carry the PARL gene to help the tiny energy units inside cells, called mitochondria, stay healthy and work efficiently. This gene helps your body manage key mitochondrial proteins and support steady energy production. If the gene does not work well, cells may struggle to make enough energy, especially in the brain, muscles, and heart. In some people, harmful variants in the PARL gene are linked to mitochondrial disease, developmental delay, weakness, seizures, or movement problems.
What is a gene?
Genes are stretches of DNA that give your cells instructions for making molecules or regulating processes in the body. Some genes carry the code for proteins, the parts of cells that do much of the work. Other genes are mainly involved in controlling when certain processes happen, where they happen, and how strongly they occur. Together, genes affect how the body develops and works, and they can shape how you respond to food, stress, or medications. More on this topic is available in the LearnHub.
Overview
PARLGene function
What if the gene works
The PARL gene helps mitochondria, the parts of cells that make energy, work properly. It helps cells maintain healthy mitochondria and supports energy balance and cell survival.
Risk
What if the gene does not work
More disruptive PARL variants can impair mitochondrial quality control and are linked to a rare mitochondrial encephalopathy, often beginning in infancy. Depending on the variant, people may have developmental delay, low muscle tone, seizures, and sometimes heart involvement.
Treatment
What does that mean for your treatment
No PARL-specific treatment or management approach is currently established. Care is based on the person’s symptoms and the underlying condition rather than on a pathogenic variant in the PARL gene itself. The PARL gene is being studied as part of mitochondrial quality control, including research on neurodegeneration and rare mitochondrial disease, but this has not yet changed routine drug choices.
Gene function
What if the gene works
Your cells depend on healthy mitochondria, the parts of cells that make energy for everyday tasks. The PARL gene helps manage their upkeep by processing selected proteins inside mitochondria. This is part of how the PARL gene supports mitochondria and steady cell function.
Inside mitochondria, its protein acts like a careful cutter that trims selected proteins into working forms. This helps important signals inside mitochondria stay well timed.
By processing key mitochondrial proteins, the PARL gene helps these energy making structures work smoothly. This supports a steady energy supply for everyday cell tasks.
The PARL gene helps control the signals cells use to check mitochondrial health. It helps decide whether a mitochondrion is kept in service or sent for normal cellular cleanup.
Its protein also shapes signals linked to normal cell stress and survival. This helps mitochondria adjust to routine strain in a controlled way.
What is a variant?
A genetic variant is a minor difference in the DNA sequence of a gene. These differences are common and help account for normal human diversity, including differences in appearance, metabolism, or how the body responds to environmental influences. Many variants do not cause any noticeable effect and simply represent natural genetic variation. At times, though, a variant can more substantially change how a gene functions and may contribute to or cause a genetic condition.
Genetic variants
What if the gene does not work
To understand how PARL gene variants affect protein function, it helps to know that different DNA changes can weaken this protein to different degrees. Variants in the PARL gene may alter the protein’s shape, make it less stable, reduce its protease activity (its ability to cut other proteins), or disrupt how it sits in the inner membrane of mitochondria, the cell’s energy centers. Milder variants may leave some activity, while more severe variants can lead to little or no normal PARL function.
How variants are linked to conditions
Pathogenic variants in the PARL gene are linked mainly to a rare inherited mitochondrial condition that can present as Leigh syndrome or a Leigh-like syndrome, often beginning in infancy or early childhood. In this setting, having two disease-causing PARL variants can confirm the diagnosis. Some studies have explored links between the PARL gene and Parkinson disease risk, but those findings are not considered broadly established.
A variant is not necessarily a diagnosis
Genetic variants are a normal feature of human biology and are common throughout the general population. Most do not have a direct impact on health and instead reflect natural human diversity. For many genes, carrying a variant associated with a condition indicates a possible link rather than a definite diagnosis, particularly when several genes and environmental factors contribute. In some situations, though, a single well-characterized variant in a particular gene can be enough to confirm a diagnosis.
Are there things that can increase or change my risk?
There is not yet broadly confirmed evidence on specific factors that increase or reduce health risk related to the PARL gene. If a PARL change is found on testing, personal risk often depends on the exact variant and the rest of your health and family history.
Inheritance of PARL variants
For families asking about PARL gene inheritance, the well-established disease pattern is autosomal recessive. This means a child usually inherits one PARL gene variant from each parent, and the parents are often healthy carriers. When both parents carry a disease-causing variant, each pregnancy has a 25% chance of an affected child, a 50% chance of a carrier child, and a 25% chance of a child with no familial variant. Because the PARL gene is on an autosome, this pattern is the same for boys and girls.
What does my PARL result mean for my family?
There is not yet a broadly confirmed family inheritance pattern for PARL that is used in routine care in the same way as some better-known disease genes. Research has linked certain PARL changes to rare inherited conditions in some families, but what a result means for relatives depends a lot on the exact change and the health findings in that family. A doctor or genetic counselor can explain what a specific PARL result may mean for parents, children, brothers, sisters, and future pregnancies.
Genetic information
Genetic testing
How you find out about variants
Testing for changes in the PARL gene usually uses a blood or saliva sample. PARL genetic testing reads the gene’s DNA sequence to look for variants and may be done on its own or as part of a larger panel or exome test. Results can confirm a variant, show none was found, or identify a change whose meaning is not yet clear.
When should I consider getting a genetic test?
PARL testing may be considered when a baby or child has signs of a rare inherited condition that affects how cells make energy, especially if there is developmental loss, muscle weakness, seizures, or similar illness in the family. It is usually looked at as part of a broader genetic test rather than on its own.
A genetic result is only one part of your health story
Genetic results can provide meaningful insight, but how much they reveal varies by the condition and the type of variant involved. Many factors, including lifestyle, environment, age, and medical history, also shape how the body works over time. For some conditions, especially those influenced by many genes, genetic information provides context rather than certainty and is best understood as part of the broader picture of care. In other situations, a genetic result may offer a clear answer. In areas such as medication response, genetic results can also help put individual experiences into context.
Pharmacogenetics
How variants shape your response to medicine
Genetic variation can affect how people respond to medicines. Some people break down a drug more slowly or more quickly, while others may have small differences in the drug target inside the body. This helps explain why the same treatment can work well for one person, seem weaker for another, or cause more side effects in someone else. These differences are common and are one reason medication response can vary from person to person.
What is Pharmacogenetics?
Pharmacogenetics is the area of study that focuses on how genetic differences affect response to medications. It examines patterns linking genes and drugs to help explain why treatment can work differently from one person to another. For many medicines, genes influence both how strongly a drug works and how the body handles it. This information can support treatment decisions that are more informed and more individualized. To explore this subject in greater detail, you can learn more in the LearnHub.
Drugs influenced by the PARL gene
When should I seek medical advice?
There is not yet a broadly confirmed role for this gene in guiding medication response, so general health or medication concerns are best discussed with your doctor.
History
PARL entered the scientific literature in the early 2000s, when researchers identified it as a human relative of rhomboid proteins and named it presenilins associated rhomboid like. It first drew attention because of its connection to presenilin proteins, which were already under close study in brain disease research. Building on this early work, scientists later placed PARL in mitochondria, the parts of cells that handle energy, which shifted interest toward broader questions about cell stress and survival. Interest widened further when rare variants in the PARL gene were reported in some families with inherited conditions and when laboratory studies linked it to pathways involved in Parkinson disease. Over time, descriptions became more precise as genetics and cell biology clarified where the PARL gene fits in human disease research.