Properdin Deficiency: Causes, Symptoms, and Treatment
Medically reviewed by Harsha Moole, MD, Internal Medicine. Last reviewed: October 2, 2026.
What kind of doctor treats Properdin Deficiency?
A primary care doctor often notices the pattern of infections first and may refer the person to an immunologist, a specialist in immune system problems. An infectious disease doctor may also be involved. Many people see both a primary care doctor and a specialist over time.
What it is
Properdin deficiency is a rare inherited problem with the immune system. Properdin is a protein that helps the complement system, a group of blood proteins that attack germs. Without working properdin, this attack system does not turn on properly, making it harder to fight certain bacterial infections.
Symptoms
The main sign is getting serious infections again and again, often caused by Neisseria bacteria. These germs cause meningitis, an infection of the lining around the brain and spinal cord, and gonorrhea. Infection may bring fever, chills, headache, stiff neck, or extreme tiredness.
Causes and who gets it
Properdin deficiency is passed down through genes and is linked to a gene on the X chromosome. Because of this, it mostly affects boys and men. Women can carry the changed gene without being sick, or with only mild problems.
How doctors diagnose it
A doctor will ask about health history and family infections. Blood tests can measure how well the complement system works and check properdin levels. Genetic testing can confirm the diagnosis, and family members may be offered testing too.
Treatment
There is no cure, but infections can be treated with antibiotics. Vaccines help protect against the bacteria a person is most likely to catch. The plan is adjusted based on how often and how severely infections happen.
When to see a doctor
Anyone with repeated serious infections should talk to a doctor. Signs of meningitis, such as stiff neck, bad headache, high fever, or confusion, need emergency care right away. Relatives of someone diagnosed may want to ask about testing.
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 can spend extra time ordering tests, treating simple infections, and coordinating vaccines. When infections point to an immune problem, they refer the patient to a specialist and can manage routine follow-up afterward.
Common questions
Is properdin deficiency curable?
No, there is no cure, because the condition comes from a changed gene. The infections linked to it can usually be treated with antibiotics, and vaccines can lower the risk of getting sick.
Can women have properdin deficiency?
It is possible but uncommon. Women who carry one changed copy of the gene usually do not get sick, though a few have mild immune problems.
Should family members get tested?
Many doctors suggest it, since the condition runs in families. A genetic counselor can explain what testing might show for each relative.
Sources
- NIH Genetic and Rare Diseases Information Center - Properdin deficiency, X-linked
- MedlinePlus - Immune System and Disorders
- MedlinePlus - Meningitis
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.
