Background: MPS VI is a multisystemic lysosomal storage disorder characterised by the accumulation of glycosaminoglycans (GAG) in lysosomes. The disorder affects most tissues of the body including the viscera, bone, cartilage and fibrous tissue. Enzyme replacement therapy (ERT), has drastically changed the disease course in MPS VI, however much remains unknown about longterm therapy. Case Report: We describe a female patient with rapidly progressive MPS VI who commenced ERT at 9 years of age and died at 16. Electron microscopy (EM) was performed on the tissues of a toe removed 6 months after commencing enzyme replacement therapy and on a contralateral toe at autopsy after almost 7 years of ERT. Results: Intital EM demonstrated significant staorage of GAGs in the cells of the bone, cartilage and fibrous tissue. Autopsy microscopy showed minimal to no storage of GAGs in bone or cartilage, but persistent storage in fibrous tissue. Conclusions: In this case there appeared to be microscopic clearance of storage from bone and cartilage, but not fibrous tissue. The differences observed may reflected differential cell turnover in bone and cartilage compared to fibrous tissue. This finding provides human evidence that ERT may influence the disease process in bone and cartilage. Lysosomal storage diseases constitute about 50 different diseases, with a specific lysosomal enzyme deficiency. They have characteristic features, and diagnosis must be established with specific biochemical assay or by DNA analysis. There is no specific cure for these disorders, however, a new era has emerged in recent years in the management with Enzyme replacement therapy (ERT).Although it is not a cure but it can modify or attenuate the disease phenotype and its progression. The treatable disorders include the non-neuronopathic Gaucher Disease, MPSI, MPSII, MPSVI, Fabry disease, and Pompe Disease by ERT. Results: ERT for Gaucher, Pompe and MPS I, and Fabry is being given in India by Genzyme, USA as a charity. At rainbow children Hospital, Hyderabad, India, a total of six patients were under ERT, Response to therapy was excellent with Gaucher disease, and not very encouraging with Pompe disease and reasonably satisfactory with MPS I. Conclusions: Treatable LSD is more often diagnosed in India and option for treatment is limited in view of the cost. Hypophosphatasia (HPP) is the metabolic bone disease caused by loss-offunction mutation within the gene encoding the "tissue nonspecific" isoenzyme of alkaline phosphatase (TNSALP). Perinatal/early infantile-onset HPP is usually fatal due to respiratory insufficiency. There is no approved medical therapy. We reviewed our 80-year (1927-2007) retrospective cohort of 19 Canadian patients with perinatal/early infantile-onset HPP. 14/19 were of Mennonite descent and those available for study were homozygous for the TNSALP gly317asp mutation with profound skeletal hypomineralization, severe rickets, and respiratory insufficiency. All died by 9 months-of-age, most often soon after birth, from pulmonary failure. Clinical trials of enzyme-replacement therapy for HPP using human, recombinant, bone-targeted TNSALP (ENB-0040) began in 2008. To date, 20 infants and young children (10 perinatal; 10 infantile-onset HPP) who met eligibility criteria have been enrolled and treated with thrice weekly subcutaneous injections. 1 withdrew after the first injection and 1 died of sepsis unrelated to ENB-0040. In the remaining 18 patients, including 2 perinatal homozygous for the Canadian Mennonite mutation, marked improvement in their radiological findings and respiratory function is paralleled by dramatic clinical gains with minimal side effects. The liver is a potential target for transgene delivery and expression for gene therapy of hepatic and various metabolic diseases, including amino acid metabolism or urea cycle disorders. Currently, we are developing and evaluating highly efficient non-viral gene transfer methods by targeting the murine liver as a potential alternative gene-therapeutic approach. In our study, we report the use of the minicircle (MC) technology for the gene therapy of phenylketonuria (PKU) mouse model. Our MC-DNA vectors contain a liver-specific promoter, Pah, the luciferase reporter gene plus a downstream mammalian scaffold/matrix attachment region (S/MAR) element for episomal maintenance and/or extra-chromosomal stability. Delivery was mediated by hydrodynamic tail vein (HTV) injection as a liver-targeted approach. Luciferase expression was monitored by quantitative bioluminescence in a non-invasive imaging technology in living mice (IVIS screening). We compared longitudinal luciferase expression between MC-DNA vector and conventional plasmid DNA (pDNA). Our data showed that vectors were exclusively delivered to the liver and the luciferase expression in mice injected with MC was more than 20-fold higher than mice injected with pDNA for at least 9 months. MC gene delivery for maximizing safety and sustained gene expression is a potential new approach for the hepatic treatment. Background: Lipoprotein lipase deficiency (LPLD) is a rare, monogenic lipid disorder causing hyperchylomicronaemia, increased risk of acute pancreatitis (360 x) and cardiometabolic complications. Alipogene tiparvovec (Glybera®) contains a gain-of-function LPL-gene mutation in an AAVvector. We conducted two interventional trials and one case note review study for pancreatitis (CT-AMT-011-03). Methods: In the interventional trials involving 19 LPLD adults, alipogene tiparvovec was administered IM one-time. These patients and subjects participating in an earlier observational study were enrolled in CT-AMT-011-03. Historical data for all hospital presentations due to abdominal pain were collected. Pancreatitis definition was according to modified Atlanta Diagnostic Criteria for acute pancreatitis. Statistical analysis to model the A Cox regression gap-time-model estimating hazard of pancreatitis pre/ post therapy was used. Results: Alipogene tiparvovec was well tolerated. Adverse events were mainly injection site related, mild-moderate and transient. A statistically significant reduction in the risk of acute pancreatitis was seen comparing the period from the first pancreatitis event to administration with the post-therapy period (median=2.9 years). The hazard ratio indicated a 63% reduction in risk of acute pancreatitis (95% CI 0.142-0.971). Conclusion: Alipogene tiparvovec was well tolerated, safe and reduced the risk of pancreatitis during long term follow up post one-time administration. Conflict of Interest declared. We have previously demonstrated the successful treatment of Pahenu2 mice, a model of human PKU, following liver-directed administration of a phenylalanine hydroxylase (PAH)-expressing rAAV2/8 vector. However, the therapeutic effect of this treatment was only temporary with transgene loss and reemergence of elevated blood phenylalanine within 4-6 months after vector injection. rAAV vectors that harbor 28S ribosomal DNA (rDNA) sequences flanking the therapeutic transgene cassette have been shown in other mouse models to permanently integrate at least ten times more frequently than standard rAAV. Portal vein injection into Pahenu2 mice of a novel rAAV2/8 vector that contains a PAH expression cassette flanked by rDNA sequences yielded complete correction of blood phenylalanine within one week. The treatment effect lasted almost one year after injection. Site-specific integration of the novel vector genome into mouse 28S rDNA has been demonstrated using nested PCR, but the true integration frequency is currently being evaluated. The inclusion of rDNA sequences into rAAV2/8 vectors to direct increased frequency of site-specific integration events is a promising novel step in the development of safe, effective rAAV-mediated liver-directed gene therapy for PKU and other inborn errors of metabolism. Introduction: Current treatments for Methylmalonic Aciduria (MMA) remain unsatisfactory and research on novel therapies remains a high priority. A lentiviral (LV) vector was developed to treat an in vivo model of MMA. Aim: To examine the therapeutic effect of lentiviral vector-mediated transfer of methylmalonyl CoA mutase (MCM) gene into a MCM knockout mouse. Methods: A LV-MMA vector was developed and injected intravenously into 5 MMA mice. Untreated MMA (n=6) and normal mice (n=6) were used as controls. Mice weight was measured weekly after treatment. Plasma and urine MMA were measured using mass spectrometry and posttreatment MCM enzyme activity was determined by HPLC, according to published methods. Results: The LV-MMA treated mice achieved near-normal weight for sex. Median plasma MMA levels in the LV-MMA treated group were reduced from 909+/−365uM at baseline to 377+/−166uM at 6 months, compared to untreated MMA mice 1114+/−328.54uM. Hepatic MCM enzyme 6 months post LV therapy ranged from 1.8 to 166.1 nmol/min/ug of protein (median 130.56+/−70uM), compared to not detectable in the untreated mice (N=6). Conclusion: These results confirm that the use of LV-MMA may be a viable approach for the treatment of this form of MMA. Background: Canavan Disease (CD), caused by aspartoacylase (ASPA) deficiency is a severe leukodystrophy with no effective treatment. Earlier gene therapy attempts using rAAV2 failed. Objective: To develop novel rAAV-based therapeutics for efficacious and safe gene therapy of CD. Materials Methods and Experimental Design: ASPA−/− KO mice created by us mimic the neuropathology and clinical manifestation of CD patients, as early as the 2nd week of life and die early. Novel rAAVs developed by us efficiently cross the BBB and transduce the CNS after an i.v. injection. We used miRNAs to regulate i.v. delivered rAAV towards CNS-restricted gene expression. This novel gene therapy approach was evaluated in the CD mice. Results: Single i.v. injection of rAAVASPA postnatally corrected metabolic, psychomotor deficits and spongy degeneration of the CNS. New findings of severe retinopathogy and renal pathology that were observed in the CD mice, were corrected with Gene Therapy. This treatment prolonged the life of the mice and restored their vision. Conclusion/Discussion: Our data demonstrate the feasibility, safety and efficacy of this novel approach for gene therapy in CD. Development of clinical trials for CD patients should be the outcome of these on-going studies. Mucopolysaccharidosis type VII (MPS VII, Sly syndrome) is one of lysosomal storage diseases (LSDs) caused by deficiency of betaglucuronidase (GUSB), resulting in progressive accumulation of glycosaminoglycans (GAGs) in various tissues including the brain. In this study, we evaluated the potential to perform gene therapy for MPS VII. Methods: We constructed a lentiviral vector, SMPU-R-MND-HBG -IE, to transduce cells with the normal human HBG cDNA. We injected the neonatal mice of MPS VII, and sacrificed 7 weeks and 31 weeks after treatment and analyzed GUSB activity by 4-MU method, Lentiviral DNA bio-distribution by real-time PCR and evaluation of autophagy performed by Western-Blotting and Immune stain of LC3 protein in brain and liver. Results: GUSB enzyme activities of the treated mice were elevated in all organs and decrease GAGs in all organs and a significant deceased LC3 protein in the treated mice and indicated the organs failure in MPS VII due to autophagy. We detected lentiviral DNA expression in all organs of treated mice 7 weeks and 31 weeks. Conclusion: We have demonstrated that the neonatal gene therapy for MPS VII mice using lentiviral vector resulted in long-term and efficient GUSB expression, which corrects the biochemical defects, and decreased LC3 protein. Tetrahydrobiopterin (BH4) is an essential cofactor for phenylalanine hydroxylase (PAH), tyrosine hydroxylase (TH), and tryptophan hydroxylase (TPH). BH4 is synthesized de novo from guanosine triphosphate (GTP) by three enzymes: GTP cyclohydrolase I (GTPCH), 6pyruvoyltetrahydropterin synthase (PTPS) and sepiapterin reductase (SR). Conventional treatment of patients with BH4 cofactor deficiency due to autosomal recessive mutations in the PTS gene, encoding PTPS, requires control of elevated blood-phenylalanine (Phe) levels by BH4 supplementation and oral replacement therapy with L-dopa and 5-OH-tryptophan, precursors of dopamine (catecholamines) and serotonin, respectively. We have recently developed a viable mouse model for PTPS deficiency, the compound heterozygous Pts-ki/ko mouse, which exhibit low PTPS activity, hyperphenylalaninemia and low brain dopamine and serotonin levels. Currently we are testing a triple-gene transfer to target liver using AAV2 pseudotype 8 vectors (rAAV2/8) in combination with luciferase coexpressed for in vivo hepatic imaging. Coordinate expression of PTPS, TH and TPH is thought to lead to hepatic synthesis of BH4, L-dopa plus 5-OH-tryptophan, respectively, and eventually to restoration of systemic phenylalanine clearance and endogenous supply of the essential precursors for monoamine neurotransmitter biosynthesis in the CNS.