Association of Variants in the SPTLC1 Gene With Juvenile Amyotrophic Lateral Sclerosis.

Importance: Juvenile amyotrophic lateral sclerosis (ALS) is a rare form of ALS characterized by age of symptom onset less than 25 years and a variable presentation. Objective: To identify the genetic variants associated with juvenile ALS. Design, Setting, and Participants: In this multicenter family-based genetic study, trio whole-exome sequencing was performed to identify the disease-associated gene in a case series of unrelated patients diagnosed with juvenile ALS and severe growth retardation. The patients and their family members were enrolled at academic hospitals and a government research facility between March 1, 2016, and March 13, 2020, and were observed until October 1, 2020. Whole-exome sequencing was also performed in a series of patients with juvenile ALS. A total of 66 patients with juvenile ALS and 6258 adult patients with ALS participated in the study. Patients were selected for the study based on their diagnosis, and all eligible participants were enrolled in the study. None of the participants had a family history of neurological disorders, suggesting de novo variants as the underlying genetic mechanism. Main Outcomes and Measures: De novo variants present only in the index case and not in unaffected family members. Results: Trio whole-exome sequencing was performed in 3 patients diagnosed with juvenile ALS and their parents. An additional 63 patients with juvenile ALS and 6258 adult patients with ALS were subsequently screened for variants in the SPTLC1 gene. De novo variants in SPTLC1 (p.Ala20Ser in 2 patients and p.Ser331Tyr in 1 patient) were identified in 3 unrelated patients diagnosed with juvenile ALS and failure to thrive. A fourth variant (p.Leu39del) was identified in a patient with juvenile ALS where parental DNA was unavailable. Variants in this gene have been previously shown to be associated with autosomal-dominant hereditary sensory autonomic neuropathy, type 1A, by disrupting an essential enzyme complex in the sphingolipid synthesis pathway. Conclusions and Relevance: These data broaden the phenotype associated with SPTLC1 and suggest that patients presenting with juvenile ALS should be screened for variants in this gene.

Neurology Care, Diagnostics, and Emerging Therapies of the Patient With Duchenne Muscular Dystrophy.

Duchenne muscular dystrophy is the most common form of childhood muscular dystrophy. A mutation in the DMD gene disrupts dystrophin (protein) production, causing damage to muscle integrity, weakness, loss of ambulation, and cardiopulmonary compromise by the second decade of life. Life expectancy has improved from mid-teenage years to mid-20s with the use of glucocorticoids and beyond the third decade with ventilator support and multidisciplinary care. However, Duchenne muscular dystrophy is associated with comorbidities and is a fatal disease. Glucocorticoids prolong ambulation, but their side effects are significant. Emerging investigational therapies have surfaced over the past decade and have rapidly been tested in clinical trials. Gene-specific strategies include nonsense readthrough, exon skipping, gene editing, utrophin modulation, and gene replacement. Other mechanisms include muscle regeneration, antioxidants, and antifibrosis and anti-inflammatory pathways. With potential therapies emerging, early diagnosis is needed to initiate treatment early enough to minimize morbidity and mortality. Newborn screening can be used to significantly improve early diagnosis, especially for gene-specific therapeutics.

Developing multidisciplinary clinics for neuromuscular care and research.

Multidisciplinary care is considered the standard of care for both adult and pediatric neuromuscular disorders and has been associated with improved quality of life, resource utilization, and health outcomes. Multidisciplinary care is delivered in multidisciplinary clinics that coordinate care across multiple specialties by reducing travel burden and streamlining care. In addition, the multidisciplinary care setting facilitates the integration of clinical research, patient advocacy, and care innovation (e.g., telehealth). Yet, multidisciplinary care requires substantial commitment of staff time and resources. We calculated personnel costs in our ALS clinic in 2015 and found an average cost per patient visit of $580, of which only 45% was covered by insurance reimbursement. In this review, we will describe classic and emerging concepts in multidisciplinary care models for adult and pediatric neuromuscular disease. We will then explore the financial impact of multidisciplinary care with emphasis on sustainability and metrics to demonstrate quality and value. Muscle Nerve 56: 848-858, 2017.

Understanding relationships between autism, intelligence, and epilepsy: a cross-disorder approach.

AIM: As relationships between autistic traits, epilepsy, and cognitive functioning remain poorly understood, these associations were explored in the biologically related disorders tuberous sclerosis complex (TSC), neurofibromatosis type 1 (NF1), and epilepsy. METHOD: The Social Responsiveness Scale (SRS), a quantitative measure of autistic traits, was distributed to caregivers or companions of patients with TSC, NF1, and childhood-onset epilepsy of unknown cause (EUC), and these results were compared with SRS data from individuals with idiopathic autism spectrum disorders (ASDs) and their unaffected siblings. Scores and trait profiles of autistic features were compared with cognitive outcomes, epilepsy variables, and genotype. RESULTS: A total of 180 SRS questionnaires were completed in the TSC, NF1, and EUC outpatient clinics at the Massachusetts General Hospital (90 females, 90 males; mean age 21 y, range 4-63 y), and SRS data from 210 patients with ASD recruited from an autism research collaboration (167 males, 43 females; mean age 9 y, range 4-22 y) and 130 unaffected siblings were available. Regression models showed a significant association between SRS scores and intelligence outcomes (p<0.001) and various seizure variables (p<0.02), but not with a specific underlying disorder or genotype. The level of autistic features was strongly associated with intelligence outcomes in patients with TSC and epilepsy (p<0.01); in patients with NF1 these relationships were weaker (p=0.25). For all study groups, autistic trait subdomains covaried with neurocognitive comorbidity, with endophenotypes similar to that of idiopathic autism. INTERPRETATION: Our data show that in TSC and childhood-onset epilepsy, the severity and phenotype of autistic features are inextricably linked with intelligence and epilepsy outcomes. Such relationships were weaker for individuals with NF1. Findings suggest that ASDs are not specific in these conditions.

Emotional functioning of patients with neurofibromatosis tumor suppressor syndrome.

PURPOSE: Although patients with neurofibromatosis are predisposed to multiple nerve sheath tumors that can develop anywhere in the body and cause significant morbidity (e.g., hearing loss; pain), little research has examined emotional correlates of neurofibromatosis. The purpose of this study was to examine emotional functioning among adult patients with neurofibromatosis. METHODS: A total of 248 patients with neurofibromatosis (neurofibromatosis 1, neurofibromatosis 2, or schwannomatosis) who received care at a specialized clinic completed validated measures to assess symptoms of depression and anxiety, level of perceived stress, and self-esteem. RESULTS: Patients with neurofibromatosis reported significantly more symptoms of depression and anxiety, higher levels of perceived stress, and lower levels of self-esteem as compared with general population norms. No significant differences were found among patients with neurofibromatosis 1, neurofibromatosis 2, and schwannomatosis, and emotional functioning was not significantly associated with disease severity. However, increased symptoms of depression and anxiety, higher levels of perceived stress, and lower levels of self-esteem were associated with a higher frequency of self-reported medical visits in the past year (P values ≤0.05). CONCLUSION: Neurofibromatosis appears to be associated with reduced emotional functioning. Although further research is needed, these findings suggest a role for a multidisciplinary treatment approach to address emotional distress among adult patients with neurofibromatosis.

Optical coherence tomography in the evaluation of neurofibromatosis type-1 subjects with optic pathway gliomas.

PURPOSE: Neurofibromatosis type 1 (NF1) is the most common neurocutaneous disorder, with an approximate incidence of 1 in 3,500. Optic pathway gliomas (OPGs) develop in 15% of individuals with NF1, commonly in childhood. OPGs are difficult to detect via a clinical inspection in children, often requiring magnetic resonance imaging (MRI). Given the significant visual risks associated with OPGs in NF1, there is a need for improved noninvasive techniques to diagnose OPGs in children; therefore, we studied optical coherence tomography (OCT) as a potential tool to assess optic nerve and retinal nerve fiber layer (RNFL) abnormalities. This prospective study was designed to evaluate OCT detection of RNFL loss from optic atrophy attributable to OPGs in a cohort of pediatric patients with NF1. METHODS: With the use of Stratus OCT, directed testing with the Fast Macular Thickness and Fast RNFL Thickness protocol scans were performed on 9 subjects with NF1 and known OPGs, 6 subjects with NF1 without OPGs, and 15 controls. RESULTS: NF1 subjects with OPGs had thinner RNFLs and macula when compared with age-matched controls and to NF1 subjects without OPGs. After applying the equivalence equation, the average RNFL thickness and macular volume in NF1 subjects without OPGs was equivalent to controls. CONCLUSIONS: Our study suggests that OCT can be used to detect RNFL thinning secondary to OPGs in NF1 subjects. This objective tool shows promise as a useful adjunct to routine clinical ophthalmologic evaluation in children with NF1.

Spontaneous resolution of a 13-mm Chiari malformation Type I in relation to differential growth of the posterior fossa volume.

The case of a 3-year-old patient with tuberous sclerosis and a 13-mm Chiari malformation Type I that spontaneously disappeared over the course of 4 years is presented. Using morphometric measurements of the posterior fossa and cerebellum in this patient, the authors show that the volume of the posterior fossa at the time of initial evaluation was consistent with that reported as normal in the literature (180.24 cm3; normal volume 132-198 cm3). Moreover, the patient showed a normal rate of growth of his posterior fossa over the period of observation (201.05 cm3; normal range 153-230 cm3). Cerebellar volumes were found to increase only minimally during this time period, which is compatible with observations in healthy controls. The posterior fossa volume, on the other hand, was shown to increase significantly more than that of the cerebellum (p=0.0185). This differential growth may permit the tonsils to ascend back up into the posterior fossa. Therefore, pediatric patients with normal posterior fossa volumes and normal development may have a spontaneous resolution of their asymptomatic Chiari malformation Type I.