Abnormalities, Multiple/genetics; Energy Metabolism/genetics; Epilepsy/genetics; Glycine/blood; Mitochondria/metabolism; Sulfurtransferases/deficiency; Abnormalities, Multiple/diagnosis; Abnormalities, Multiple/enzymology; Acidosis, Lactic/genetics; Amino Acid Sequence; Base Sequence; Chromosomes, Human, Pair 4; Consanguinity; Epilepsy/diagnosis; Epilepsy/enzymology; Escherichia coli/genetics; Escherichia coli/growth & development; Fatal Outcome; Fibroblasts/metabolism; Gene Expression; Glycine/urine; Homozygote; Humans; Infant, Newborn; Infant, Newborn, Diseases/diagnosis; Infant, Newborn, Diseases/enzymology; Infant, Newborn, Diseases/genetics; Male; Mitochondria/enzymology; Molecular Sequence Data; Muscle Hypotonia/genetics; Muscle, Skeletal/enzymology; Mutation, Missense; Pyruvate Dehydrogenase Complex/genetics; Pyruvate Dehydrogenase Complex/metabolism; Sequence Analysis, DNA