What is Dihydrolipoamide Dehydrogenase Deficiency (E3 Deficiency)? Dihydrolipoamide Dehydrogenase Deficiency also known as E3 deficiency, caused by mutations in the DLD gene, is an inherited condition resulting in the deficiency of the enzyme dihydrolipoamide dehydrogenase, which disrupts multiple enzyme complexes that help break down substances in cells. This condition can cause metabolic abnormalities, neurological damage, poor muscle tone, developmental delay, and movement problems. Infants with E3 deficiency often appear normal until the age of eight weeks to six months, when they develop a severe buildup of lactic acid in the body (lactic acidosis) that causes vomiting, abdominal pain, and rapid breathing. If untreated, this condition can be fatal. Infants and children with the disease can have developmental delay and a progressive breakdown of their nervous system. They often have poor muscle tone (hypotonia) and abnormal movements. The disease is also called maple syrup urine disease type 3, due to the characteristic maple-syrup-like smell of their urine. How Common Is E3 Deficiency? The prevalence of E3 deficiency in the general population is unknown. The majority of known cases come from families of Ashkenazi Jewish background, where the prevalence is 1 in 35,000 to 1 in 48,000. How Is E3 Deficiency Treated? There is no established treatment for E3 deficiency. Combinations of diet, vitamins, and supplements have been tried without much success. What Is the Prognosis for an Individual with E3 Deficiency? While the number of known cases does not allow for a well-established prognosis, it is thought that most individuals with E3 deficiency will die during childhood. Other names fordihydrolipoamide dehydrogenase deficiency E3 deficient MSUD Lipoamide dehydrogenase deficiency MSUD type 3 Maple syrup urine disease type 3 References Hong et al., 1996, Hum Mol Genet, 5(12):1925-30, PMID: 8968745 OMIM: Online Mendelian Inheritance in Man, OMIM , 2016, http://www.omim.org/246900 Quinonez et al., 2014, https://www.ncbi.nlm.nih.gov/books/NBK220444/ Shaag et al., 1999, Am J Med Genet, 82(2):177-82, PMID: 9934985 Resources Maple Syrup Urine Disease Family Support Group A support group to people with MSUD and their families, the organization helps to raise awareness for the disease. Phone: 740-972-5619 Genetic Disorder Fact Sheets A fact sheet on MSUD by a collaborative effort among state agencies in Alaska, California, Hawaii, Idaho, Oregon, and Washington to investigate the financial, legal, ethical, and social implications of programs that screen newborns for certain diseases. Genetics Home Reference- Dihydrolipoamide dehydrogenase deficiency Explanations of an extensive number of genetic diseases, written for everyday people by the U.S. government's National Institutes of Health.