Complex multisystem phenotype associated with the mitochondrial DNA m.5522G>A mutation.

Mitochondrial tRNAs are responsible for more than half of pathogenic point mutations in the mitochondrial genome (mtDNA). Different mutations give rise to widely differing phenotypes, ranging from isolated organ-specific diseases to multisystem conditions. Herein, we report a 40-year-old woman presenting with a complex multisystem phenotype including sensorineural hearing loss, retinopathy, severe dilated cardiomyopathy, non-insulin dependent diabetes mellitus, and renal failure. Sequence analysis of mtDNA identified the m.5522G>A mutation in MT-TW, the gene encoding mitochondrial tRNA for tryptophan. The heteroplasmic variant, thus far described once, was almost exclusively confined to skeletal muscle tissue, as shown by massive parallel sequencing and corroborated by an ad hoc designed PCR-based strategy. This patient, presenting a severe, multisystem involvement apparently sparing the brain, contributes to the genetic heterogeneity of mitochondrial diseases caused by mutations in mitochondrial tRNAs.

The Diagnostic Approach to Mitochondrial Disorders in Children in the Era of Next-Generation Sequencing: A 4-Year Cohort Study.

Mitochondrial diseases (MDs) are a large group of genetically determined multisystem disorders, characterized by extreme phenotypic heterogeneity, attributable in part to the dual genomic control (nuclear and mitochondrial DNA) of the mitochondrial proteome. Advances in next-generation sequencing technologies over the past two decades have presented clinicians with a challenge: to select the candidate disease-causing variants among the huge number of data provided. Unfortunately, the clinical tools available to support genetic interpretations still lack specificity and sensitivity. For this reason, the diagnosis of MDs continues to be difficult, with the new "genotype first" approach still failing to diagnose a large group of patients. With the aim of investigating possible relationships between clinical and/or biochemical phenotypes and definitive molecular diagnoses, we performed a retrospective multicenter study of 111 pediatric patients with clinical suspicion of MD. In this cohort, the strongest predictor of a molecular (in particular an mtDNA-related) diagnosis of MD was neuroimaging evidence of basal ganglia (BG) involvement. Regression analysis confirmed that normal BG imaging predicted negative genetic studies for MD. Psychomotor regression was confirmed as an independent predictor of a definitive diagnosis of MD. The findings of this study corroborate previous data supporting a role for neuroimaging in the diagnostic approach to MDs and reinforce the idea that mtDNA sequencing should be considered for first-line testing, at least in specific groups of children.

Movement Disorders in Children with a Mitochondrial Disease: A Cross-Sectional Survey from the Nationwide Italian Collaborative Network of Mitochondrial Diseases.

Movement disorders are increasingly being recognized as a manifestation of childhood-onset mitochondrial diseases (MDs). However, the spectrum and characteristics of these conditions have not been studied in detail in the context of a well-defined cohort of patients. We retrospectively explored a cohort of individuals with childhood-onset MDs querying the Nationwide Italian Collaborative Network of Mitochondrial Diseases database. Using a customized online questionnaire, we attempted to collect data from the subgroup of patients with movement disorders. Complete information was available for 102 patients. Movement disorder was the presenting feature of MD in 45 individuals, with a mean age at onset of 11 years. Ataxia was the most common movement disorder at onset, followed by dystonia, tremor, hypokinetic disorders, chorea, and myoclonus. During the disease course, most patients (67.7%) encountered a worsening of their movement disorder. Basal ganglia involvement, cerebral white matter changes, and cerebellar atrophy were the most commonly associated neuroradiological patterns. Forty-one patients harbored point mutations in the mitochondrial DNA, 10 carried mitochondrial DNA rearrangements, and 41 cases presented mutations in nuclear-DNA-encoded genes, the latter being associated with an earlier onset and a higher impairment in activities of daily living. Among our patients, 32 individuals received pharmacological treatment; clonazepam and oral baclofen were the most commonly used drugs, whereas levodopa and intrathecal baclofen administration were the most effective. A better delineation of the movement disorders phenotypes starting in childhood may improve our diagnostic workup in MDs, fine tuning management, and treatment of affected patients.

Evaluation of Chromosome Microarray Analysis in a Large Cohort of Females with Autism Spectrum Disorders: A Single Center Italian Study.

Autism spectrum disorders (ASD) encompass a heterogeneous group of neurodevelopmental disorders resulting from the complex interaction between genetic and environmental factors. Thanks to the chromosome microarray analysis (CMA) in clinical practice, the accurate identification and characterization of submicroscopic deletions/duplications (copy number variants, CNVs) associated with ASD was made possible. However, the widely acknowledged excess of males on the autism spectrum reflects on a paucity of CMA studies specifically focused on females with ASD (f-ASD). In this framework, we aim to evaluate the frequency of causative CNVs in a single-center cohort of idiopathic f-ASD. Among the 90 f-ASD analyzed, we found 20 patients with one or two potentially pathogenic CNVs, including those previously associated with ASD (located at 16p13.2 16p11.2, 15q11.2, and 22q11.21 regions). An exploratory genotype/phenotype analysis revealed that the f-ASD with causative CNVs had statistically significantly lower restrictive and repetitive behaviors than those without CNVs or with non-causative CNVs. Future work should focus on further understanding of f-ASD genetic underpinnings, taking advantage of next-generation sequencing technologies, with the ultimate goal of contributing to precision medicine in ASD.

Export of pharmaceuticals and medical devices under the federal Food, Drug & Cosmetic Act: FDA's striking change in interpretation post-Shelhigh.

With no communication to industry except court filings in United States v. Undetermined Quantities of Boxes of Articles of Device (Shelhigh) and a draft guidance document, the Food and Drug Administration (FDA) has articulated new policies regarding export of pharmaceutical products and medical devices. FDA's departure from its historic interpretation of the export provisions of the Federal Food, Drug, and Cosmetic Act (FDCA) significantly limits the ability of manufacturers to export misbranded drugs and medical devices that FDA deems "adulterated," contrary to the plain language and legislative intent of the FDCA. To further exacerbate the issue, FDA has begun to implement these policies without the notice-and-comment rulemaking required by the Administrative Procedures Act (APA), but rather through an enforcement proceeding brought in the United States District Court for the District of New Jersey. In a letter opinion, the District Court prevented the export of Current Good Manufacturing Practices (CGMP) --adulterated medical devices that complied with FDCA Section 801(e)(1), at least as historically interpreted by FDA. The purpose of this article is to review the history of FDA's export policies for pharmaceuticals and medical devices, particularly those aspects of the export policies that are affected by FDA's recent change in position. Three changes in FDA's interpretation of the export provisions of the FDCA will be addressed: 1) unapproved devices that a manufacturer reasonably believes are eligible for Section 510(k) clearance may no longer be exported under Section 801(e) and now must be exported under Section 802, in substantial compliance with Current CGMP; 2) adulterated devices and misbranded drugs can only be exported if the foreign purchaser's specifications cause the product to be adulterated; and 3) an article may not be exported if a like article has ever been sold or offered for sale in domestic commerce. FDA's new interpretations of FDCA Sections 801 and 802 are not valid interpretations of these statutory provisions. Although FDA always exercised its enforcement discretion under the FDCA with respect to export of an unapproved device that a manufacturer reasonably believed to be eligible for Section 510(k) clearance, FDA's recent shift in interpretation contravenes its longstanding approach without sufficient public notice.

Next-generation sequencing approach to hyperCKemia: A 2-year cohort study.

OBJECTIVE: Next-generation sequencing (NGS) was applied in molecularly undiagnosed asymptomatic or paucisymptomatic hyperCKemia to investigate whether this technique might allow detection of the genetic basis of the condition. METHODS: Sixty-six patients with undiagnosed asymptomatic or paucisymptomatic hyperCKemia, referred to tertiary neuromuscular centers over an approximately 2-year period, were analyzed using a customized, targeted sequencing panel able to investigate the coding exons and flanking intronic regions of 78 genes associated with limb-girdle muscular dystrophies, rhabdomyolysis, and metabolic and distal myopathies. RESULTS: A molecular diagnosis was reached in 33 cases, corresponding to a positive diagnostic yield of 50%. Variants of unknown significance were found in 17 patients (26%), whereas 16 cases (24%) remained molecularly undefined. The major features of the diagnosed cases were mild proximal muscle weakness (found in 27%) and myalgia (in 24%). Fourteen patients with a molecular diagnosis and mild myopathic features on muscle biopsy remained asymptomatic at a 24-month follow-up. CONCLUSIONS: This study of patients with undiagnosed hyperCKemia, highlighting the advantages of NGS used as a first-tier diagnostic approach in genetically heterogeneous conditions, illustrates the ongoing evolution of molecular diagnosis in the field of clinical neurology. Isolated hyperCKemia can be the sole feature alerting to a progressive muscular disorder requiring careful surveillance.

The use of Food and Drug Administration 510(k) notifications in patent litigation.

The U.S. Food and Drug Administration (FDA) 510(k) approval process provides medical device companies with the ability to market a device after the company establishes that the device to the marketed is "substantially equivalent" to one or more predicate devices. Companies that submit 510(k) notifications should be aware, however, that a 510(k) notification is a public document that may later reappear as evidence in patent litigation. Courts have considered 510(k) notifications to be relevant evidence in determining direct and contributory infringement, patent invalidity, and patent unenforceability due to inequitable conduct before the U.S. Patent and Trademark Office (USPTO). In one case, the court held that a substantial equivalence determination by FDA constituted evidence that can be "construed as an admission of infringement." The court also has relied on a 510(k) notification to support a finding of personal liability for a corporate officer who signed the 510(k) notification to be evidence of willful and deliberate conduct, and have awarded treble damages and reasonable attorney's fees to the prevailing party. The potential for increased risk in patent litigation is important for practitioners in the medical device industry, because more than seventy-five percent of medical devices are approved for marketing through the 510(k) process. This article reviews a number of patent cases in which a court has admitted a 510(k) notification as relevant evidence, and proposes general strategies for avoiding these situations.

Medical devices: the obvious, the readily-accepted, and the surprising.

The Food and Drug Administration's (FDA or the Agency) interpretation of the definition of a medical device in the Federal Food, Drug, and Cosmetic Act is very broad. Thus, the Agency has authority to regulate most products that have a health purpose or affect a person's body as medical devices unless they are clearly drugs or biologics. The primary purposes of this article are to help executives, managers, attorneys, regulatory professionals, healthcare providers, and consumers: (1) identify products that are potentially medical devices; (2) determine whether FDA is likely to regulate them as medical devices; and (3) if so, determine the applicable premarket requirements, if any. This article discusses the statutory criteria of a product's intended use, technological characteristics, and mode of action, and shows how FDA applies these criteria to determine whether a product is a medical device. This article provides examples of the Agency's interpretation of the statutory definition of a medical device and shows how to analyze whether a product is an FDA-regulated medical device.