Exophthalmos associated with chronic progressive external ophthalmoplegia.

PURPOSE: Chronic progressive external ophthalmoplegia (CPEO) is a mitochondrial disease characterized by slowly progressive ptosis and limitations in ocular motility. Although exophthalmos is not considered to be a common feature of CPEO, this study focused on the incidence of exophthalmos in patients with CPEO. STUDY DESIGN: Retrospective observational case series METHODS: We reviewed the clinical charts of patients who received a diagnosis of CPEO sometime during the period between January 2010 and December 2018. CPEO was diagnosed on the basis of detection of a deletion of mitochondrial DNA (mtDNA) from saliva, buccal mucosa, or extraocular muscle specimens obtained during strabismus surgery. Horizontal MRI/CT images or Hertel ophthalmometry was used in determining exophthalmos. RESULTS: Seven patients (4 males) were identified. The mean age at diagnosis was 32.6 years (range 13-53 years). mtDNA deletion mutations were detected in the buccal mucous membrane DNA in 5 patients and in the saliva and extraocular muscle DNA in 2 patients. MRI/CT was recorded in 6 patients, four of whom showed exophthalmos (cases 1-4), and case 5 was determined as exophthalmos on the basis of a Hertel ophthalmometer reading. Exophthalmos was bilateral in 4 of the patients (cases 1, 2, 4, and 5) and unilateral in 1 patient (case 3). Exophthalmos was the chief concern of 2 of the patients; however, it was not clinically significant in the other patients. CONCLUSIONS: Although exophthalmos may not be recognized by either the patient or the clinician, it may be one of the common features of CPEO. A large multiethnic study should be performed.

A novel homozygous frameshift mutation in the DCC gene in a Pakistani family with autosomal recessive horizontal gaze palsy with progressive scoliosis-2 with impaired intellectual development.

Horizontal Gaze Palsy with Progressive Scoliosis-2 with Impaired Intellectual Development (HGPPS2) is a rare congenital disorder characterized by absence of conjugate horizontal eye movements, and progressive scoliosis developing in childhood and adolescence. We report three new patients with HGPPS2 in a consanguineous Pakistani family, presenting varying degrees of progressive scoliosis, developmental delays, horizontal gaze palsy, agenesis of corpus callosum, and absence of cerebral commissures. Analysis of genotyping data identified shared loss of heterozygosity (LOH) region on chromosomes 5p15.33-15.31, 6q11.2-12, and 18q21.1-21.3. A hypothesis-free, unbiased exome data analysis detected an insertion of nucleotide A (c.2399dupA) in exon 16 of the DCC gene. The insertion is predicted to cause frameshift p.(Asn800Lysfs*11). Interestingly, DCC gene is present in the LOH region on chromosome 18. Variant (c.2399dupA) in the DCC gene is considered as the most probable candidate variant for HGPPS2 based on the presence of DCC in the LOH region, previously reported role of DCC in HGPPS2, perfect segregation of candidate variant with the disease, prediction of variant pathogenicity, and absence of variant in variation databases. Sanger Sequencing confirmed the presence of the novel homozygous mutation in all three patients; the parents were heterozygous carriers of the mutation, in accordance with an autosomal recessive inheritance pattern. DCC encodes a netrin-1 receptor protein; its role in the development of the CNS has recently been established. Biallelic DCC mutations have previously been shown to cause HGPPS2. A novel homozygous variant in patients of the reported family extend the genotypic and phenotypic spectrum of HGPPS2.

Strabismus surgery for diplopia in chronic progressive external ophthalmoplegia.

BACKGROUND: To report midterm outcomes of strabismus strategy for management of diplopia in chronic progressive external ophthalmoplegia and specific surgical planning rationale. DESIGN: Retrospective interventional case series. RESULTS: Two patients, a 26-year-old male and a 36-year-old female, diagnosed with chronic progressive external ophthalmoplegia presented with blepharoptosis and intermittent diplopia. Ocular motility examination was significant for bilateral profound impairment of adduction with relative preservation of abduction, infraduction and elevation. Control of intermittent exotropia gradually worsened over 3 and 1.5 years of follow-up, respectively, in the presence of documented stability of the angle of exodeviation. Strabismus surgery involving modest amounts of bilateral medial rectus resection and lateral rectus recessions was undertaken. Surgical intervention was successful in controlling alignment in primary position and alleviating diplopia and asthenopia after 9 and 8 years of follow-up time, respectively, despite slow progression of ophthalmoplegia. CONCLUSION: Bilateral selective impairment of adduction and intermittent exotropia may be the presenting ocular motility disturbance in chronic progressive external ophthalmoplegia. Properly designed strabismus surgery may provide sustainable, in the midterm, control of alignment and symptomatic relief in selected patients with CPEO.

Focal Segmental Glomerulosclerosis Associated with Chronic Progressive External Ophthalmoplegia and Mitochondrial DNA A3243G Mutation.

Focal segmental glomerulosclerosis (FSGS) is caused by various etiologies, with mitochondrial dysfunction being one of the causes. FSGS is known to be associated with mitochondrial encephalomyopathy, lactic acidosis, and stroke-like episodes (MELAS), which is a subclass of mitochondrial disease. However, it has rarely been reported in other mitochondrial disease subclasses. Here, we reported a 20-year-old man diagnosed with FSGS associated with chronic progressive external ophthalmoplegia (CPEO) due to mitochondrial DNA (mtDNA) 3243A>G mutation. He presented with left ptosis, short stature, mild sensorineural deafness, and cardiac conduction block. A renal biopsy sample showed segmental sclerosis and adhesions between capillaries and Bowman's capsule, indicating FSGS. Electron microscopy demonstrated abnormal aggregated mitochondria in podocytes, and the basement membrane and epithelial cells of Bowman's capsule. Skeletal muscle biopsy also showed accumulation of abnormal mitochondria. mtDNA analysis identified heteroplasmic mtDNA 3243A>G mutation with no large-scale deletions. From these findings, we diagnosed the case as CPEO with multi-organ involvement including FSGS. Our report demonstrates that CPEO, as well as MELAS, can be associated with FSGS. Because mitochondrial disease presents with a variety of clinical symptoms, atypical cases with non-classical manifestations are observed. Thus, mitochondrial disease should be considered as an underlying cause of FSGS with systemic manifestations even with atypical phenotypes.

Surgical Technique for Pulled in Two Syndrome: Three Cases With Chronic Progressive External Ophthalmoplegia.

The authors describe three examples of "pulled in two syndrome" (PITS) from a series of 13 patients undergoing strabismus surgery with underlying chronic progressive external ophthalmoplegia (CPEO) and illustrate techniques for recovery of the "pulled in two" extraocular muscle should the complication arise. In all cases, a rectus muscle snapped under minimal tension while held on a strabismus hook during strabismus surgery. Two patients suffered from CPEO as a result of genetic mitochondrial disease, whereas one resulted from presumed mitochondrial toxicity induced by HAART. In cases 1 and 3, the proximal medial rectus segment was retrieved and reattached. In case 2, the fragmented superior rectus muscle was too friable to be reattached. All three patients were satisfied with the outcome, having reduced their angles of misalignment postoperatively. All three had improved cosmesis, and the two who had complained of diplopia preoperatively found their diplopia to be eliminated or improved. With anticipation of muscle friability in patients with previous extraocular surgery or degenerative muscle changes such as CPEO, the likelihood of the complication arising may be reduced. Should it occur, the loss of a snapped rectus muscle may be avoided through careful manipulation of the globe. [J Pediatr Ophthalmol Strabismus. 2017;54:e83-e87.].

Chronic Progressive External Ophthalmoplegia in the Absence of Ptosis.

Classically defined as bilateral, symmetric, and progressive ophthalmoparesis with myopathic ptosis, chronic progressive external ophthalmoplegia (CPEO) rarely has been reported in the absence of ptosis. We describe 2 patients with CPEO and without ptosis who presented with binocular diplopia related to small-angle esodeviations, poor fusional amplitudes, and slow saccades. In both cases, hematological studies and neuroimaging ruled out alternative etiologies, whereas muscle biopsy showed findings of mitochondrial myopathy.

Syndromic parkinsonism and dementia associated with OPA1 missense mutations.

OBJECTIVE: Mounting evidence links neurodegenerative disorders such as Parkinson disease and Alzheimer disease with mitochondrial dysfunction, and recent emphasis has focused on mitochondrial dynamics and quality control. Mitochondrial dynamics and mtDNA maintenance is another link recently emerged, implicating mutations in the mitochondrial fusion genes OPA1 and MFN2 in the pathogenesis of multisystem syndromes characterized by neurodegeneration and accumulation of mtDNA multiple deletions in postmitotic tissues. Here, we report 2 Italian families affected by dominant chronic progressive external ophthalmoplegia (CPEO) complicated by parkinsonism and dementia. METHODS: Patients were extensively studied by optical coherence tomography (OCT) to assess retinal nerve fibers, and underwent muscle and brain magnetic resonance spectroscopy (MRS), and muscle biopsy and fibroblasts were analyzed. Candidate genes were sequenced, and mtDNA was analyzed for rearrangements. RESULTS: Affected individuals displayed a slowly progressive syndrome characterized by CPEO, mitochondrial myopathy, sensorineural deafness, peripheral neuropathy, parkinsonism, and/or cognitive impairment, in most cases without visual complains, but with subclinical loss of retinal nerve fibers at OCT. Muscle biopsies showed cytochrome c oxidase-negative fibers and mtDNA multiple deletions, and MRS displayed defective oxidative metabolism in muscle and brain. We found 2 heterozygous OPA1 missense mutations affecting highly conserved amino acid positions (p.G488R, p.A495V) in the guanosine triphosphatase domain, each segregating with affected individuals. Fibroblast studies showed a reduced amount of OPA1 protein with normal mRNA expression, fragmented mitochondria, impaired bioenergetics, increased autophagy and mitophagy. INTERPRETATION: The association of CPEO and parkinsonism/dementia with subclinical optic neuropathy widens the phenotypic spectrum of OPA1 mutations, highlighting the association of defective mitochondrial dynamics, mtDNA multiple deletions, and altered mitophagy with parkinsonism.

Chronic progressive external ophthalmoplegia with inflammatory myopathy.

Chronic progressive external ophthalmoplegia is one of mitochondrial disorders, characterized by ptosis, limitation of eye movement, variably severe bulbar muscle weakness and proximal limb weakness. Chronic progressive external ophthalmoplegia complicated with acquired disease is extremely rare. We report a 44 years old male patient with more than 20 years of chronic progressive bilateral ptosis and limitation of eye movements manifested dysarthria, dysphagia and neck muscle weakness for 3 years. The first muscle biopsy showed red-ragged fibers and cytochrome c oxidase negative fibers as well as inflammatory cells infiltration. Electron microscopy revealed paracrystalline inclusions. Mitochondrial genetic analysis demonstrated a large-scale mtDNA deletion of m.8470_13446del4977. The patient was treated with prednisone. In a three-year follow-up study, the second biopsy was performed. Before the treatment, except bilateral ptosis and external ophthalmopelgia, this patient presented bulbar muscle weakness and neck muscle weakness. After treated with prednisone, the symptoms of dysphagia, dysarthria and neck muscle weakness were significantly improved, and the second biopsy showed only mitochondrial myopathy pathology but the inflammations disappeared. Here, we report a patient with chronic progressive external ophthalmoplegia complicated with inflammatory myopathy and after treated with prednisone as myositis, he had a significant therapeutic effect.

Twinkle mutation in an Italian family with external progressive ophthalmoplegia and parkinsonism: a case report and an update on the state of art.

The objective is to describe the clinical phenotype and genetic basis of a family with autosomal dominant progressive external ophthalmoplegia and parkinsonism with a Twinkle mutation. The proband, an 82 years old female, reported since childhood bilateral eyelid ptosis, ophthalmoplegia, sensorineural hypoacusis, mild depression since she was 45, with a positive familiar anamnesis of eyelid ptosis (father, two sisters and a son). She developed mild bilateral parkinsonism with a moderate clinical response to levodopa. The (123)I-FP-CIT SCAN evidenced a marked bilateral putaminal reduction and moderate caudate uptake reduction. Her 79 years old sister reported eyelid ptosis since she was 45 with ophthalmoplegia and developed a mild bilateral rest and postural tremor with moderate right arm plastic hypertonia when she was 76. The parkinsonism was confirmed with (123)I-FP-CIT SCAN. One of the two sons presented eyelid ptosis since he was 30 years old, with peripheral neuropathy with biopsy evidence of myopathy. We identified a G1750A mutation in the c10orf2 gene in the three patients. Mitochondrial dysfunction has been implicated in the pathogenesis of sporadic, idiopathic Parkinson disease (PD). In some cases, mitochondrial DNA primary genetic abnormalities or more commonly secondary rearrangements due to polymerase gamma (POLG) gene mutation can directly cause parkinsonism. Parkinsonism has been reported as a rare symptom associated to Twinkle (c10orf2). Parkinsonism has to be investigated in patients with PEO with analysis of Twinkle mutation.

Orthostatic tremor, progressive external ophthalmoplegia, and Twinkle.

IMPORTANCE: Orthostatic tremor (OT) is a high-frequency (13-18 Hz) leg tremor occurring in standing position. Orthostatic tremor has an unknown pathophysiologic mechanism. It is thought to be sporadic but siblings with OT from 3 unrelated families were reported. No mutations have been reported in OT. We describe a patient with OT carrying a C10orf2 TWINKLE mutation to highlight the possible association of OT with mitochondrial dysfunction and mutations in the mitochondrial replicative helicase Twinkle. OBSERVATIONS: A man in his late 60s had ptosis and tremor on standing for 30 years, followed by development of progressive external ophthalmoplegia. Polygraphic recordings revealed an orthostatic synchronic tremor with 17.5-Hz frequency. Electromyography/nerve conduction studies showed evidence for a mild myopathy and associated mild axonal sensorimotor peripheral neuropathy. Muscle biopsy revealed ragged red fibers; mild cerebral atrophy was evident by magnetic resonance imaging. Molecular analysis revealed a novel heterozygous missense mutation at an evolutionarily conserved residue of the C10orf2 TWINKLE gene. CONCLUSIONS AND RELEVANCE: Although the incidental association of OT and C10orf2 TWINKLE mutation is possible, the simultaneous onset of OT and eyelid ptosis at a much younger age than usually observed for OT raises the possibility of mitochondrial dysfunction and loss of mitochondrial DNA integrity in the pathogenesis of OT.

Eyelid surgery in ocular myopathies.

OBJECTIVE: To retrospectively analyse surgical outcome and complications in patients with ocular myopathy undergoing ptosis correction and to introduce preoperative prophylactic lower lid elevation in this group. METHODS: The medical records of all ocular myopathy patients who had undergone oculoplastic surgery between June 1995 and May 2006 were obtained. Patients' demographics, surgical details and measurements, and complications were recorded. RESULTS: 29 patients were identified; 21 with chronic progressive external ophthalmoplegia (CPEO), 7 with myotonic dystrophy (MD) and 1 with oculopharyngeal muscular dystrophy (OPMD). Then, 61 procedures to adjust eyelid height were performed, comprising levator resection, brow suspension, anterior lamellar repositioning, lower lid elevation and upper lid lowering. Palpebral aperture was significantly increased in all patient groups, by procedure and diagnosis, more significantly following brow suspension compared with levator resection. The patients' feedback was very positive. Post-operative complications were few, included corneal exposure and ulceration, ptosis recurrence, arched brow, and sling infection, all of which were successfully treated. CONCLUSION: Our results demonstrate subjective and objective benefit following surgery in these patients, with a low complication rate. The use of pre-operative prophylactic lower lid elevation procedures is a promising modality.

[A clinical test for diagnosis of myasthenic ptosis].

A clinical test for diagnosis of ptosis in myasthenia is described. We studied the effect of antiorthostatic posture with head-down position on the degree of ptosis in myasthenia, ocular myopathy of von Graefe, lesions of the oculomotor nerve and pseudoptosis. The antiorthostatic posture significantly (p<0,05) decreased the degree of ptosis only in patients with myasthenia The degree of ptosis remained unchanged in myopathy of von Graefe, lesions of the oculomotor nerve and pseudoptosis.

Cardiac screening investigations in adult-onset progressive external ophthalmoplegia patients.

INTRODUCTION: Patients with mitochondrial myopathies may develop cardiac complications such as cardiomyopathy and/or cardiac conduction defects. To identify these potentially life-threatening and treatable conditions, it is common practice to screen patients intermittently with electrocardiography and echocardiography. The optimal time interval for such screening investigations is unknown. We developed this study to review our screening results in adult-onset patients with progressive external ophthalmoplegia (PEO). METHODS: This study was a retrospective review of PEO patients with 5 years or more of cardiac screening investigations who did not have any cardiac symptoms. RESULTS: Fifteen patients were included, and cardiomyopathy was identified on screening echocardiogram in 1 patient. Four patients had other abnormalities identified, which were unrelated to their mitochondrial myopathy. CONCLUSIONS: Only 1 patient in 15 developed cardiac complications related to mitochondrial disease during 5 years of follow-up. We suggest that a screening interval of 3-5 years is probably appropriate for adult-onset PEO patients who do not have cardiac symptoms.

A novel mitochondrial DNA deletion producing progressive external ophthalmoplegia associated with multiple sclerosis.

We report a previously undescribed 7676 base pair mitochondrial (mt)DNA deletion involving genes of complex I, complex IV subunits 2 and 3 (cytochrome oxidase [Cox] II, III), adenosine triphosphatase 8 and 6, cytochrome b and 8 transfer (t)RNA genes producing myopathy and progressive external ophthalmoplegia (PEO) in a 44-year-old right-handed Caucasian man with features of multiple sclerosis (MS). We performed complete mtDNA sequencing and deletion analysis, spectrophotometric analysis of muscle and platelet respiratory chain activity, measurement of platelet mitochondrial membrane potential with the potentiometric dye JC-1 and magnetic resonance spectroscopy (MRS) and MRI studies of normal-appearing and lesional cerebral tissue. The deletion resulted in significant respiratory chain deficiency in muscle and blood and abnormalities of the platelet mitochondrial membrane potential. However, cerebrospinal fluid analysis, magnetic resonance spectroscopy and MRI features suggested inflammatory central nervous system demyelination rather than a primary respiratory chain disorder. We conclude that this novel mtDNA deletion causing myopathy and PEO is associated with severe muscle and platelet cellular energetic abnormalities. Furthermore, clinical and paraclinical features of multiple sclerosis were found. The potential pathomechanistic interaction between mtDNA variation and multiple sclerosis is reviewed.

Genetic analysis of two Japanese families with progressive external ophthalmoplegia and parkinsonism.

Mutations in the progressive external ophthalmoplegia 1 (PEO1), adenine nucleotide translocator 1 (ANT1) and DNA polymerase gamma (POLG) genes were reported in patients with progressive external ophthalmoplegia and parkinsonism. However, the genotype-phenotype correlation and pathophysiology of these syndromes are still unknown. In order to define the molecular basis of progressive external ophthalmoplegia and parkinsonism, we screened for mutations in PEO1, ANT1, POLG genes and the whole mitochondrial genome in two families. In results, we identified a compound heterozygous POLG substitutions, c.830A>T (p.H277L) and c.2827C>T (p.R943C) in one of the families. These two mutations in the coding region of POLG alter conserved amino acids in the exonuclease and polymerase domains, respectively, of the POLG protein. Neither of these substitutions was found in the 100 chromosomes of ethnically matched control subjects. In the other family, no mutations were detected in any of the three genes and the whole mitochondrial genome in the blood sample, although mitochondrial DNA deletions were observed in the muscle biopsy sample. Progressive external ophthalmoplegia and parkinsonism are genetically heterogenous disorders, and part of this syndrome may be caused by mutations in other, unknown genes.

Multisystem disorder in late-onset chronic progressive external ophthalmoplegia.

INTRODUCTION: Chronic progressive external ophthalmoplegia (CPEO) is a mitochondrial syndrome on a disease spectrum with Kearns-Sayre syndrome (KSS). Clinical presentation is variable and our experience suggested that phenotypic differences exist in CPEO with onset after age 20. METHODS: This descriptive study is a retrospective chart review of 40 patients with late-onset CPEO. Clinical features, laboratory and neurophysiology results were reviewed. RESULTS: Multisystem dysfunction was very common in this series. Gastrointestinal dysfunction was more common than expected (60%) as was migraine headache (40%). Clinical characteristics on the KSS disease spectrum were uncommon in this series with only 2.5% having pigmentary retinopathy, 5% with cardiac conduction abnormality, and 22.5% having endocrinopathy (most often thyroid dysfunction rather than diabetes). Neurophysiology abnormalities included length-dependent axonal polyneuropathy in 44% (sometimes subclinical) and myopathic EMG changes in 26%. Exposure to sources of acquired mitochondrial toxicity including cigarette use and hepatitis C infection were more common than expected in this series. DISCUSSION: Phenotype was different in this late-onset series compared with previous reports in CPEO patients. In this series of late-onset patients, multi-organ dysfunction was more common than previously reported in CPEO, and some classical mitochondrial manifestations, such as pigmentary retinopathy were rare. We suggest that acquired mitochondrial toxicity may have a role in the pathogenesis of adult-onset CPEO.

A novel mitochondrial tRNA(Ile) point mutation associated with chronic progressive external ophthalmoplegia and hyperCKemia.

We have sequenced the entire mitochondrial DNA (mtDNA) from a 54-year-old man with chronic progressive external ophthalmoplegia (PEO) and hyperCKemia. Muscle biopsy showed ragged red and SDH positive/COX negative fibres, and the biochemistry was suggestive mitochondrial respiratory chain dysfunction. Analysis of mtDNA revealed a heteroplasmic m. 4308G>A mutation in the transfer RNA isoleucine gene (MT-TI gene). Our report expands the genetic heterogeneity of PEO.