Bloom Syndrome: Causes, Symptoms, and Treatment
Medically reviewed by Achuta Uppu, MD, Internal Medicine. Last reviewed: October 23, 2026.
What kind of doctor treats Bloom Syndrome?
A medical geneticist (a doctor who treats inherited conditions) usually leads care for Bloom syndrome, together with a primary care doctor and cancer specialists for screening. A direct primary care or concierge doctor can be a first stop for an evaluation and can refer you to a specialist when needed.
What is Bloom syndrome?
Bloom syndrome is a rare inherited disorder. It causes short stature, a skin rash after sun exposure, and a greatly increased risk of cancer. It happens when both copies of a gene called BLM have changes. These changes are also called mutations. The BLM gene tells the body how to make a protein. This protein helps keep DNA stable and repair damage. Without it, DNA becomes unstable, which leads to the health problems of this condition. Only a few hundred cases have been described in medical writing. About one-third are in people of Central and Eastern European (Ashkenazi) Jewish background.
Symptoms
People with it are usually smaller than 97 percent of the population in height and weight from birth. They rarely grow taller than 5 feet as adults. Common signs include:
- A red, butterfly-shaped rash on the nose and cheeks after sun exposure. It can also appear on the hands and forearms.
- Skin that is very sensitive to sunlight.
- A long, narrow face, a small lower jaw, and a prominent nose and ears.
- A high-pitched voice.
- Learning disabilities in some people.
Many people have mild immune system problems. These lead to repeated ear and lung infections in infancy. Other risks include diabetes and COPD, a serious lung disease. Cancer is the biggest risk. Cancers of any type can happen. They start earlier in life than in other people. Often more than one type appears.
Causes and who gets it
Bloom syndrome is inherited in an autosomal recessive pattern. This means a child must get a changed BLM gene from both parents. Parents who carry only one changed copy usually have no symptoms. The changed gene allows breaks and exchanges in chromosomes that damage cells. Cells also become less able to repair sun damage. That causes the sun sensitivity. It occurs in many ethnic groups, but it is more common in people of Ashkenazi Jewish heritage.
How doctors diagnose it
Doctors look at the telltale features: small size, the sun-sensitive rash, and the face shape. To confirm it, they use molecular testing. This is a lab test that looks for changes in the BLM gene.
Treatment
There is no cure. Treatment works on symptoms and on catching cancer early:
- Sun protection: stay out of the sun. Cover skin with clothes, a wide-brimmed hat, and sunscreen. See a skin doctor (dermatologist) once a year.
- Cancer screening: a colonoscopy, a camera exam of the large bowel, every 1 to 2 years from age 10 to 12. A breast MRI each year for women over 18. A whole-body MRI every 1 to 2 years from about age 12 or 13.
- Yearly checks for diabetes and thyroid problems from age 10.
- Standard care for infections, feeding problems, and reflux.
Growth hormone therapy has not consistently increased growth in these children. Doctors use it with caution. For infertility, a fertility specialist can discuss options, such as assisted reproductive technology (lab methods to help conception). Genetic counseling is recommended for affected people and their families.
When to see a doctor
Children who grow much more slowly than expected should be checked by a doctor. So should children who get a red face rash after sun exposure. Unintentional weight loss, unusual bleeding, enlarged lymph nodes, or drenching night sweats need a doctor right away. Cancer risk is high, and cancers tend to start earlier in life.
How a direct primary care or concierge doctor fits in
A direct primary care doctor charges a flat monthly fee instead of billing insurance, while a concierge doctor usually charges more and often works alongside insurance. Either one can track the regular screening schedule. They can also set up visits with the geneticist and cancer specialists.
Common questions
How is Bloom syndrome inherited?
It is inherited in an autosomal recessive pattern, which means a child must receive a changed BLM gene from both parents. Parents who carry one changed copy usually have no symptoms.
Why do people with Bloom syndrome get cancer more often?
The changed BLM gene cannot keep DNA stable or repair damage well. Cells then build up genetic changes that let them grow without control, which leads to cancer. Cancers also start earlier in life.
Can people with Bloom syndrome have children?
It depends. Men with Bloom syndrome usually do not make sperm and cannot father children. Women have reduced fertility and earlier menopause, but some have had healthy babies. A fertility specialist can discuss options.
Is Bloom syndrome more common in any group?
Yes. About one-third of described cases are in people of Central and Eastern European (Ashkenazi) Jewish background, but it occurs in many ethnic groups.
Sources
- MedlinePlus Genetics - Bloom syndrome
- National Organization for Rare Disorders (NORD) - Bloom Syndrome
Medical Disclaimer
This content is for general educational and informational purposes only and is not medical advice. It is not a substitute for professional medical advice, diagnosis, or treatment, and reading it does not create a doctor-patient relationship. Always seek the advice of your physician or another qualified health provider with any questions about a medical condition, and never disregard or delay seeking professional advice because of something you read here. If you think you may have a medical emergency, call 911 (or your local emergency number) immediately.
