The TMEM38B gene helps control calcium movement inside cells, which supports collagen building and normal bone strength. If it does not work properly, the body may form weaker bone tissue, and people can have fragile bones, repeated fractures, short stature, or a curved spine. Differences in this gene can help explain why some people with osteogenesis imperfecta type XIV break bones more easily after everyday falls or bumps. The TMEM38B gene is mainly known in medical genetics rather than popular culture.
What is a gene?
A gene is a stretch of DNA that carries instructions your cells use to make molecules or regulate processes in the body. Some genes provide the directions for producing proteins, the parts of cells that do the work. Others mainly help decide when certain processes take place, where they occur, and how active they are. Taken together, genes affect how the body develops and functions, and they can influence how you respond to food, stress, or medications. You can learn more about this topic in the LearnHub.
Overview
TMEM38BGene function
What if the gene works
The TMEM38B gene helps control calcium movement inside cells. This supports collagen processing and healthy bone building, especially in cells that make and maintain bone.
Risk
What if the gene does not work
Variants in the TMEM38B gene can cause a form of osteogenesis imperfecta, leading to fragile bones, frequent fractures, and short stature. Milder to more severe variants may affect when problems begin and how strongly bone growth is affected.
Treatment
What does that mean for your treatment
No TMEM38B-specific treatment or drug choice is currently established. Care is based on the person’s bone symptoms and usual osteogenesis imperfecta management, not on a TMEM38B-directed medicine.
Conditions associated with TMEM38B
Gene function
What if the gene works
Your cells need tightly controlled calcium signals for many everyday jobs. Understanding what the TMEM38B gene does in the body helps explain how cells move calcium in a steady way. The TMEM38B gene helps build a tiny channel in the endoplasmic reticulum, a storage space inside cells that holds calcium.
The TMEM38B gene helps create a small channel that lets positive ions move across an internal cell membrane. This movement supports the normal flow of calcium from the cell’s storage space.
When calcium leaves its storage area, electrical charge inside that compartment also shifts. The TMEM38B gene helps balance that charge, so calcium release can continue in a controlled way.
By supporting calcium movement, this gene helps cells send and respond to signals. These calcium signals guide routine activities such as movement, secretion, and other coordinated cell tasks.
What is a variant?
A genetic variant is a minor change in the DNA sequence of a gene. These changes are common and help shape normal differences among people, including appearance, metabolism, and how the body responds to environmental influences. Many variants do not have any noticeable effect and are simply part of natural genetic variation. In some cases, though, a variant changes how a gene functions more substantially and may contribute to or cause a genetic condition.
Genetic variants
What if the gene does not work
Variants in the TMEM38B gene can reduce or remove the TRIC-B protein (a channel that helps move calcium inside cells), which disrupts calcium balance and collagen handling in bone-forming cells. This explains how TMEM38B gene variants affect protein function across a spectrum: milder variants may leave some channel activity, while more severe variants often cause little to none. In people with TMEM38B-related osteogenesis imperfecta, greater functional loss can be linked to earlier or more marked bone fragility.
How variants are linked to conditions
Pathogenic variants in the TMEM38B gene cause autosomal recessive osteogenesis imperfecta type 14, a form of brittle bone disease. People with this condition often have repeated fractures, low bone density, and short stature, and some also develop spine curvature. Finding disease-causing variants in both copies of the TMEM38B gene can confirm a TMEM38B gene variant linked to osteogenesis imperfecta.
A variant is not necessarily a diagnosis
Genetic variants are a common and normal part of human biology. Most do not have a direct effect on health and simply contribute to natural human diversity. For many genes, having a variant associated with a condition indicates a possible link rather than a definite diagnosis, especially when several genes and environmental factors are involved. In some cases, though, a single well-characterized variant in a specific gene is enough to confirm a diagnosis.
Are there things that can increase or change my risk?
For TMEM38B, risk is mainly shaped by inheritance rather than lifestyle. A child’s chance of having a TMEM38B-related bone condition is higher when both parents carry a nonworking copy of the gene, and this can be more likely in families with shared ancestry or known family history.
Inheritance of TMEM38B variants
TMEM38B-related conditions are inherited in an autosomal recessive pattern. In practical terms, TMEM38B gene inheritance usually means a child is affected only when they receive one disease-causing variant from each parent. When both parents are carriers, each pregnancy has a 25% chance of being affected, a 50% chance of resulting in a carrier child, and a 25% chance of resulting in a child without the familial variants. Because the TMEM38B gene is on chromosome 9, sons and daughters inherit it in the same way.
What does my TMEM38B result mean for my family?
For families, a TMEM38B result usually means close relatives could be carriers of the same gene change, even if they do not have symptoms. Brothers and sisters may also be affected or be carriers, depending on which gene changes they inherited. Family members often think about testing mainly to clarify carrier status and chances for future children.
Genetic information
Genetic testing
How you find out about variants
TMEM38B genetic testing for brittle bone disease usually uses a blood or saliva sample. A lab reads the TMEM38B gene as part of a bone fragility panel, exome, or genome test and compares it with the usual DNA sequence to look for variants that may explain symptoms or clarify family carrier status.
When should I consider getting a genetic test?
Testing for the TMEM38B gene may be considered when someone has very fragile bones, repeated fractures from little or no injury, or a family history of an inherited brittle bone condition. It can also help if a close relative is known to carry a TMEM38B change.
A genetic result is only one part of your health story
Genetic results can be informative, but what they can tell you varies based on the condition and the kind of variant involved. Over time, many factors, including lifestyle, environment, age, and medical history, also shape how the body functions. For some conditions, especially those influenced by many genes, genetic information offers context rather than certainty and is best considered alongside other parts of care. In other situations, a genetic result can provide a clear answer. In areas like medication response, genetic results may also help put individual 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, transports, or responds to a drug, so the same treatment may work well for one person but less well for another. This is a common part of normal human variation and can influence both how much benefit a medicine provides and how sensitive someone may be to side effects.
What is Pharmacogenetics?
Pharmacogenetics examines how genetic differences can shape a person’s response to medicines. It studies the relationship between genes and drugs to help explain why the same treatment may work differently from one person to another. For many medications, genes can affect how strongly a drug works or how the body handles it. This information can support more informed, individualized treatment decisions. To explore this topic further, you can learn more in the LearnHub.
Drugs influenced by the TMEM38B gene
When should I seek medical advice?
There is not yet a broadly confirmed role for this gene in guiding medication choices. Questions about medicines, side effects, or changes in how you feel are best discussed with your doctor or pharmacist.
History
TMEM38B entered medical genetics in the 2010s, when researchers studying families with brittle bones identified harmful variants in the TMEM38B gene as a cause of a recessive form of osteogenesis imperfecta. Initially understood through clinical features and X ray findings, the condition was later tied to TMEM38B through modern DNA sequencing. From these first observations, research expanded steadily, helping clinicians recognize that TMEM38B related osteogenesis imperfecta can appear in different populations and with varying severity. This discovery added an important chapter to the broader history of inherited bone conditions and improved the accuracy of genetic diagnosis for affected families.