| Main clinical features
|
feeding difficulties, weakness, lethargy and decreasing responsiveness within a few days after both associated to lactid acidosis, hyperglycinemia defect of multiple mitochondrial functions; first symptoms started at age 1–9 months, and all the individuals died on or before the age of 15 months
blood revealed high levels of glycine, leucine, valine, and isoleucine, indicating abnormalities of the glycine-cleavage system and of the branched-chain alpha-keto acid dehydrogenase, and a significant reduction in activity of mitochondrial respiratory chain complexes |