The gene mutation associated with Krabbe disease only causes the disease if two mutated copies of the gene are inherited. A disease resulting from two mutated copies is called an autosomal recessive disorder.
If each parent has one mutated copy of the gene, the risk for a child would be as follows:
- A 25 percent chance of inheriting two mutated copies, which would result in the disease
- A 50 percent chance of inheriting only one mutated copy, which would result in the child being a carrier of the mutation but would not result in the disease itself
- A 25 percent chance of inheriting two normal copies of the gene
Genetic testing to understand the risk of having a child with Krabbe disease may be considered in certain situations:
- If one or both parents are likely carriers of a GALC gene mutation because of a known family history of Krabbe disease, a couple may want to have tests to understand the risks in their own family.
- If one child is diagnosed with Krabbe disease, a family may consider genetic tests to identify other children who could develop the disease later in life.
- If the parents are known carriers, they may request a prenatal genetic test to determine if their child is likely to develop the disease.
- Known carriers, who are using in vitro fertilization, may request a genetic test with fertilized eggs before implantation.
Genetic testing should be carefully considered. Ask your doctor about genetic counseling services that can help you understand the benefits, limits and implications of genetic testing.
June 03, 2014
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