| Krabbe disease is inherited in an autosomal | | | | not make enough of a substance called |
| recessive manner. If both parents are carriers, | | | | galactocerebroside beta-galactosidase |
| each child has a 25% chance of being affected, a | | | | (galactosylceramidase). The body needs this |
| 50% chance of being an asymptomatic carrier, | | | | substance to make myelin, the material that |
| and a 25% chance of being unaffected and not a | | | | surrounds and protects nerve fibers. Without it, |
| carrier. Each healthy sib of a proband has a 2/3 | | | | myelin breaks down, brain cells die, and nerves in |
| chance of being a carrier. For genetic counseling | | | | the brain and other body areas do not work |
| purposes, a carrier frequency of one in 150 may | | | | properly. Symptoms The symptoms of Krabbe |
| be used for the general population. Prenatal | | | | disease usually begin before the age of 1 year |
| diagnosis is possible either by measurement of | | | | (the infantile form). Initial signs and symptoms |
| GALC enzyme activity or by molecular genetic | | | | typically include irritability, muscle weakness, |
| testing if both disease-causing alleles in an | | | | feeding difficulties, episodes of fever without any |
| affected family member are known. Causes | | | | sign of infection, stiff posture, and slowed mental |
| Krabbe disease is caused by mutations in the | | | | and physical development. As the disease |
| GALC gene, which causes a deficiency of an | | | | progresses, muscles continue to weaken, |
| enzyme called galactosylceramidase. The buildup | | | | affecting the infant's ability to move, chew, |
| of unmetabolized lipids affects the growth of the | | | | swallow, and breathe. Affected infants also |
| nerve's protective myelin sheath (the covering | | | | experience vision loss and seizures. The cause of |
| that insulates many nerves) and causes severe | | | | Krabbe disease is a deficiency in an enzyme called |
| degeneration of mental and motor skills. As part | | | | galactocerebrosidase (GALC), which is essential |
| of a group of disorders known as | | | | for the maintenance of myelin - a fatty substance |
| leukodystrophies, Krabbe disease results from the | | | | that insulates your nerve fibers. A child needs to |
| imperfect growth and development of myelin. | | | | inherit an abnormal gene from each parent to |
| Persons with this gene defect do not make | | | | trigger the disorder. Passing on the genes occurs |
| enough of a substance called galactocerebroside | | | | in an inheritance pattern called autosomal |
| beta-galactosidase (galactosylceramidase). The | | | | recessive. Specifically, Krabbe disease has been |
| body needs this substance to make myelin, the | | | | linked to a defect in chromosome 14. Treatment |
| material that surrounds and protects nerve fibers. | | | | There is no cure for Krabbé disease. Results |
| Without it, myelin breaks down, brain cells die, and | | | | of a very small clinical trial of patients with infantile |
| nerves in the brain and other body areas do not | | | | Krabbé disease found that children who |
| work properly. The cause of Krabbe disease is a | | | | received umbilical cord blood stem cells from |
| deficiency in an enzyme called | | | | unrelated donors prior to symptom onset |
| galactocerebrosidase (GALC), which is essential | | | | developed with little neurological impairment. |
| for the maintenance of myelin - a fatty substance | | | | Results also showed that disease progression |
| that insulates your nerve fibers. A child needs to | | | | stabilized faster in patients who receive cord blood |
| inherit an abnormal gene from each parent to | | | | compared to those who receive adult bone |
| trigger the disorder. Passing on the genes occurs | | | | marrow. Bone marrow transplantation has been |
| in an inheritance pattern called autosomal | | | | shown to benefit mild cases early in the course of |
| recessive. A defect in the GALC gene causes | | | | the disease. Generally, treatment for the disorder |
| Krabbe disease. Persons with this gene defect do | | | | is symptomatic and supportive. |