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.

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.

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.