Global Gene Therapy Clinical Trial for

Infantile Malignant Osteopetrosis

Infantile Malignant Osteopetrosis, or IMO, is a rare genetic disease that is characterized by increased bone density¹.


It occurs when cells, called osteoclasts, that are responsible for bone growth and repair do not work properly¹.

It is caused by inheriting a faulty gene2.

lightning bolt

1 in 250,000 children around the world have it¹.

Parents & caregivers may notice….

Crying & fussy baby

Constant runny nose

Trouble feeding

Smaller than other babies

Photo of a baby

During the check-up, the doctor may find:

  • Eyes wide apart
  • Thick gums
  • Pale skin color
X-Ray of hand

The doctor might see the following in a blood test and x-ray:

  • Anemia in blood test
  • Thick bones on x-ray
Double Helix

The doctor may do a genetic test and find the following to confirm diagnosis of IMO:

  • a problem in a gene called TCIRG1

What can parents & caregivers do about IMO?

Know that there is no cure and to watch out for worsening of vision, hearing, and learning difficulties

Doctor icon

Speak to the child’s doctor about options for treatment

The doctor may talk about whether a gene therapy clinical trial would be a possible treatment option

Who is eligible to participate in the IMO gene therapy clinical trial?

Babies at least 1 month old or more

A confirmed diagnosis of IMO with documented TCIRG1 mutation

No HLA-matched sibling donor available

What does participation in the IMO gene therapy clinical trial involve?

There are 3 key steps that take place during the trial:

Patient Laying In Bed
  • Blood stem cells are taken from the patient
  • This takes ~ 5 days in the hospital
  • Therapeutic gene is inserted into the patient’s own cells  at a lab
  • This takes 1-2 months.  Patients will come back to hospital once this process is complete.
  • Patients will receive a drug called busulfan to help get body ready to receive the gene therapy (~ 4 days)
  • Finally, patients receive gene therapy product and will be kept in the hospital for ~ 1 month to closely monitor disease & treatment effects

Where will the IMO gene therapy clinical trial be taking place?

University of California, Los Angeles (UCLA) in Los Angeles, California, USA

Learn more about US site

How much will it cost to participate in the trial?

Financial support, including travel arrangements and housing accommodations for patients and a family member, both for the treatment and follow-up visits, will be provided.

This will also include assistance with passports, medical visas and translation services for patients and families if these are needed.

Where can I get more information about the IMO gene therapy clinical trial?



  1. Stark Z, Savarirayan R. Osteopetrosis. Orphanet J Rare Dis. 2009;4:5. Published 2009 Feb 20. doi:10.1186/1750-1172-4-5
  2. Villa, A., Guerrini, M.M., Cassani, B. et al. Infantile Malignant, Autosomal Recessive Osteopetrosis: The Rich and The Poor. Calcif Tissue Int 84, 1 (2009).
  3. Essabar L, Meskini T, Ettair S, Erreimi N, Mouane N. Malignant infantile osteopetrosis: case report with review of literature. Pan Afr Med J. 2014;17:63. Published 2014 Jan 27. doi:10.11604/pamj.2014.17.63.3759