The following information may help to address your question:
What is isobutyryl-CoA dehydrogenase deficiency?
Isobutyryl-CoA dehydrogenase deficiency (IBD deficiency) is an inborn error of valine (an
amino acid) metabolism.
[1] The symptoms, which may not develop until later in infancy or childhood, can include
failure to thrive,
dilated cardiomyopathy,
seizures, and
anemia.
[2][3] IBD deficiency is caused by
mutations in the
ACAD8 gene.
[1][2] It is
inherited in an
autosomal recessive manner.
[2][3] Treatment may include the use of
L-carnitine (a safe and natural substance that helps the body's
cells make energy), frequent meals, and a low-valine diet.
[3]
Last updated: 6/19/2016
What are symptoms of isobutyryl-CoA dehydrogenase deficiency (IBD deficiency)?
Infants with IBD deficiency usually appear healthy at birth. Some children identified with the condition through
newborn screening never develop symptoms. When symptoms do occur, they tend to vary, but may include poor feeding and growth (
failure to thrive), a weakened and enlarged heart (
dilated cardiomyopathy), seizures, and low numbers of
red blood cells (
anemia). Another feature of this disorder may be very low blood levels of carnitine (a natural substance that helps convert certain foods into energy). IBD deficiency may be worsened by long periods without food (fasting) or infections that increase the body's demand for energy.
[2][3]
Last updated: 6/19/2016
What causes isobutyryl-CoA dehydrogenase deficiency (IBD deficiency)?
IBD deficiency is caused by mutations in the
ACAD8 gene.
[1][2] The
ACAD8 gene provides instructions for making an
enzyme that plays an essential role in breaking down
proteins from the diet. Specifically, the enzyme is responsible for processing valine, an amino acid that is part of many proteins. If a mutation in the
ACAD8 gene reduces or eliminates the activity of this enzyme, the body is unable to break down valine properly. As a result, poor growth and reduced energy production may occur.
[2]
Last updated: 6/19/2016
How is isobutyryl-CoA dehydrogenase deficiency (IBD deficiency) inherited?
IBD deficiency is inherited in an
autosomal recessive manner.
[2][3] This means that to be affected, a person must have a
mutation in both copies of the responsible
gene in each cell. Affected people inherit one mutated copy of the gene from each parent, who is referred to as a
carrier. Carriers of an autosomal recessive condition typically do not have any signs or symptoms (they are unaffected). When 2 carriers of an autosomal recessive condition have children, each child has a:
- 25% (1 in 4) chance to be affected,
- 50% (1 in 2) chance to be an unaffected carrier like each parent,
- 25% (1 in 4) chance to be unaffected and not be a carrier.
Last updated: 6/19/2016
How is isobutyryl-CoA dehydrogenase deficiency (IBD deficiency) treated?
There is no standard treatment protocol for IBD deficiency. Infants diagnosed through newborn screening are encouraged to work with a metabolic disease specialist and a dietician experienced in metabolic disorders. Some treatments may be recommended even if no symptoms have been observed. Treatment may be needed throughout life. The following treatments may be recommended for some babies and children with IBD deficiency.[3]
- Children with IBD deficiency may be helped by taking L-carnitine, a safe and natural substance which helps the body's cells make energy and get rid of harmful wastes. L-carnitine may also help to prevent or treat the heart problems and anemia seen in children with IBD deficiency.
- Some infants and children with IBD deficiency may be advised to avoid fasting. Going without food for a long time causes the body to use its stores of fat and protein for energy. In some people with IBD deficiency, this may lead to the build up of harmful substances in the blood. Eating frequently (every 4 to 6 hours) may help to avoid these health effects.
- While most children with IBD deficiency do fine without a change in diet, a low-valine food plan might be necessary. Valine is found in all foods with protein. Foods high in valine, such as dairy products, meat, poultry, fish, eggs, dried beans and legumes, nuts and peanut butter should be limited. There are medical foods such low-protein flours, pastas, rice, and special formulas that are made especially for people with organic acid disorders. Your dietician / physician can advise you on whether you should use these foods to supplement your child’s diet.
Last updated: 6/19/2016
What happens if isobutyryl-CoA dehydrogenase deficiency (IBD deficiency) is treated? Does it go away?
While IBD deficiency will never 'go away', it is thought that with prompt and careful treatment, children this condition will be able to live healthy lives with typical growth and development. Treatment with carnitine is believed to reverse the heart problems and anemia associated with this condition and may improve growth.
[3]
Last updated: 6/19/2016
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GARD Information Specialist
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