Sex differences in ischemic stroke during COVID-19 first outbreak in northern Italy.

INTRODUCTION: COVID-19 pandemic had a great impact on outcome in SARS-CoV-2 positive patients with ischemic stroke during the first wave in Italy. Few data are available on outcome stratified by sex. METHODS: The Italian Society of Hospital Neuroscience conducted a multi-center, retrospective, observational study on neurological complications in COVID-19 patients with ischemic stroke. All the patients admitted from March 1st to April 30th, 2020 in 20 Neurology Units in Northern Italy were recruited. Demographical and clinical features, treatment and outcome data were compared focusing on sex differences. RESULTS: 812 patients with ischemic stroke were enrolled, of whom 129 with COVID-19; males were 53.8%. In-hospital mortality in COVID-19 patients was 35.3% in males and 27.9% in females while 8.5% in male and 5.8% in female patients without COVID-19. SARS-CoV-2 positive patients had a higher frequency of stroke of undetermined etiology, than negative ones (32.8% vs 22.5%; p = 0.02), especially in females compared to males (36.1% vs 27.9%), albeit without statistical significance. Male patients with SARS-CoV-2 were more likely to require cPAP (30.9% vs 14.8%; p = 0.03), endotracheal tube (14.9% vs 3.3%; p = 0.02) and reperfusion strategies (29.4% vs 11.5%; p = 0.01) than females, as well as to have a higher CRP and D-dimer. These elements together with older age, a total anterior circulation stroke and lymphopenia were predictors of a worse outcome. DISCUSSION: Our study detected some differences due to sex in ischemic stroke with and without COVID-19, supporting the possibility to perform sex analyses for SARS-CoV-2 positive patients for a better clinical management.

Risk Profile of Patients with Spontaneous Cervical Artery Dissection.

OBJECTIVE: Epidemiological data to characterize the individual risk profile of patients with spontaneous cervical artery dissection (sCeAD) are rather inconsistent. METHODS AND RESULTS: In the setting of the Italian Project on Stroke in Young Adults Cervical Artery Dissection (IPSYS CeAD), we compared the characteristics of 1,468 patients with sCeAD (mean age = 47.3 ± 11.3 years, men = 56.7%) prospectively recruited at 39 Italian centers with those of 2 control groups, composed of (1) patients whose ischemic stroke was caused by mechanisms other than dissection (non-CeAD IS) selected from the prospective IPSYS registry and Brescia Stroke Registry and (2) stroke-free individuals selected from the staff members of participating hospitals, matched 1:1:1 by sex, age, and race. Compared to stroke-free subjects, patients with sCeAD were more likely to be hypertensive (odds ratio [OR] = 1.65, 95% confidence interval [CI] = 1.37-1.98), to have personal history of migraine with aura (OR = 2.45, 95% CI = 1.74-3.34), without aura (OR = 2.67, 95% CI = 2.15-3.32), and family history of vascular disease in first-degree relatives (OR = 1.69, 95% CI = 1.39-2.05), and less likely to be diabetic (OR = 0.65, 95% CI = 0.47-0.91), hypercholesterolemic (OR = 0.75, 95% CI = 0.62-0.91), and obese (OR = 0.41, 95% CI = 0.31-0.54). Migraine without aura was also associated with sCeAD (OR = 1.81, 95% CI = 1.47-2.22) in comparison with patients with non-CeAD IS. In the subgroup of patients with migraine, patients with sCeAD had higher frequency of migraine attacks and were less likely to take anti-migraine preventive medications, especially beta-blockers, compared with the other groups. INTERPRETATION: The risk of sCeAD is influenced by migraine, especially migraine without aura, more than by other factors, increases with increasing frequency of attacks, and seems to be reduced by migraine preventive medications, namely beta-blockers. ANN NEUROL 2023;94:585-595.

Antithrombotic therapy in the postacute phase of cervical artery dissection: the Italian Project on Stroke in Young Adults Cervical Artery Dissection.

OBJECTIVE: To explore the impact of antithrombotic therapy discontinuation in the postacute phase of cervical artery dissection (CeAD) on the mid-term outcome of these patients. METHODS: In a cohort of consecutive patients with first-ever CeAD, enrolled in the setting of the multicentre Italian Project on Stroke in Young Adults Cervical Artery Dissection, we compared postacute (beyond 6 months since the index CeAD) outcomes between patients who discontinued antithrombotic therapy and patients who continued taking antithrombotic agents during follow-up. Primary outcome was a composite of ischaemic stroke and transient ischaemic attack. Secondary outcomes were (1) Brain ischaemia ipsilateral to the dissected vessel and (2) Recurrent CeAD. Associations with the outcome of interest were assessed by the propensity score (PS) method. RESULTS: Of the 1390 patients whose data were available for the outcome analysis (median follow-up time in patients who did not experience outcome events, 36.0 months (25th-75th percentile, 62.0)), 201 (14.4%) discontinued antithrombotic treatment. Primary outcome occurred in 48 patients in the postacute phase of CeAD. In PS-matched samples (201 vs 201), the incidence of primary outcomes among patients taking antithrombotics was comparable with that among patients who discontinued antithrombotics during follow-up (5.0% vs 4.5%; p(log rank test)=0.526), and so was the incidence of the secondary outcomes ipsilateral brain ischaemia (4.5% vs 2.5%; p(log rank test)=0.132) and recurrent CeAD (1.0% vs 1.5%; p(log rank test)=0.798). CONCLUSIONS: Discontinuation of antithrombotic therapy in the postacute phase of CeAD does not appear to increase the risk of brain ischaemia during follow-up.

Impact of SARS-CoV-2 infection on acute intracerebral haemorrhage in northern Italy.

INTRODUCTION: Growing evidence has been published as to the impact of SARS-CoV-2 (Severe acute respiratory syndrome coronavirus 2) on cerebrovascular events over the last few months, with considerable attention paid to ischemic strokes. Conversely, little is known about the clinical course of intracerebral haemorrhage (ICH) and simultaneous SARS-CoV-2 infection. METHOD: The Italian Society of Hospital Neurosciences (SNO) promoted a multicentre, retrospective, observational study (SNO-COVID-19), involving 20 Neurological Departments in Northern Italy. Clinical data on patients with acute cerebrovascular diseases, admitted from March 1st to April 30th, 2020, were collected. A comparison was made of the demographical and clinical features of both SARS-CoV-2 positive and negative patients with ICH. RESULTS: 949 patients were enrolled (average age 73.4 years; 52.7% males); 135 patients had haemorrhagic stroke and 127 (13.4%) had a primary ICH. Only 16 patients with ICH (12.6%) had laboratory confirmed SARS-CoV-2 infection, both symptomatic and asymptomatic. SARS-CoV-2 related pneumonia or respiratory distress (OR 5.4), lobar location (OR 5.0) and previous antiplatelet or anticoagulant treatment (OR 2.9) were the only factors significantly associated with increased mortality in ICH. SARS-CoV-2 infection, regardless of respiratory involvement, led to a non-significantly increased risk of in-hospital death (37.5% vs 23.4%, p = 0.2). DISCUSSION: ICH patients with COVID-19 did not experience an increase in mortality as striking as ischemic stroke. The inflammatory response and respiratory complications could justify the slight increase of death in ICH. Bleeding sites and previous antiplatelet or anticoagulant treatment were the only other predictors of a worse outcome.

Clinical Features of Patients With Cervical Artery Dissection and Fibromuscular Dysplasia.

BACKGROUND AND PURPOSE: Observational studies have suggested a link between fibromuscular dysplasia and spontaneous cervical artery dissection (sCeAD). However, whether patients with coexistence of the two conditions have distinctive clinical characteristics has not been extensively investigated. METHODS: In a cohort of consecutive patients with first-ever sCeAD, enrolled in the setting of the multicenter IPSYS CeAD study (Italian Project on Stroke in Young Adults Cervical Artery Dissection) between January 2000 and June 2019, we compared demographic and clinical characteristics, risk factor profile, vascular pathology, and midterm outcome of patients with coexistent cerebrovascular fibromuscular dysplasia (cFMD; cFMD+) with those of patients without cFMD (cFMD-). RESULTS: A total of 1283 sCeAD patients (mean age, 47.8±11.4 years; women, 545 [42.5%]) qualified for the analysis, of whom 103 (8.0%) were diagnosed with cFMD+. In multivariable analysis, history of migraine (odds ratio, 1.78 [95% CI, 1.13-2.79]), the presence of intracranial aneurysms (odds ratio, 8.71 [95% CI, 4.06-18.68]), and the occurrence of minor traumas before the event (odds ratio, 0.48 [95% CI, 0.26-0.89]) were associated with cFMD. After a median follow-up of 34.0 months (25th to 75th percentile, 60.0), 39 (3.3%) patients had recurrent sCeAD events. cFMD+ and history of migraine predicted independently the risk of recurrent sCeAD (hazard ratio, 3.40 [95% CI, 1.58-7.31] and 2.07 [95% CI, 1.06-4.03], respectively) in multivariable Cox proportional hazards analysis. CONCLUSIONS: Risk factor profile of sCeAD patients with cFMD differs from that of patients without cFMD. cFMD and migraine are independent predictors of midterm risk of sCeAD recurrence.

Limb girdle muscular dystrophy due to LAMA2 gene mutations: new mutations expand the clinical spectrum of a still challenging diagnosis.

Mutations in LAMA2 gene, encoding merosin, are generally responsible of a severe congenital-onset muscular dystrophy (CMD type 1A) characterized by severe weakness, merosin absence at muscle analysis and white matter alterations at brain Magnetic Resonance Imaging (MRI). Recently, LAMA2 mutations have been acknowledged as responsible of LGMD R23, despite only few cases with slowly progressive adult-onset and partial merosin deficiency have been reported. We describe 5 independent Italian subjects presenting with progressive limb girdle muscular weakness, brain white matter abnormalities, merosin deficiency and LAMA2 gene mutations. We detected 7 different mutations, 6 of which are new. All patients showed normal psicomotor development and slowly progressive weakness with onset spanning from childhood to forties. Creatin-kinase levels were moderately elevated. One patient showed dilated cardiomyopathy. Muscle MRI allowed to evaluate the degree and pattern of muscular involvement in all patients. Brain MRI was fundamental in order to address and/or support the molecular diagnosis, showing typical widespread white matter hyperintensity in T2-weighted sequences. Interestingly these alterations were associated with central nervous system involvement in 3 patients who presented epilepsy and migraine. Muscle biopsy commonly but not necessarily revealed dystrophic features. Western-blot was usually more accurate than immunohystochemical analysis in detecting merosin deficiency. The description of these cases further enlarges the clinical spectrum of LAMA2-related disorders. Moreover, it supports the inclusion of LGMD R23 in the new classification of LGMD. The central nervous system involvement was fundamental to address the diagnosis and should be always included in the diagnostic work-up of undiagnosed LGMD.

The clinical spectrum of CASQ1-related myopathy.

OBJECTIVE: To identify and characterize patients with calsequestrin 1 (CASQ1)-related myopathy. METHODS: Patients selected according to histopathologic features underwent CASQ1 genetic screening. CASQ1-mutated patients were clinically evaluated and underwent muscle MRI. Vacuole morphology and vacuolated fiber type were characterized. RESULTS: Twenty-two CASQ1-mutated patients (12 families) were identified, 21 sharing the previously described founder mutation (p.Asp244Gly) and 1 with the p.Gly103Asp mutation. Patients usually presented in the sixth decade with exercise intolerance and myalgias and later developed mild to moderate, slowly progressive proximal weakness with quadriceps atrophy and scapular winging. Muscle MRI (n = 11) showed a recurrent fibrofatty substitution pattern. Three patients presented subclinical cardiac abnormalities. Muscle histopathology in patients with p.Asp244Gly showed vacuoles in type II fibers appearing empty in hematoxylin-eosin, Gomori, and nicotinamide adenine dinucleotide (NADH) tetrazolium reductase stains but strongly positive for sarcoplasmic reticulum proteins. The muscle histopathology of p.Gly103Asp mutation was different, showing also NADH-positive accumulation consistent with tubular aggregates. CONCLUSIONS: We report the clinical and molecular details of the largest cohort of CASQ1-mutated patients. A possible heart involvement is presented, further expanding the phenotype of the disease. One mutation is common due to a founder effect, but other mutations are possible. Because of a paucity of symptoms, it is likely that CASQ1 mutations may remain undiagnosed if a muscle biopsy is not performed.

Exertional rhabdomyolysis leading to acute kidney injury: when genetic defects are diagnosed in adult life.

Rhabdomyolysis is a common cause of acute kidney injury (AKI) that is usually triggered by trauma. However, less common causes of rhabdomyolysis may precipitate AKI as well, possibly representing a diagnostic challenge even for the experienced nephrologist. Genetic defects of muscle metabolism represent one of these causes and can be overlooked in adults, since these diseases usually become apparent in childhood. We present here a case in which an adult patient with severe exertional rhabdomyolysis leading to AKI was finally diagnosed with a genetic defect of lipid metabolism. A 41-year-old patient was brought to our attention because of AKI and pigmenturia after strenuous physical effort. At admission, the patient was over-hydrated with a weight increase of 3 kg in few days. Laboratory examination showed creatinine of 8.7 mg/dl, along with increased myoglobin and CPK. Urinalysis was positive for haemoglobin and proteins, while urinary sediment analysis did not demonstrate any red blood cell but rather "muddy-brown" casts and tubular cells. Urine output was forced and the patient completely recovered renal function. Genetic analysis later demonstrated the presence of a common mutation of Carnitine Palmitoyl-Transferase II (CPTII). When facing rhabdomyolysis of obscure origin, nephrologists must keep in mind the possibility that even adult patients may have a genetic defect of energy metabolism. In these cases, patients usually experience rhabdomyolysis during exertion, fasting, or infection. CPTII deficiency often has a subtle presentation and might be unrecognized until AKI develops. Therefore, it is important to consider a genetic defect of muscle metabolism even in adult patients when a history of rhabdomyolysis of unclear origin is present.

A case report with the peculiar concomitance of 2 different genetic syndromes.

RATIONALE: Down syndrome (DS) is the most common chromosome disorder in live born infants, affecting several body systems, but usually sparing skeletal muscles. We present the case of a child with coexistence of DS and dystrophinopathy. Only 1 similar case has been reported so far. PATIENT CONCERNS: An 8-year-old boy with DS had a history of incidental finding of increased serum creatine kinase levels up to 1775 U/L (normal values 38-174 U/L). He presented no delay in motor development; at the neurological examination, no muscle weakness or fatigability was detected in 2 different evaluations performed over a 6-month period. DIAGNOSES: Skeletal muscle biopsy revealed marked dystrophic changes with patchy immunostaining for dystrophin. The Duchenne muscular dystrophy gene was screened for deletions by multiplex polymerase chain reaction, but no mutations were found. Sequence analysis of the Duchenne muscular dystrophy gene revealed a splice-site mutation c.1812+1G>A in intron 15 and confirmed a diagnosis of Becker muscular dystrophy. INTERVENTIONS: The patient has started a specific physiotherapy that avoided any deterioration in motor development and muscular wasting. OUTCOMES: A multidisciplinary follow-up was initiated. The genetician that followed the patient for DS was supported by the neurologist, the physiotherapist, the pulmonologist, and the cardiologist. LESSONS: This peculiar "double trouble" case exemplifies the value of careful clinical evaluation and adequate clinical experience to identify the concomitance of 2 different genetic syndromes in the same patient, and it points out the significance of muscular strength assessment in DS patients to make the most correct prognosis, and, consequently, to organize the best long-term care.

New Mutations in NEB Gene Discovered by Targeted Next-Generation Sequencing in Nemaline Myopathy Italian Patients.

Nemaline myopathy represents a group of clinically and genetically heterogeneous neuromuscular disorders. Different clinical-genetic entities have been characterized in the last few years, with implications for diagnostics and genetic counseling. Fifty percent of nemaline myopathy forms are due to NEB mutations, but genetic analysis of this large and complex gene by Sanger sequencing is time consuming and expensive. We selected 10 Italian patients with clinical and biopsy features suggestive for nemaline myopathy and negative for ACTA1, TPM2 and TPM3 mutations. We applied a targeted next-generation sequencing strategy designed to analyse NEB coding regions, the relative full introns and the promoter. We also evaluated copy number variations (by CGH array) and transcriptional changes by RNA Sanger sequencing, whenever possible. This combined strategy revealed 11 likely pathogenic variants in 8 of 10 patients. The molecular diagnosis was fully achieved in 3 of 8 patients, while only one heterozygous mutation was observed in 5 subjects. This approach revealed to be a fast and cost-effective way to analyse the large NEB gene in a small group of patients and might be promising for the detection of pathological variants of other genes featuring large coding regions and lacking mutational hotspots.

Coexistence of VHL Disease and CPT2 Deficiency: A Case Report.

von Hippel-Lindau (VHL) disease is an inherited syndrome manifesting with benign and malignant tumors. Deficiency of carnitine palmitoyltransferase type II (CPT2) is a disorder of lipid metabolism that, in the muscle form, manifests with recurrent attacks of myalgias often associated with myoglobinuria. Rhabdomyolytic episodes may be complicated by life-threatening events, including acute renal failure (ARF). We report on a male patient who was tested, at 10 years of age, for VHL disease because of family history of VHL. He was diagnosed with VHL but without VHL-related manifestation at the time of diagnosis. During childhood, the patient was hospitalized several times for diffuse muscular pain, muscle weakness, and dark urine. These recurrent attacks of rhabdomyolysis were never accompanied by ARF. The patient was found to be homozygous for the mutation p.S113L of the CPT2 gene. To the best of our knowledge, this is the first report of the coexistence of VHL disease and CPT2 deficiency in the same individual. Based on findings from animal models, the case illustrates that mutations in the VHL gene might protect against renal damage caused by CPT2 gene mutations.

ISPD mutations account for a small proportion of Italian Limb Girdle Muscular Dystrophy cases.

BACKGROUND: Limb Girdle Muscular Dystrophy (LGMD), caused by defective α-dystroglycan (α-DG) glycosylation, was recently associated with mutations in Isoprenoid synthase domain-containing (ISPD) and GDP-mannose pyrophosphorylase B (GMPPB) genes. The frequency of ISPD and GMPPB gene mutations in the LGMD population is unknown. METHODS: We investigated the contributions of ISPD and GMPPB genes in a cohort of 174 Italian patients with LGMD, including 140 independent probands. Forty-one patients (39 probands) from this cohort had not been genetically diagnosed. The contributions of ISPD and GMPPB were estimated by sequential α-DG immunohistochemistry (IHC) and mutation screening in patients with documented α-DG defect, or by direct DNA sequencing of both genes when muscle tissue was unavailable. RESULTS: We performed α-DG IHC in 27/39 undiagnosed probands: 24 subjects had normal α-DG expression, two had a partial deficiency, and one exhibited a complete absence of signal. Direct sequencing of ISPD and GMPPB revealed two heterozygous ISPD mutations in the individual who lacked α-DG IHC signal: c.836-5 T > G (which led to the deletion of exon 6 and the production of an out-of-frame transcript) and c.676 T > C (p.Tyr226His). This patient presented with sural hypertrophy and tip-toed walking at 5 years, developed moderate proximal weakness, and was fully ambulant at 42 years. The remaining 12/39 probands did not exhibit pathogenic sequence variation in either gene. CONCLUSION: ISPD mutations are a rare cause of LGMD in the Italian population, accounting for less than 1% of the entire cohort studied (FKRP mutations represent 10%), while GMPPB mutations are notably absent in this patient sample. These data suggest that the genetic heterogeneity of LGMD with and without α-DG defects is greater than previously realized.

Centronuclear myopathies: genotype-phenotype correlation and frequency of defined genetic forms in an Italian cohort.

Centronuclear myopathies (CNMs) are a group of clinically and genetically heterogeneous muscle disorders. To date, mutation in 7 different genes has been reported to cause CNMs but 30 % of cases still remain genetically undefined. Genetic investigations are often expensive and time consuming. Clinical and morphological clues are needed to facilitate genetic tests and to choose the best approach for genetic screening. We aimed to describe genotype-phenotype correlation in an Italian cohort of patients affected by CNMs, to define the relative frequencies of its defined genetic forms and to draw a diagnostic algorithm to address genetic investigations. We recruited patients with CNMs from all the Italian tertiary neuromuscular centers following clinical and histological criteria. All selected patients were screened for the four 'canonical' genes related to CNMs: MTM1, DNM2, RYR1 and BIN1. Pathogenetic mutations were found in 38 of the 54 screened patients (70 %), mostly in patients with congenital onset (25 of 30 patients, 83 %): 15 in MTM1, 6 in DNM2, 3 in RYR1 and one in TTN. Among the 13 patients with a childhood-adolescence onset, mutations were found in 6 patients (46 %), all in DNM2. In the group of the 11 patients with adult onset, mutations were identified in 7 patients (63 %), again in DNM2, confirming that variants in this gene are relatively more common in late-onset phenotypes. The present study provides the relative molecular frequency of centronuclear myopathy and of its genetically defined forms in Italy and also proposes a diagnostic algorithm to be used in clinical practice to address genetic investigations.

Impaired Muscle Mitochondrial Biogenesis and Myogenesis in Spinal Muscular Atrophy.

IMPORTANCE: The important depletion of mitochondrial DNA (mtDNA) and the general depression of mitochondrial respiratory chain complex levels (including complex II) have been confirmed, implying an increasing paucity of mitochondria in the muscle from patients with types I, II, and III spinal muscular atrophy (SMA-I, -II, and -III, respectively). OBJECTIVE: To investigate mitochondrial dysfunction in a large series of muscle biopsy samples from patients with SMA. DESIGN, SETTING, AND PARTICIPANTS: We studied quadriceps muscle samples from 24 patients with genetically documented SMA and paraspinal muscle samples from 3 patients with SMA-II undergoing surgery for scoliosis correction. Postmortem muscle samples were obtained from 1 additional patient. Age-matched controls consisted of muscle biopsy specimens from healthy children aged 1 to 3 years who had undergone analysis for suspected myopathy. Analyses were performed at the Neuromuscular Unit, Istituto di Ricovero e Cura a Carattere Scientifico Foundation Ca' Granda Ospedale Maggiore Policlinico-Milano, from April 2011 through January 2015. EXPOSURES: We used histochemical, biochemical, and molecular techniques to examine the muscle samples. MAIN OUTCOMES AND MEASURES: Respiratory chain activity and mitochondrial content. RESULTS: Results of histochemical analysis revealed that cytochrome-c oxidase (COX) deficiency was more evident in muscle samples from patients with SMA-I and SMA-II. Residual activities for complexes I, II, and IV in muscles from patients with SMA-I were 41%, 27%, and 30%, respectively, compared with control samples (P < .005). Muscle mtDNA content and cytrate synthase activity were also reduced in all 3 SMA types (P < .05). We linked these alterations to downregulation of peroxisome proliferator-activated receptor coactivator 1α, the transcriptional activators nuclear respiratory factor 1 and nuclear respiratory factor 2, mitochondrial transcription factor A, and their downstream targets, implying depression of the entire mitochondrial biogenesis. Results of Western blot analysis confirmed the reduced levels of the respiratory chain subunits that included mitochondrially encoded COX1 (47.5%; P = .004), COX2 (32.4%; P < .001), COX4 (26.6%; P < .001), and succinate dehydrogenase complex subunit A (65.8%; P = .03) as well as the structural outer membrane mitochondrial porin (33.1%; P < .001). Conversely, the levels of expression of 3 myogenic regulatory factors-muscle-specific myogenic factor 5, myoblast determination 1, and myogenin-were higher in muscles from patients with SMA compared with muscles from age-matched controls (P < .05). CONCLUSIONS AND RELEVANCE: Our results strongly support the conclusion that an altered regulation of myogenesis and a downregulated mitochondrial biogenesis contribute to pathologic change in the muscle of patients with SMA. Therapeutic strategies should aim at counteracting these changes.

Congenital myopathies: Natural history of a large pediatric cohort.

OBJECTIVE: To assess the natural history of congenital myopathies (CMs) due to different genotypes. METHODS: Retrospective cross-sectional study based on case-note review of 125 patients affected by CM, followed at a single pediatric neuromuscular center, between 1984 and 2012. RESULTS: Genetic characterization was achieved in 99 of 125 cases (79.2%), with RYR1 most frequently implicated (44/125). Neonatal/infantile onset was observed in 76%. At birth, 30.4% required respiratory support, and 25.2% nasogastric feeding. Twelve percent died, mainly within the first year, associated with mutations in ACTA1, MTM1, or KLHL40. All RYR1-mutated cases survived and did not require long-term ventilator support including those with severe neonatal onset; however, recessive cases were more likely to require gastrostomy insertion (p = 0.0028) compared with dominant cases. Independent ambulation was achieved in 74.1% of all patients; 62.9% were late walkers. Among ambulant patients, 9% eventually became wheelchair-dependent. Scoliosis of variable severity was reported in 40%, with 1/3 of (both ambulant and nonambulant) patients requiring surgery. Bulbar involvement was present in 46.4% and required gastrostomy placement in 28.8% (at a mean age of 2.7 years). Respiratory impairment of variable severity was a feature in 64.1%; approximately half of these patients required nocturnal noninvasive ventilation due to respiratory failure (at a mean age of 8.5 years). CONCLUSIONS: We describe the long-term outcome of a large cohort of patients with CMs. While overall course is stable, we demonstrate a wide clinical spectrum with motor deterioration in a subset of cases. Severity in the neonatal/infantile period is critical for survival, with clear genotype-phenotype correlations that may inform future counseling.

Mitochondrial disease heterogeneity: a prognostic challenge.

Mitochondrial diseases are a heterogeneous group of progressive, genetically transmitted, multisystem disorders caused by impaired mitochondrial function. The disease course for individuals with mitochondrial myopathies varies greatly from patient to patient because disease progression largely depends on the type of disease and on the degree of involvement of various organs which makes the prognosis unpredictable both within the same family and among families with the same mutation. This is particularly, but not exclusively, true for mitochondrial disorders caused by mtDNA point mutations, which are maternally inherited and subject to the randomness of the heteroplasmy. For this reason, the prognosis cannot be given by single mitochondrial disease, but should be formulated by any single mitochondrial disease-related event or complication keeping in mind that early recognition and treatment of symptoms are crucial for the prognosis. The following approach can help prevent severe organ dysfunctions or at least allow early diagnosis and treatment of disease-related complications.

Optic atrophy plus phenotype due to mutations in the OPA1 gene: two more Italian families.

Autosomal Dominant Optic Atrophy (ADOA) is characterized by the selective degeneration of retinal ganglion cells. The occurrence of mutations in the gene encoding the dynamin-like GTPase protein Optic Atrophy 1 (OPA1) has been observed in about 60-70% of ADOA cases. A subset of missense mutations, mostly within the GTPase domain, has recently been associated with a syndromic ADOA form called "OPA1 plus" phenotype presenting, at muscle level, mitochondrial DNA (mtDNA) instability. In this study we disclosed two OPA1 gene mutations in independent probands from two families affected by OPA1 plus phenotype: the previously reported c.985-2A>G substitution and a novel microdeletion (c.2819-1_2821del). The correlation between genotype and phenotype and the effects of these variants at the transcript level and in the muscle tissue were investigated, confirming the broad complexity in the phenotypic spectrum associated with these OPA1 mutations.

Two novel mutations in PEO1 (twinkle) gene associated with chronic external ophthalmoplegia.

Maintenance and replication of mitochondrial DNA require the concerted action of several factors encoded by nuclear genome. The mitochondrial helicase Twinkle is a key player of replisome machinery. Heterozygous mutations in its coding gene, PEO1, are associated with progressive external ophthalmoplegia (PEO) characterised by ptosis and ophthalmoparesis, with cytochrome c oxidase (COX)-deficient fibres, ragged-red fibres (RRF) and multiple mtDNA deletions in muscle. Here we describe clinical, histological and molecular features of two patients presenting with mitochondrial myopathy associated with PEO. PEO1 sequencing disclosed two novel mutations in exons 1 and 4 of the gene, respectively. Although mutations in PEO1 exon 1 have already been described, this is the first report of mutation occurring in exon 4.