Gavrilova RH 1 , Gurrieri C 1 , Weingarten TN 1 , Sprung J 1 1 Mayo Clinic, Rochester, United States MELAS could progresses to multiorgan pathology and early death. Impaired integration of pyruvate into Krebs cycle predisposes to lacticademia and increased perioperative risk. Controversy exists regarding increased susceptibility to certain anesthetics and malignant hyperthermia. Avoidance of lactated intravenous fluids (LR) was advocated because of impaired lactate metabolism. We describe outcomes of MELAS patients who underwent surgery at Mayo Clinic, USA. Perioperative data of confirmed MELAS patients were retrospectively characterized. 9 patients underwent anesthesia for 20 surgeries: general anesthesia with volatile anesthetics in 14; propofol-3; NMDA-14; succinylcholine-4. Lack of need for excessive amounts NMDA was not suggestive for resistance. Recovery from NDMR blockade appeared uneventful. Most patients were receiving levetiracetam/topiramate which do not alter response to NMDA. One had severe myopathy, succinylcholine was not used. MH triggering agents were routinely used without evidence of MH. Intraoperative LR in 13 cases did not result in acid-base decompensation. MELAS patients did not show aberrant response to muscle relaxants and to anesthesia management in this study. Response to muscle relaxants may depend on interplay between medications/antiepileptics and myopathy. NMDA should be dosed with aid of neuromuscular monitoring. Alterations of acid-base balance not encountered despite administration of LR. Background: Kearns-Sayre syndrome (KSS) is a mitochondrial disorder presenting as main biochemical findings high CSF protein and low 5methyltetrahydrofolate (5-MTHF) values, which reflect impaired transport across choroid plexus. Other compounds may also be affected. Our aim was to assess different biochemical parameters that may detect choroid plexus dysfunction in KSS patients. Methods: We studied 7 patients genetically diagnosed with KSS. The measured parameters in CSF were total proteins, 5-MTHF, homovanillic acid (HVA) and Selenium (Se) concentrations. Results: Together with high CSF Se values, increased CSF HVA and total protein concentrations and decreased CSF 5-MTHF values were observed in all cases. This pattern was only detected in the 7 KSS patients of 1,850 CSF samples analyzed in our laboratory during the last 6 years. Conclusions: The application of these biochemical analyses may allow early identification of new cases with undiagnosed KSS. These impaired metabolites seem very specific and may represent a good biochemical model for evaluating choroid plexus dysfunction. The accumulated Se in CSF might have cause toxicity effects or increased dopamine turnover. This last feature would be reflected by increased CSF HVA (marker of dopamine turnover). The association between Se and HVA and its possible clinical implications deserve further investigation. Human cytochrome c oxidase (COX) contains two copper centers CuA and CuB that are essential for enzyme catalytic activity. Aim of our study was to analyze copper content and COX activity and amount in muscle, liver, heart and brain tissue obtained at autopsy from 17 children with mutations in SURF1 (7x), SCO2 (9x) and SCO1 (1x) genes. Copper content was analyzed by atomic absorption spectrometry. COX activity and amount were analyzed by spectrophotometric and immunoelectroforetic methods. The copper content was more than 4-fold reduced in SCO2 and SURF1 liver in comparison with age related controls and more than 3-fold in SURF1 skeletal muscle. The severe copper deficiency of SCO1 muscle (5fold) was accompanied by 6-fold decrease of COX activity. The SCO2 heart showed 3-fold reduction of copper content and 10-fold reduction of COX activity. The SCO2 and SURF1 frontal cortex specimens displayed either normal or borderline copper levels although all of the SCO2 and SURF1 patients suffered from severe CNS involvement. While the copper deficient phenotype of SCO1/SCO2 tissues appears consistent with the function of both gene products in regulation of cellular copper homeostasis, the severe copper deficiency of SURF1 deficient tissues remains elusive. Supported by MSM0021620806, IGA-MZ-NS 10581/3, GAUK28410 In a family three children presented with severe neonatal lactic acidosis, hypertrophic cardiomyopathy and generalized muscular hypotonia. One child died in infancy, two survived a clinically severe neonatal period. At an age of 9 and 17 years, respectively, they present with exercise intolerance, proximal muscle weakness, non progressive hypertrophic cardiomyopathy and normal mental development. In a muscle biopsy normal activity of respiratory chain enzymes were found, however the amount of the mitochondrial phosphate carrier was decreased. This protein is expressed in two tissue-specific isoforms generated by mutually exclusive alternative splicing of the SLC25A3 gene transcript. We identified a homozygous mutation c.158-9A>G located in the 5'-intron next to exon 3A specific for heart and skeletal muscle. This creates a novel splice site resulting in a more than 95% decrease of the wild type allele. Although early onset mitochondrial liver disease is often rapidly fatal, there is spontaneous reversal in a small number of cases and these have a good long term prognosis. Identification of causative genetic defects in these patients has an important bearing on management decisions. A female neonate presented on day 6 with poor feeding, weight loss, jaundice and lactic acidosis. Serum transaminases were elevated and there was a coagulopathy. Liver histology showed distorted architecture and necrosis. Cytochrome oxidase activity in liver and muscle was profoundly reduced. However, by 3 months, she was progressing well and liver function, blood lactate and muscle cytochrome oxidase activity had all normalised. She is now developing appropriately. Two pathogenic mutations, c.835 G>A (V279M) and IVS11-3, C>G, were identified in the TRMU gene. This gene encodes an enzyme involved in mitochondrial tRNA modification and was initially recognised as a modifier of deafness due to the mtDNA A1555G mutation. Recently a small number of infants have been reported with mutations in this gene and reversible liver disease. It is therefore important to screen the TRMU gene in patients with early onset liver disease and lactic acidosis to identify those who will be expected to have a benign course. Deficiency of the pyruvate dehydrogenase E3 binding protein (E3BP) was identified in two sisters, the offspring of consanguineous Portuguese parents. The sisters, currently aged 17 and 27 years, both have episodic weakness and painful dystonic posturing of the torso and limbs associated with intercurrent illnesses. In addition, the older sib is prone to selfmutilation and aggressive outbursts, whilst the younger girl has an anxiety disorder. Dichloroacetate and a ketogenic diet appeared to be of some benefit, but triheptanoin oil was not tolerated. Both sisters have nonprogressive moderate to severe learning disability and modest elevations of blood and CSF lactate. Fibroblast pyruvate dehydrogenase activity was significantly reduced in both girls and there was a homozygous base substitution in the splice acceptor site of intron 7 of the PDHX gene, resulting in skipping of exon 8 and generation of a premature stop codon. Patients with complete E3BP deficiency have some residual enzyme activity, which may allow prolonged survival, although not usually to the extent seen in these sisters. A dystonic movement disorder developing during childhood is increasingly being recognised as a major manifestation of less acute presentations of pyruvate dehydrogenase deficiency, particularly those involving the E2 and E3BP subunits of the complex. Pyruvate dehydrogenase complex (PDC) deficiency is one of the most common neurodegenerative disorders associated with abnormal mitochondrial metabolism. The key feature is gray matter degeneration with foci of necrosis and capillary proliferation in the brainstem. Lactic acidosis with normal/low Lactate/Pyruvate is the main biochemical marker. The most common cause is mutations in the X-linked E1 alpha gene (PDH1 gene). Two girls with mutation c.904 C>T in the 10th exon of PDH1 gene have been diagnosed in Estonia. Before enzymatic/mutation analysis, organic and amino acids analysis in serum and urine were performed to determine lactate, pyruvate and alanine. For both analysis in serum protein was precipitated using 10% sulfosalicylic acid (0.25 ml for 1 ml of serum). Lactate and pyruvate in serum were elevated: 3400/372 μmol/l and 4060/ 1152 μmol/l (normal 3300/160 μmol/l). L/P was relatively low (< 10). Alanine in serum was elevated only in pt. I-829 μmol/l (N<495). In urine lactate, pyruvate and alanine were elevated in pt. II-4209 (N<151), 5146 (N<130) and 358 (N<254) mmol/mol creatinine. Conclusion: In both cases lactate and pyruvate were elevated in serum (L> 3000 μmol/l, P>300 μmol/l) with low L/P<10, which is specific to PDH deficiency. Background: Defects of both the pyruvate dehydrogenase complex and the mitochondrial respiratory chain are well recognised. It has been observed that patients with disease affecting the mitochondrial respiratory chain may have secondary defects of the pyruvate dehydrogenase complex, and vice versa. The interaction between these two systems is not fully understood. Aims: To identify how common it is to find deficiencies in both assays, to determine if it is possible to establish which is the likely primary defect and to comment on possible pathological mechanisms. Methods: The pyruvate dehydrogenase complex and mitochondrial respiratory chain assay results of patients from the north of England from January 1994 to December 2009 were matched. Results: The final data set was from January 1999 to December 2009. In total two hundred and thirty-nine pyruvate dehydrogenase complex assays were performed. Eighty-five were abnormal of which seventeen also had an abnormal mitochondrial respiratory complex. The majority had a complex I deficiency and, in all groups, the majority presented with a Leigh like illness. Conclusions: Advances in laboratory techniques means that more patients now receive a genetic diagnosis; this allows determination of the primary pathology and aids counseling. We report on 6 female patients with pyruvate dehydrogenase complex (PDHC) deficiency and a heterogeneous clinical and biochemical presentation. In all patients functional investigations of the mitochondrial energy metabolism were performed. The oxidation rates of pyruvate substrates were clearly decreased in 3/6 and mildly decreased in another 2/6. One patient had normal activities of the substrate oxidation rates. The activity of PDHC, however, was reduced only in 2 of the patients. Remarkably western blot analysis showed a reduced amount of E1α in relation to the other PDHC subunit in all patients. Analysis of PDHA1 gene expression showed an expression of the mutated allele in the range of 45-75% in the muscle biopsies of our patients. Sequence analysis of the X chromosomal PDHA1 gene revealed 4 novel missense mutations at conserved positions, 1 novel insertion-deletion and 1 large deletion, which also affected several neighbouring genes. All mutations were heterozygous. Heterozygous X-chromosomal diseases are a diagnostic challenge since the severity of the diseases depends on X-inactivation, which can be heterogeneous in different tissues. Concerning biochemical investigations 83% of the patients were detected by functional investigations of intact mitochondria while PDHC enzyme activity was decreased only in 33%.