Systematic Review of Presymptomatic Treatment for Spinal Muscular Atrophy.

Spinal muscular atrophy (SMA) causes the degeneration of motor neurons in the spinal cord. Treatments including nusinersen, risdiplam, and onasemnogene abeparvovec have been shown to be effective in reducing symptoms, with recent studies suggesting greater effectiveness when treatment is initiated in the presymptomatic stage. This systematic review synthesises findings from prospective studies of presymptomatic treatment for 5q SMA published up to December 2023. The review identified three single-arm interventional studies of presymptomatic treatment (NURTURE, RAINBOWFISH, and SPR1NT), six observational studies comparing presymptomatic or screened cohorts versus symptomatic cohorts, and twelve follow-up studies of screened cohorts only (i.e., babies identified via newborn screening for SMA). Babies with three SMN2 copies met most motor milestones in the NURTURE study of nusinersen and in the SPR1NT study of onasemnogene abeparvovec. Babies with two SMN2 copies in these two studies met most motor milestones but with some delays, and some required ventilatory or feeding support. The RAINBOWFISH study of risdiplam is ongoing. Naïve comparisons of presymptomatic treatment in SPR1NT, versus untreated or symptomatic treatment cohorts, suggested improved outcomes in patients treated presymptomatically. Comparative observational studies supported the finding that presymptomatic treatment, and early treatment following screening, may improve outcomes compared with treatment at the symptomatic stage. Further research should assess the long-term clinical outcomes and cost-effectiveness of presymptomatic treatment for SMA.

Systematic Review of Newborn Screening Programmes for Spinal Muscular Atrophy.

Spinal muscular atrophy (SMA) is a genetic neuromuscular disorder causing the degeneration of motor neurons in the spinal cord. Recent studies suggest greater effectiveness of treatment in the presymptomatic stage. This systematic review synthesises findings from 37 studies (and 3 overviews) of newborn screening for SMA published up to November 2023 across 17 countries to understand the methodologies used; test accuracy performance; and timing, logistics and feasibility of screening. All studies screened for the homozygous deletion of SMN1 exon 7. Most (28 studies) used RT-PCR as the initial test on dried blood spots (DBSs), while nine studies also reported second-tier tests on DBSs for screen-positive cases. Babies testing positive on DBSs were referred for confirmatory testing via a range of methods. Observed SMA birth prevalence ranged from 1 in 4000 to 1 in 20,000. Most studies reported no false-negative or false-positive cases (therefore had a sensitivity and specificity of 100%). Five studies reported either one or two false-negative cases each (total of six cases; three compound heterozygotes and three due to system errors), although some false-negatives may have been missed due to lack of follow-up of negative results. Eleven studies reported false-positive cases, some being heterozygous carriers or potentially related to heparin use. Time to testing and treatment varied between studies. In conclusion, several countries have implemented newborn screening for SMA in the last 5 years using a variety of methods. Implementation considerations include processes for timely initial and confirmatory testing, partnerships between screening and neuromuscular centres, and timely treatment initiation.

How many phenotypes for the FBXO11 related disease? Report on a new patient with a tricho-rhino-phalangeal like phenotype.

Here we report the case of a young boy with developmental delay, thin sparse hair, early closure of the anterior fontanel, bilateral choanal atresia, brachyturicephaly; and dysmorphic features closely resembling those seen in trichorhinophalangeal syndrome (TRPS). These features include sparse hair, sparse lateral eyebrows, a bulbous pear shaped nose, a long philtrum, thin lips, small/hypoplastic nails, pes planovalgus; bilateral cone-shaped epiphyses at the proximal 5th phalanx, slender long bones, coxa valga, mild scoliosis, and delayed bone age. Given that TRPS had been excluded by a thorough genetic analysis, whole exome sequencing was performed and a heterozygous likely pathogenic variant was identified in the FBXO11 gene (NM_001190274.2: c.1781A > G; p. His594Arg), confirming the diagnosis of the newly individualized IDDFBA syndrome: Intellectual Developmental Disorder, dysmorphic Facies, and Behavioral Abnormalities (OMIM# 618,089). Our findings further delineate the clinical spectrum linked to FBXO11 and highlight the importance of investigating further cases with mutations in this gene to establish a potential genotype-phenotype correlation.

Survey of service needs to embed genome sequencing for motor neuron disease in neurology in the English National Health Service.

All people with motor neuron disease (pwMND) in England are eligible for genome sequencing (GS), with panel-based testing. With the advent of genetically targeted MND treatments, and increasing demand for GS, it is important that clinicians have the knowledge and skills to support pwMND in making informed decisions around GS. We undertook an online survey of clinical genomic knowledge and genetic counselling skills in English clinicians who see pwMND. There were 245 respondents to the survey (160 neurology clinicians and 85 genetic clinicians). Neurology clinicians reported multiple, overlapping barriers to offering pwMND GS. Lack of time to discuss GS in clinic and lack of training in genetics were reported. Neurology clinicians scored significantly less well on self-rated genomic knowledge and genetic counselling skills than genetic clinicians. The majority of neurology clinicians reported that they do not have adequate educational or patient information resources to support GS discussions. We identify low levels of genomic knowledge and skills in the neurology workforce. This may impede access to GS and precision medicine for pwMND.

Variability of Multiple Sclerosis Walking Scale and Multiple Sclerosis Impact Scale Scores in People Without Multiple Sclerosis.

Introduction  Many people with multiple sclerosis (pwMS) experience problems with mobility at some point in their disease course. The Multiple Sclerosis Impact Scale (MSIS) and Multiple Sclerosis Walking Scale (MSWS) are validated patient-reported outcome measures of physical impairment in pwMS. The range of scores on MSIS and MSWS in people without MS (pwoMS) are not well understood. Methods People over the age of 16 who did not have a diagnosis of multiple sclerosis (MS) were invited to complete an online survey consisting of a general health questionnaire, MSIS and the MSWS. Scores for MSIS and MSWS from pwoMS were compared to those from a cohort of 35 pwMS from a previous study. Scores for MSIS and MSWS were correlated with age, sex and comorbidities in pwoMS. Results One hundred eighty-nine ambulant pwoMS were recruited (52.5% female), aged over 16 years of age. Ninety-nine percent reported no difficulty with walking, 89.4% were non-smokers, and 14% had a physical co-morbidity. None used a walking aid. For pwoMS, the MSIS score was a mean of 39.14±13.75 (range 29-127), compared to a mean of 77.2±24.94 (range 40-126) for pwMS. For pwoMS, the mean MSWS score was 8.46±16.2 (0-87) compared to a mean of 56.9±28.9 (4-100) for pwMS. There was no significant effect of sex or smoking on MSIS or MSWS scores in pwoMS. Presence of a physical co-morbidity was associated with significantly higher MSIS and MSWS scores in pwoMS. There was a significant correlation of increasing age with increasing MSWS score in pwoMS but no correlation of age with MSIS score. Conclusion There is a wide range of MSWS and MSIS scores in pwoMS. The age and presence of comorbidities influence both MSWS and MSIS scores. Our findings have implications for the selection of control groups for clinical studies in pwMS.

A report of resources used by clinicians in the UK to support motor neuron disease genomic testing.

Genetic testing is a key decision-making point for people with motor neuron disease (MND); to establish eligibility for clinical trials, better understand the cause of their condition, and confirm the potential risk to relatives, who may be able to access predictive testing. Given the wide-reaching implications of MND genetic and predictive testing, it is essential that families are given adequate information, and that staff are provided with appropriate training. In this report we overview the information resources available to people with MND and family members around genetic testing, and the educational and training resources available to staff, based on information obtained through a freedom of information request to UK-based NHS Trusts. MND Association resources were most commonly used in information sharing, though we highlight distinctions between neurology and genetics centers. No respondents identified comprehensive training around MND genetic testing. We conclude with practice implications and priorities for the development of resources and training.

Multimodal assessment of mitochondrial function in Parkinson's disease.

The heterogenous aetiology of Parkinson's disease is increasingly recognized; both mitochondrial and lysosomal dysfunction have been implicated. Powerful, clinically applicable tools are required to enable mechanistic stratification for future precision medicine approaches. The aim of this study was to characterize bioenergetic dysfunction in Parkinson's disease by applying a multimodal approach, combining standardized clinical assessment with midbrain and putaminal 31-phosphorus magnetic resonance spectroscopy (31P-MRS) and deep phenotyping of mitochondrial and lysosomal function in peripheral tissue in patients with recent-onset Parkinson's disease and control subjects. Sixty participants (35 patients with Parkinson's disease and 25 healthy controls) underwent 31P-MRS for quantification of energy-rich metabolites [ATP, inorganic phosphate (Pi) and phosphocreatine] in putamen and midbrain. In parallel, skin biopsies were obtained from all research participants to establish fibroblast cell lines for subsequent quantification of total intracellular ATP and mitochondrial membrane potential (MMP) as well as mitochondrial and lysosomal morphology, using high content live cell imaging. Lower MMP correlated with higher intracellular ATP (r = -0.55, P = 0.0016), higher mitochondrial counts (r = -0.72, P < 0.0001) and higher lysosomal counts (r = -0.62, P = 0.0002) in Parkinson's disease patient-derived fibroblasts only, consistent with impaired mitophagy and mitochondrial uncoupling. 31P-MRS-derived posterior putaminal Pi/ATP ratio variance was considerably greater in Parkinson's disease than in healthy controls (F-tests, P = 0.0036). Furthermore, elevated 31P-MRS-derived putaminal, but not midbrain Pi/ATP ratios (indicative of impaired oxidative phosphorylation) correlated with both greater mitochondrial (r = 0.37, P = 0.0319) and lysosomal counts (r = 0.48, P = 0.0044) as well as lower MMP in both short (r = -0.52, P = 0.0016) and long (r = -0.47, P = 0.0052) mitochondria in Parkinson's disease. Higher 31P-MRS midbrain phosphocreatine correlated with greater risk of rapid disease progression (r = 0.47, P = 0.0384). Our data suggest that impaired oxidative phosphorylation in the striatal dopaminergic nerve terminals exceeds mitochondrial dysfunction in the midbrain of patients with early Parkinson's disease. Our data further support the hypothesis of a prominent link between impaired mitophagy and impaired striatal energy homeostasis as a key event in early Parkinson's disease.

Short report: Behavioural characterisation of SOX11 syndrome.

BACKGROUND: SOX11 syndrome is a rare condition caused by deletions or de novo point mutations of the SOX11 gene. SOX11 is a transcription factor gene that plays an important role in brain development. AIMS: The aim of this study was to quantitatively evaluate the behavioural profiles of individuals with SOX11 syndrome. METHODS AND PROCEDURES: The Vineland Adaptive Behaviour Scales 3 (VABS-3) and the Social Responsiveness Scale 2 (SRS-2) were completed by parents of 21 children and young adults with SOX11 syndrome. OUTCOMES AND RESULTS: Most were found to have borderline (33 %) or mild (39 %) impairment in adaptive behaviour, with more difficulties in communication and daily living than socialisation in the cohort overall. Most (90 %) were found to exhibit clinically relevant levels of autistic traits, with 62 % scoring in the "severe" range, though social motivation was observed to be a relative strength in the cohort overall. CONCLUSIONS AND IMPLICATIONS: This study presents the first standardised evaluation of adaptive behaviour and autistic traits of individuals with SOX11 syndrome. This will improve clinicians, educators and parents' understanding of SOX11 syndrome.