Infantile Krabbe disease

In U.S. states that screen for it, a baby can be found through the newborn blood spot test. The lab first measures the GALC enzyme. If it is low, a second test on the same blood spot measures psychosine, the toxic substance that builds up. A high psychosine level points to the infantile form. U.S. guidelines aim to have these results by the end of the baby’s first week.

A specialist team then confirms the diagnosis. This usually means an enzyme test on white blood cells, a psychosine level and a test of the GALC gene. In the guidelines’ model timeline, the baby is referred to a transplant center within the first week of life. There, the baby may have a brain MRI, a spinal tap to check protein in the spinal fluid, nerve tests, hearing and vision tests, an EEG (a test of brain waves) and tissue typing (HLA typing).

Babies with a family history of Krabbe disease can be tested right after birth, or before birth when the family’s gene changes are known. Without screening or a family history, the diagnosis is usually made only after clear symptoms appear. By then it is usually too late for a transplant to work well.

A donor stem cell transplant is the only treatment available today that changes the course of infantile Krabbe disease. Cells that grow from the donor’s stem cells settle in the body, including the brain, and make the missing enzyme. Expert guidance aims to start transplant within the first 4 weeks of life.

That timeline is very tight. After an abnormal screen, the baby must be referred, the diagnosis confirmed, a donor chosen and about 9 days of chemotherapy given before the transplant. US consensus guidelines ask for referral to a center experienced in these transplants no later than the third week of life.

Results after early transplant are far better than without treatment, but they vary. In one US program’s study, 18 babies were transplanted in their first 7 weeks and followed for 4 to 15 years. Thirteen were alive. Five had died, three of them from complications of the transplant.

Most survivors kept learning, often more slowly than other children. Three could walk on their own and seven walked with help from devices. Twelve wore braces (orthotics).

In the 2022 report of six babies found by screening outside New York, all were alive 2½ to nearly 5 years later. They were gaining skills slowly, and movement was most affected.

Transplant does not undo damage that has already happened. Nerve damage in the arms and legs often keeps getting worse after transplant. Babies found only after symptoms start are usually not eligible for transplant. In the 2022 report, every family was also offered comfort-focused (palliative) care without transplant as another path.

No gene therapy for Krabbe disease is approved in the United States. A gene therapy given after transplant is being tested in an early (phase 1/2) clinical trial. As of September 2026, that trial was no longer taking new patients.

When a transplant from a donor is planned, the team usually tests brothers and sisters first. Each full sibling has about a one in four chance of being a full match.

Most patients do not have a matched relative. In the words of NMDP, the U.S. registry, “75% of patients don’t have a fully matched donor in their own family.” The team then searches registries of volunteer donors around the world and banks of donated cord blood. In some transplants, a half-matched parent, child or sibling can also be the donor.

Matching depends on inherited tissue markers called HLA, so a patient is most likely to match someone who shares their ancestry. Every person who joins makes the search a little more likely to succeed, especially for patients from groups that are underrepresented on registries.

Without treatment, infantile Krabbe disease is usually fatal in early childhood. The biggest factor in outlook is the timing of transplant. How far the disease has moved by the time of treatment also matters.

With early transplant, many children live for years and keep learning, often more slowly than other children. Movement is usually the most affected, and many children need braces or walking aids. Surviving is not the same as keeping normal nerve function, and experts say transplant does not cure Krabbe disease. The transplant itself also carries a real risk of early death.

Families face this decision soon after diagnosis, often while their baby still looks well. Care teams talk through both paths, transplant or comfort-focused (palliative) care, so families can choose what fits their child.