Are Heart Murmurs Genetic? Understanding Causes, Risks, and Inheritance

Explore how genetics influence heart murmurs—from innocent childhood sounds to inherited heart conditions—and know the warning signs.

By Medha deb

Created on Sep 27, 2025

Explore how genetics influence heart murmurs—from innocent childhood sounds to inherited heart conditions—and know the warning signs.

Heart murmurs are audible sounds made by turbulent blood flow in the heart. While often harmless, they can signal underlying heart disease, some of which may have a genetic basis. Whether you have a family history of heart murmurs or simply want to understand the potential risks, this comprehensive guide will explore how genetics can influence heart murmurs, what causes them, and what signs to watch for.

What is a Heart Murmur?

A heart murmur is an extra or unusual sound heard during a heartbeat, detected using a stethoscope. These sounds resemble a whooshing or swishing noise, caused by blood moving through the heart’s valves and chambers.

Innocent (or functional) heart murmurs: Harmless murmurs not caused by heart problems. Common in children and often transient, they don’t require medical treatment. Factors like fever, physical activity, or pregnancy can provoke them.
Abnormal heart murmurs: These may indicate an underlying structural issue in the heart, such as a congenital heart defect, valve disease, or other medical conditions. Abnormal murmurs often require further evaluation and possibly treatment.

Heart murmurs are most frequently diagnosed in children, with studies estimating that up to 80% of children will experience a murmur at some point. However, fewer than 1% of child murmurs reviewed by a cardiologist are due to congenital heart disease. Most resolve without intervention.¹

How Are Genetics Involved in Heart Murmurs?

A heart murmur itself is a sign—not a diagnosis—but the underlying condition causing the murmur may be genetic. Genetic heart conditions are caused by mutations that affect the heart’s structure or function, and they can be inherited from one or both parents.

Family history: Having close relatives with congenital heart diseases or valve disorders increases your risk of developing similar conditions, including those that cause murmurs.
A 2021 pediatric study found that not having a family history of congenital heart disease made it less likely a child’s murmur would be due to a congenital defect, highlighting the role of genetics in risk.¹
Abnormal murmurs caused by inherited diseases (such as certain valve defects) may be passed down through generations.

It’s important to recognize that while genetics is a significant factor, not all murmurs—especially innocent ones—have a hereditary basis.

What Causes Heart Murmurs?

The causes of heart murmurs fall into two categories: those resulting in innocent murmurs and those producing abnormal murmurs. The underlying reasons can differ based on age and overall health.

Common Causes of Innocent Heart Murmurs

Childhood growth spurts
Fever
Physical exercise
Anemia (low red blood cell count)
Pregnancy
Thyroid disease (such as hyperthyroidism)

A particular type of innocent murmur, known as Still’s murmur, often appears in children between ages 3 and adolescence and usually resolves with age.¹

Common Causes of Abnormal Heart Murmurs

Congenital heart disease: Structural heart defects present from birth, such as ventricular septal defects or bicuspid aortic valve
Heart valve disorders: Such as mitral valve prolapse or stenosis
Endocarditis: Infection and inflammation of the heart’s inner lining
Carcinoid syndrome: Rare tumors that affect the heart
Degenerative changes: Age-related changes in heart valves causing leakage or narrowing

Genetic Conditions Connected to Heart Murmurs

Certain inherited heart conditions are more likely to produce murmurs due to structural abnormalities they create. The following table shows major conditions with a genetic link:

Condition	Genetic Connection	Risk for Murmurs
Mitral Valve Prolapse	35-50% hereditary component ¹	High—causes abnormal valve closure
Bicuspid Aortic Valve	Often runs in families ¹	High—may alter blood flow and cause murmur
Ventricular Septal Defect (VSD)	Genetic factors involved ¹	High—hole in heart wall changes blood flow
Hypertrophic Cardiomyopathy (HCM)	Autosomal dominant inheritance ⁴	High—thickened heart muscle causes turbulence
Cardiac Amyloidosis or Tumors	Can be hereditary ¹	Presents in some families with rare disorders

Not all structural heart issues are inherited, but these specific conditions often have a genetic basis. Discuss your family medical history with your doctor to understand your risk.

Signs to Look for If You’re Genetically at Risk

When there’s a family history of heart murmurs or related structural heart disease, it’s vital to recognize warning signs that may indicate a problem requiring medical evaluation. While innocent murmurs don’t involve other symptoms, abnormal murmurs often do, such as:

Shortness of breath
Chest pain or discomfort
Rapid heartbeat or palpitations
Fainting or dizziness
Swelling of legs, ankles, or abdomen
Excessive fatigue (unusual tiredness)
Poor feeding or growth in infants and young children

Some inherited conditions like hypertrophic cardiomyopathy (HCM) can cause sudden symptoms and may even lead to life-threatening complications without prior warning. If you or a family member experiences these symptoms—especially if you have a known genetic risk—seek prompt medical evaluation.

Risk Factors that Increase the Likelihood of Heart Murmurs

Genetic risk is not the only factor. The likelihood of having a heart murmur increases due to:

Family history of heart murmurs or congenital heart defects
Uncontrolled diabetes in the mother during pregnancy
Infections during pregnancy, such as German measles (rubella)
Some medications, drugs, or alcohol during pregnancy

Other medical conditions—many of which may not be genetic—also heighten risk, including:

Carcinoid syndrome (rare tumor)
Endocarditis
Anemia
Autoimmune disorders (e.g., lupus, rheumatoid arthritis)
Pulmonary hypertension (high blood pressure in the lungs)
Overactive thyroid
Previous rheumatic fever

Diagnosis and Evaluation

When a murmur is detected, physicians perform a thorough evaluation to determine:

Whether the murmur is innocent or abnormal
If the murmur is associated with a genetic or structural heart condition
Whether further investigations, such as an echocardiogram (heart ultrasound), ECG, or genetic counseling, are needed

Family and patient history is a critical component—be prepared to share any information about heart disease or sudden cardiac events among relatives.

When Is a Heart Murmur Harmless?

Most murmurs in children and young adults are innocent and require no treatment. Features that suggest a murmur is benign include:

No associated symptoms like fainting, chest pain, or shortness of breath
No family history of significant heart disease or sudden cardiac events
Normal physical development and activity levels

Still, any newly identified murmur—especially with symptoms or a positive family history—should be assessed by a healthcare provider.

Treatment and Management Options

Innocent murmur: No treatment required, only reassurance and regular monitoring.

Abnormal murmur: Treatment depends on the underlying cause, which may include:

Medications (for infection, blood pressure, or heart failure)
Heart valve repair or replacement surgery
Management of associated conditions (e.g., treating anemia or thyroid disease)

People identified to have a genetic heart condition may be referred for genetic testing and counseling to determine risks for family members.

Prevention and Family Planning Considerations

If you have a known genetic heart condition or strong family history, discuss with your healthcare team:

Preconception and prenatal genetic counseling
Screening for heart conditions in children or relatives
Adopting a healthy lifestyle to reduce other risk factors (control blood pressure, avoid smoking, manage diabetes, etc.)

Frequently Asked Questions (FAQs)

Q: Are heart murmurs always inherited?

No. While certain murmurs are linked to genetic heart conditions, many murmurs—especially innocent ones in children—are not inherited and may disappear over time.

Q: What heart conditions linked to murmurs are most likely to be genetic?

Conditions such as mitral valve prolapse, bicuspid aortic valve, ventricular septal defect, and hypertrophic cardiomyopathy often have a hereditary component.

Q: What should I do if my child has a heart murmur and there is a family history?

Consult a pediatric cardiologist, who may recommend further tests (like an echocardiogram) to rule out significant inherited heart defects. Keep a record of your family’s heart history and share it with your provider.

Q: Can adults develop genetic heart murmurs later in life?

Most genetically linked heart murmurs present in childhood, but some conditions, such as degenerative valve disease (which may also have familial tendencies), can develop or worsen later in adulthood.

Q: Is it safe to exercise with a heart murmur?

People with innocent murmurs can usually participate in normal physical activity. If an abnormal murmur is present, your doctor will advise on safe levels of activity based on the underlying heart condition.

Takeaway

While genetics can play a significant role in certain heart murmurs, the majority are harmless and non-hereditary. If you or your child are diagnosed with a murmur—especially with a family history of heart or valve problems—further evaluation is important. Early detection and management improve outcomes for those with inherited heart conditions.

References

Author

medha deb

Medha Deb is an editor with a master's degree in Applied Linguistics from the University of Hyderabad. She believes that her qualification has helped her develop a deep understanding of language and its application in various contexts.

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