Correlation Between the SARA and A-T NEST Clinical Severity Scores in Adults with Ataxia-Telangiectasia.

Ataxia-Telangiectasia (A-T) is an autosomal recessive neurodegenerative disease associated with cerebellar ataxia and extrapyramidal features. A-T has a complex and diverse phenotype with varying rates of disease progression. The development of robust natural history studies and therapeutic trials relies on the accurate recording of phenotype using relevant and validated severity of illness indexes. We compared the commonly used Scale for the Assessment and Rating of Ataxia (SARA) and the disease-specific A-T Neurological Examination Scale Toolkit (A-T NEST), in our adult A-T cohort. We found a strong correlation between A-T NEST and the established SARA score, validating the use of A-T NEST and SARA in capturing the natural history of A-T patients.

Heterozygous UCHL1 loss-of-function variants cause a neurodegenerative disorder with spasticity, ataxia, neuropathy, and optic atrophy.

PURPOSE: Biallelic variants in UCHL1 have been associated with a progressive early-onset neurodegenerative disorder, autosomal recessive spastic paraplegia type 79. In this study, we investigated heterozygous UCHL1 variants on the basis of results from cohort-based burden analyses. METHODS: Gene-burden analyses were performed on exome and genome data of independent cohorts of patients with hereditary ataxia and spastic paraplegia from Germany and the United Kingdom in a total of 3169 patients and 33,141 controls. Clinical data of affected individuals and additional independent families were collected and evaluated. Patients' fibroblasts were used to perform mass spectrometry-based proteomics. RESULTS: UCHL1 was prioritized in both independent cohorts as a candidate gene for an autosomal dominant disorder. We identified a total of 34 cases from 18 unrelated families, carrying 13 heterozygous loss-of-function variants (15 families) and an inframe insertion (3 families). Affected individuals mainly presented with spasticity (24/31), ataxia (28/31), neuropathy (11/21), and optic atrophy (9/17). The mass spectrometry-based proteomics showed approximately 50% reduction of UCHL1 expression in patients' fibroblasts. CONCLUSION: Our bioinformatic analysis, in-depth clinical and genetic workup, and functional studies established haploinsufficiency of UCHL1 as a novel disease mechanism in spastic ataxia.

White Matter Hyperintensities and Cerebral Microbleeds in Ataxia-Telangiectasia.

BACKGROUND AND OBJECTIVES: To systematically assess the occurrence of cerebral microbleeds (CMBs) and white matter hyperintensities (WMHs) in the largest published cohort of adults with ataxia-telangiectasia (AT). METHODS: We assessed 38 adults with AT (age range 18-55 years) including 15 classic and 23 variant AT, evaluated by two independent assessors. WMHs were quantified on T2-fluid attenuated inversion recovery images using the semiquantitative modified Scheltens and Fazekas scales and CMB on susceptibility-weighted imaging and T2*-weighted gradient echo sequences using the Brain Observer MicroBleed Scale. RESULTS: CMBs were more frequently found in classic AT compared with variant AT (66.7% vs 5.9%) predominantly in cortical and subcortical regions. WMHs were seen in 25 (73.5%) probands and CMBs in 9 (31.0%). The burden of WMHs increased with age, and WMHs were focused in periventricular and deep white matter regions. WMHs were more frequently seen in variant than classic AT. DISCUSSION: This cohort study confirms that WMHs and CMBs are a frequent finding in AT. Further longitudinal studies are required to understand how WMHs and CMBs relate to the neurodegeneration that occurs in AT and the predisposition to cerebral hemorrhage.

Primary mitochondrial myopathies in childhood.

Primary mitochondrial myopathies are genetic metabolic disorders of mitochondrial dysfunction affecting mainly, but not exclusively, skeletal muscle. Although individually rare, they are the most common inherited metabolic disorders in childhood. They can be similar to other childhood muscle diseases such as congenital myopathies, dystrophies, myasthenic syndromes or metabolic myopathies and a muscle biopsy and genetic testing are important in the differential diagnosis. Mitochondrial myopathies can present at any age but typically childhood onset myopathies have more significant muscle involvement and are caused by genes encoded in the nuclear DNA. Mitochondrial myopathy in infants presents with hypotonia, muscle weakness and difficulty feeding. In toddlers and older children delayed motor development, exercise intolerance and premature fatigue are common. A number of nuclear DNA and mitochondrial DNA encoded genes are known to cause isolated myopathy in childhood and they are important in a range of mitochondrial functions such as oxidative phosphorylation, mitochondrial transcription/translation and mitochondrial fusion/fission. A rare cause of isolated myopathy in children, reversible infantile respiratory chain deficiency myopathy, is non-progressive and typically associated with spontaneous full recovery. Promising targeted treatments have been reported for a number or mitochondrial myopathies including riboflavin in ACAD9 and ETFDH-myopathies and deoxynucleoside for TK2-related disease.

Targeted Therapies for Leigh Syndrome: Systematic Review and Steps Towards a 'Treatabolome'.

BACKGROUND: Leigh syndrome (LS) is the most frequent paediatric clinical presentation of mitochondrial disease. The clinical phenotype of LS is highly heterogeneous. Though historically the treatment for LS is largely supportive, new treatments are on the horizon. Due to the rarity of LS, large-scale interventional studies are scarce, limiting dissemination of information of therapeutic options to the wider scientific and clinical community. OBJECTIVE: We conducted a systematic review of pharmacological therapies of LS following the guidelines for FAIR-compliant datasets. METHODS: We searched for interventional studies within Clincialtrials.gov and European Clinical trials databases. Randomised controlled trials, observational studies, case reports and case series formed part of a wider MEDLINE search. RESULTS: Of the 1,193 studies initially identified, 157 met our inclusion criteria, of which 104 were carried over into our final analysis. Treatments for LS included very few interventional trials using EPI-743 and cysteamine bitartrate. Wider literature searches identified case series and reports of treatments repleting glutathione stores, reduction of oxidative stress and restoration of oxidative phosphorylation. CONCLUSIONS: Though interventional randomised controlled trials have begun for LS, the majority of evidence remains in case reports and case series for a number of treatable genes, encoding cofactors or transporter proteins of the mitochondria. Our findings will form part of the international expert-led Solve-RD efforts to assist clinicians initiating treatments in patients with treatable variants of LS.

Ataxia telangiectasia: what the neurologist needs to know.

Ataxia telangiectasia is an autosomal recessive DNA repair disorder characterised by complex neurological symptoms, with an elevated risk of malignancy, immunodeficiency and other systemic complications. Patients with variant ataxia telangiectasia-with some preserved ataxia telangiectasia-mutated (ATM) kinase activity-have a milder and often atypical phenotype, which can lead to long delays in diagnosis. Clinicians need to be aware of the spectrum of clinical presentations of ataxia telangiectasia, especially given the implications for malignancy surveillance and management. Here, we review the phenotypes of ataxia telangiectasia, illustrated with case reports and videos, and discuss its pathological mechanisms, diagnosis and management.

Guillain-Barré syndrome associated with COVID-19 infection: a case from the UK.

Originating from Wuhan, China, COVID-19 has rapidly spread worldwide. Neurological manifestations are more commonly associated with severe COVID-19 infection. Guillain-Barré syndrome (GBS) is a rare immune-mediated postinfectious neuropathy. It has been reported as a possible rare complication of COVID-19. We report a case of GBS associated with COVID-19 in the UK.

Changes in choline metabolism as potential biomarkers of phospholipase C{gamma}1 inhibition in human prostate cancer cells.

Phosphoinositide-specific phospholipase Cγ1 (PLCγ1) is activated downstream of many receptor tyrosine kinases to promote cell motility. Inhibition of this protein is being explored as a therapeutic strategy for blocking cancer cell invasion and metastasis. The clinical development of such cytostatic therapies requires the implementation of pharmacodynamic biomarkers of target modulation. In this study, we use magnetic resonance spectroscopy to explore metabolic biomarkers of PLCγ1 down-regulation in PC3LN3 prostate cancer cells. We show that inhibition of PLCγ1 via an inducible short hairpin RNA system causes a reduction in phosphocholine levels by up to 50% relative to the control as detected by (1)H and (31)P magnetic resonance spectroscopy analyses. This correlated with a rounded-up morphology and reduced cell migration. Interestingly, the fall in phosphocholine levels was not recorded in cells with constitutive PLCγ1 knockdown where the rounded-up phenotype was no longer apparent. This study reveals alterations in metabolism that accompany the cellular effects of PLCγ1 knockdown and highlights phosphocholine as a potential pharmacodynamic biomarker for monitoring the action of inhibitors targeting PLCγ1 signaling.