Background: Pompe disease is a progressive metabolic neuromuscular disorder resulting from deficiency of lysosomal acid α-glucosidase (GAA). Infantile-onset Pompe disease is characterized by cardiomyopathy, respiratory and skeletal muscle weakness, and early death. The safety and efficacy of recombinant human (rh) GAA were evaluated in 18 patients with rapidly progressing infantile-onset Pompe disease. Methods: Patients were diagnosed at 6 months of age and younger and exhibited severe GAA deficiency and cardiomyopathy. Patients received IV infusions of rhGAA at 20 mg/kg (n = 9) or 40 mg/kg (n = 9) every other week. Analyses were performed 52 weeks after the last patient was randomized to treatment. Results: All patients (100%) survived to 18 months of age. A Cox proportional hazards analysis demonstrated that treatment reduced the risk of death by 99%, reduced the risk of death or invasive ventilation by 92%, and reduced the risk of death or any type of ventilation by 88%, as compared to an untreated historical control group. There was no clear advantage of the 40-mg/kg dose with regard to efficacy. Eleven of the 18 patients experienced 164 infusion-associated reactions; all were mild or moderate in intensity. Conclusions: Recombinant human acid α-glucosidase is safe and effective for treatment of infantile-onset Pompe disease. Eleven patients experienced adverse events related to treatment, but none discontinued. The young age at which these patients initiated therapy may have contributed to their improved response compared to previous trials with recombinant human acid α-glucosidase in which patients were older.

Significance: The energy-producing organelle mitochondrion contains its own compact genome, which is separate from the nuclear genome. In nearly all mammals, this mitochondrial genome is inherited exclusively from the mother, and transmission of paternal mitochondria or mitochondrial DNA (mtDNA) has not been convincingly demonstrated in humans. In this paper, we have uncovered multiple instances of biparental inheritance of mtDNA spanning three unrelated multiple generation families, a result confirmed by independent sequencing across multiple unrelated laboratories with different methodologies. Surprisingly, this pattern of inheritance appears to be determined in an autosomal dominantlike manner. This paper profoundly alters a widespread belief about mitochondrial inheritance and potentially opens a novel field in mitochondrial medicine.

Fabry disease (α‐galactosidase A (α‐Gal A, GLA) deficiency) is a panethnic inborn error of glycosphingolipid metabolism. Because optimal therapeutic outcomes depend on early intervention, a pilot program was designed to assess newborn screening for this disease in 171,977 consecutive Taiwanese newborns by measuring their dry blood spot (DBS) α‐Gal A activities and β‐galactosidase/α‐Gal A ratios. Of the 90,288 male screenees, 638 (0.7%) had DBS α‐Gal A activity 10. A second DBS assay reduced these to 91 (0.1%). Of these, 11 (including twins) had 30% (Group‐C) of mean normal leukocyte α‐Gal A activity. All 11 Group‐A, 61 Group‐B, and 1 Group‐C males had GLA gene mutations. Surprisingly, 86% had the later‐onset cryptic splice mutation c.936+919G>A (also called IVS4+919G>A). In contrast, screening 81,689 females detected two heterozygotes. The novel mutations were expressed in vitro, predicting their classical or later‐onset phenotypes. Newborn screening identified a surprisingly high frequency of Taiwanese males with Fabry disease (∼1 in 1,250), 86% having the IVS4+919G>A mutation previously found in later‐onset cardiac phenotype patients. Further studies of the IVS4 later‐onset phenotype will determine its natural history and optimal timing for therapeutic intervention. Hum Mutat 30:1–9, 2009.

Aromatic l-amino acid decarboxylase (AADC) is required for the synthesis of the neurotransmitters dopamine and serotonin. Children with defects in the AADC gene show compromised development, particularly in motor function. Drug therapy has only marginal effects on some of the symptoms and does not change early childhood mortality. Here, we performed adeno-associated viral vector–mediated gene transfer of the human AADC gene bilaterally into the putamen of four patients 4 to 6 years of age. All of the patients showed improvements in motor performance: One patient was able to stand 16 months after gene transfer, and the other three patients achieved supported sitting 6 to 15 months after gene transfer. Choreic dyskinesia was observed in all patients, but this resolved after several months. Positron emission tomography revealed increased uptake by the putamen of 6-[¹⁸F]fluorodopa, a tracer for AADC. Cerebrospinal fluid analysis showed increased dopamine and serotonin levels after gene transfer. Thus, gene therapy targeting primary AADC deficiency is well tolerated and leads to improved motor function.

OBJECTIVE. Pompe disease is an autosomal recessive lysosomal storage disorder that is caused by deficient acid α-glucosidase activity and results in progressive, debilitating, and often life-threatening symptoms involving the musculoskeletal, respiratory, and cardiac systems. Recently, enzyme replacement therapy with alglucosidase α has become possible, but the best outcomes in motor function have been achieved when treatment was initiated early. The aim of this study was to test the feasibility of screening newborns in Taiwan for Pompe disease by using a fluorometric enzymatic assay to determine acid α-glucosidase activity in dried blood spots. METHODS. We conducted a large-scale newborn screening pilot program between October 2005 and March 2007. The screening involved measuring acid α-glucosidase activity in dried blood spots of ∼45% of newborns in Taiwan. The unscreened population was monitored as a control. RESULTS. Of the 132 538 newborns screened, 1093 (0.82%) repeat dried blood-spot samples were requested and retested, and 121 (0.091%) newborns were recalled for additional evaluation. Pompe disease was confirmed in 4 newborns. This number was similar to the number of infants who received a diagnosis of Pompe disease in the control group (n = 3); however, newborn screening resulted in an earlier diagnosis of Pompe disease: patients were <1 month old compared with 3 to 6 months old in the control group. CONCLUSIONS. To our knowledge, this is the first large-scale study to show that newborn screening for Pompe disease is feasible. Newborn screening allows for earlier diagnosis of Pompe disease and, thus, for assessment of the value of an earlier start of treatment.