scholarly journals Mitochondrial diseases caused by mutations of the POLG gene: problems of differential diagnosis

2019 ◽  
pp. 58-66
Author(s):  
Y.G. Antipkin ◽  
◽  
L.G. Kirilova ◽  
A.A. Miroshnikov ◽  
A.A. Yuzva ◽  
...  
2015 ◽  
Vol 23 (1) ◽  
pp. 69-74
Author(s):  
Martyna Domańska ◽  
Emilia J. Sitek ◽  
Michał Schinwelski ◽  
Maria Mazurkiewicz-Bełdzińska ◽  
Agnieszka Matheisel ◽  
...  

SUMMARY Introduction. Myoclonic epilepsy with ragged red fibers (MERRF) is a rare, progressive mitochondrial disease affecting multiple systems, including the central nervous system. Typical MERRF symptoms include: myoclonus, epileptic seizures, ataxia and cognitive decline. In mitochondrial diseases selective cognitive impairment or generalized decline, called mitochondrial dementia, is usually diagnosed. Description of case. We present the case of an 18-year-old patient with progressive neurological symptoms such as multifocal myoclonus, cerebellar syndrome (gait impairment, intention tremor, ataxia and dysmetria). The diagnosis of MERRF was confirmed at the age of 16. Neuropsychological examination showed slowing of verbal learning and deficient spontaneous recall with improvement on recognition as well as low verbal fluency. Discussion. The authors discuss differential diagnosis of mitochondrial diseases (MIDs) in respect to cognitive function impairment and, in particular, to dementia: MELAS (mitochondrial myopathy, encephalopathy, lactic acidosis and stroke-like episodes), KSS (Kearns-Sayre syndrome), NARP syndrome (neuropathy, ataxia, and retinitis pigmentosa and ptosis). The authors emphasize importance of comprehensive neuropsychological assessment in differential diagnosis of MIDs. Conclusion. Mild and selective cognitive impairment was identified. The type and degree of cognitive function impairment is not sufficient to diagnose dementia in this particular case of MERRF. Comprehensive neuropsychological assessment is crucial in MID in order to provide the patient with useful recommendations for education planning.


2021 ◽  
Vol 12 ◽  
Author(s):  
Xuejun Ouyang ◽  
Yu Zhang ◽  
Lijuan Zhang ◽  
Jixuan Luo ◽  
Ting Zhang ◽  
...  

Genetic disorders are a frequent cause of hospitalization, morbidity and mortality in pediatric patients, especially in the neonatal or pediatric intensive care unit (NICU/PICU). In recent years, rapid genome-wide sequencing (exome or whole genome sequencing) has been applied in the NICU/PICU. However, mtDNA sequencing is not routinely available in rapid genetic diagnosis programs, which may fail to diagnose mtDNA mutation-associated diseases. Herein, we explored the clinical utility of rapid exome sequencing combined with mtDNA sequencing in critically ill pediatric patients with suspected genetic disorders. Rapid clinical exome sequencing (CES) was performed as a first-tier test in 40 critically ill pediatric patients (aged from 6 days to 15 years) with suspected genetic conditions. Blood samples were also collected from the parents for trio analysis. Twenty-six patients presented with neuromuscular abnormalities or other systemic abnormalities, suggestive of suspected mitochondrial diseases or the necessity for a differential diagnosis of other diseases, underwent rapid mtDNA sequencing concurrently. A diagnosis was made in 18 patients (45.0%, 18/40); three cases with de novo autosomal dominant variants, ten cases with homozygous or compound heterozygous variants, three cases with hemizygous variants inherited from mother, three cases with heterozygous variants inherited from either parent, and one case with a mtDNA mutation. The 18 patients were diagnosed with metabolic (n = 7), immunodeficiency (n = 4), cardiovascular (n = 2), neuromuscular (n = 2) disorders, and others. Genetic testing reports were generated with a median time of 5 days (range, 3–9 days). Thirteen patients that were diagnosed had an available medical treatment and resulted in a positive outcome. We propose that rapid exome sequencing combined with mitochondrial DNA sequencing should be available to patients with suspected mitochondrial diseases or undefined clinical features necessary for making a differential diagnosis of other diseases.


Author(s):  
Gülden Diniz

Evaluation of muscle and nerve biopsy samples is an important diagnostic tool in patients with neuromuscular disease. It can be thought that the great developments in the field of medicine in recent years have reduced the importance of these investigations. However, histopathological examination narrows the genetic diseases panel to be applied in differential diagnosis by reducing possible diagnostic options, especially in the first approach. It also provides information about the severity of the disease that cannot be distinguished by genetic examination in the most frequently seen X-linked dystrophinopathies. It distinguishes inflammatory, metabolic, and mitochondrial diseases that can be confused with hereditary myopathies clinically. In some cases, the differential diagnosis approach is only made with repeated biopsy samples. As a result of the change in the concept of inflammatory neuropathy in nerve biopsies, evaluation of nerve biopsy is very important in the diagnosis of inflammatory neuropathy and in addition to grading myelin loss or axonal degeneration. In this review, it is aimed to emphasize with case examples the conditions where muscle and nerve biopsies are very important.


2021 ◽  
Vol 14 (1) ◽  
pp. e237592
Author(s):  
Elizabeth H Dineen ◽  
Ali Torkamani ◽  
Evan D Muse

Mitochondrial diseases are rare, often go undiagnosed and can lead to devastating cascades of multisystem organ dysfunction. This report of a young woman with hearing loss and gestational diabetes illustrates a novel presentation of a cardiomyopathy caused by a previously described mutation in a mitochondrial gene, MT-TL1. She initially had biventricular heart dysfunction and ventricular arrhythmia that ultimately recovered with beta blockade and time. She continues to participate in sport without decline. It is important to keep mitochondrial diseases in the differential diagnosis and understand the testing and management strategies in order to provide the best patient care.


Author(s):  
Bruce Mackay

The broadest application of transmission electron microscopy (EM) in diagnostic medicine is the identification of tumors that cannot be classified by routine light microscopy. EM is useful in the evaluation of approximately 10% of human neoplasms, but the extent of its contribution varies considerably. It may provide a specific diagnosis that can not be reached by other means, but in contrast, the information obtained from ultrastructural study of some 10% of tumors does not significantly add to that available from light microscopy. Most cases fall somewhere between these two extremes: EM may correct a light microscopic diagnosis, or serve to narrow a differential diagnosis by excluding some of the possibilities considered by light microscopy. It is particularly important to correlate the EM findings with data from light microscopy, clinical examination, and other diagnostic procedures.


2011 ◽  
Vol 21 (2) ◽  
pp. 59-62
Author(s):  
Joseph Donaher ◽  
Christina Deery ◽  
Sarah Vogel

Healthcare professionals require a thorough understanding of stuttering since they frequently play an important role in the identification and differential diagnosis of stuttering for preschool children. This paper introduces The Preschool Stuttering Screen for Healthcare Professionals (PSSHP) which highlights risk factors identified in the literature as being associated with persistent stuttering. By integrating the results of the checklist with a child’s developmental profile, healthcare professionals can make better-informed, evidence-based decisions for their patients.


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