Lipoamide dehydrogenase deficiency is an inherited disease with an autosomal recessive inheritance pattern. This means that to develop this disease, two mutated copies of the relevant gene must be inherited, one from a person’s mother and one from their father.
Diagnosis and genetic testing
Unlike prenatal screening tests offered to parents-to-be in the general population, genetic testing for this disease is offered only to families of Ashkenazi Jewish descent. While the prevalence of the gene mutation in Ashkenazi Jewish people is 1 in 100 people, the disease does not appear at all in other groups of the population. This is a very rare disease with less than 20 cases known worldwide.
Genetic testing is first performed on one partner and if they are found to be carriers of the gene mutation, testing is performed also on the other partner. If both partners are carriers, their chances of having a child with this disease are 25%.
Two main mutations to the gene encoding the enzyme Lipoamide dehydrogenase are known to cause the disease in 95% of patients.
What are the symptoms?
Symptoms can develop at different ages and vary according to age of onset. In most cases, symptoms develop between the age of eight weeks to six months. Symptoms include:
- Recurring abdominal pain, vomiting, and encephalopathy.
- Poor muscle tone (hypotonia).
- Developmental delay.
- Neurological dysfunction.
- Rapid breathing and hyperventilation.
- Death within the first years of life.
- Maple syrup urine disease (this disease is sometimes also called maple syrup urine disease type 3).
Since this is an extremely rare disease, there is currently no treatment for LDD. The disease is managed through dietary restrictions, supplement intake, and medical interventions in cases of acute acid buildup.