Progressive proximal spinal and bulbar muscular atrophy of late onset: a sex-linked recessive trait.

93rd ENMC international workshop: non-5q-spinal muscular atrophies (SMA) – clinical picture (6–8 April 2001, Naarden, The Netherlands)

Diseases are sometimes known by many names 1–9, which complicates the retrieval of publications. Rare and emerging diseases may be especially vulnerable to this. Health sciences librarians do not often encounter rare diseases and may be unaware of the search challenges that these diseases present. To effectively retrieve publications for research, a strategy to identify all the different names of a disease is needed so that these can be incorporated into a comprehensive search. The author was engaged in a research project to create a comprehensive bibliography of the rare disease spinal and bulbar muscular atrophy (SBMA). The project utilized a strategy to identify all of the various names for the disease. This strategy should be helpful not only for SBMA researchers, but for anyone interested in a methodology for obtaining a comprehensive list of names for a disease. Spinal and bulbar muscular atrophy (SBMA) SBMA (ORPHA481, OMIM #313200, SNOMED CT Concept ID 230253001†) is a rare progressive neuromuscular disorder of males marked by proximal muscle weakness, cramping, fasciculations (twitching of individual muscle fibers), and muscle atrophy. Symptoms have been reported to first begin to develop between the third to sixth decades of life. Prevalence of SBMA has been reported alternately as 1 in 40,000 10, 1–2 in 100,000 11, and less than 1 in 50,000 live male births 12, but it is thought to be underdiagnosed 13–15. Degeneration of anterior horn cells (lower motor neurons) in the spinal cord of affected individuals is observed. Additional symptoms may include gynecomastia (abnormal growth of breasts in males), testicular atrophy, dysarthria (difficulty speaking), and dysphagia (difficulty swallowing). At this time, there is no known cure for most such neuromuscular diseases 16. Inheritance of SBMA is by traditional X-linked genetics. The disorder is related to a genetic defect in which a trinucleotide repeat occurs in the first exon of the androgen receptor gene on the X chromosome, first identified by La Spada in 1991 17. The string of three nucleotides of a trinucleotide repeat is present in a normal gene but is an unusually long string in a defective gene. The trinucleotide repeat of SBMA is cytosine-adenine-guanine (CAG), which codes for the amino acid glutamine. The presence of the repeat in DNA translation results in a string of glutamine molecules in the resulting peptide. Normal CAG repeat length in the androgen receptor gene is 11–34. SBMA is diagnosed if the number of CAG repeats exceeds 38 18, 19. Women do not develop SBMA, but heterozygous and homozygous women may exhibit mild symptoms, particularly muscle twitching and cramping 13, 20, 21. SBMA was identified as a unique disorder in 1968 by William R. Kennedy, but the disorder existed before its discovery 22. As far back as 1897, Japanese neurologist Hiroshi Kawahara first described what appeared to be SBMA in two brothers suffering from muscle atrophy and fasciculation of the tongue and limbs, with adult onset and sex-linked recessive inheritance 23, 24. Several disorders of varying severity and outcomes resemble SBMA, and the disorder is thought to be frequently misdiagnosed 25–29. The most well known is amyotrophic lateral sclerosis. The most challenging are the spinal muscular atrophies (SMA). However, SMA is an autosomal recessive genetic disease. Symptoms of most forms of SMA arise in childhood, but SMA3 is suggested to possibly first appear in adolescence or young adulthood. SMA4 symptoms may appear after age 30 30.

Motor neuron disorders (MNDs) are a heterogeneous group of diseases that result from degeneration of motor neurons. If both upper and lower motor neurons (UMNs and LMNs) are affected, the...

Motor neuron diseases (MNDs) are neurodegenerative disorders characterized by upper and/or lower MN loss. MNDs include amyotrophic lateral sclerosis (ALS), spinal muscular atrophy (SMA), and spinal and bulbar muscular atrophy (SBMA). Despite variability in onset, progression, and genetics, they share a common skeletal muscle involvement, suggesting that it could be a primary site for MND pathogenesis. Due to the key role of muscle-specific microRNAs (myomiRs) in skeletal muscle development, by real-time PCR we investigated the expression of miR-206, miR-133a, miR-133b, and miR-1, and their target genes, in G93A-SOD1 ALS, Δ7SMA, and KI-SBMA mouse muscle during disease progression. Further, we analyzed their expression in serum of SOD1-mutated ALS, SMA, and SBMA patients, to demonstrate myomiR role as noninvasive biomarkers. Our data showed a dysregulation of myomiRs and their targets, in ALS, SMA, and SBMA mice, revealing a common pathogenic feature associated with muscle impairment. A similar myomiR signature was observed in patients’ sera. In particular, an up-regulation of miR-206 was identified in both mouse muscle and serum of human patients. Our overall findings highlight the role of myomiRs as promising biomarkers in ALS, SMA, and SBMA. Further investigations are needed to explore the potential of myomiRs as therapeutic targets for MND treatment.

Patient and parent oriented tools to assess health-related quality of life, activity of daily living and caregiver burden in SMA. Rome, 13 July 2019

Motor neuron diseases encompass a range of phenotypes, including amyotrophic lateral sclerosis (ALS), primary lateral sclerosis (PLS), progressive muscular atrophy (PMA), and spinal muscular atrophy (SMA). Related conditions include spinal and bulbar muscular atrophy (SBMA) and hereditary motor and sensory neuropathy with proximal dominant involvement (HMSN-P). Hereditary spastic paraplegia (HSP)-a group of disorders primarily affecting the corticospinal tract-also exhibits diverse clinical manifestations. This review summarizes the genetic basis of these diseases, along with their clinical characteristics, diagnostic approaches, and disease-specific therapies.

BackgroundRare neurological diseases (RNDs) result in severe health burdens worldwide. Data from China are limited. We aimed to investigate the health burden of 20 RNDs in Guangdong Province (GD), which contains two-thirds of the population of South China.MethodsThe hospitalization data of 20 RNDs were described using hospital-based front sheet data from 3,037 hospitals of GD from 2016 to 2022. The 20 RNDs included amyotrophic lateral sclerosis (ALS), Charcot-Marie-Tooth Disease, cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy, congenital myotonia, congenital myasthenic syndrome, Dravet syndrome, Fabry disease, hereditary spastic paraplegia, Huntington disease, Leber hereditary optic neuropathy, mitochondrial encephalopathy (ME), multi-focal motor neuropathy, myotonic dystrophy, primary hereditary dystonia, progressive muscular dystrophy (PMD), spinal and bulbar muscular atrophy, spinal muscular atrophy (SMA), spinocerebellar ataxia, Wilson disease (WD) and X-linked adrenoleukodystrophy. Age were presented as mean and standard deviation while length of hospital stay as median and interquartile range (25th and 75th percentiles). The other variables were described as number and percentage. The data were analyzed by Joinpoint regression.ResultsThere were 9,351 cases, including 330 ICU and 155 death cases. The average age was 33.7 ± 22.0 y, and 63.8% of patients were male. From 2016 to 2022, the number of RND (and juvenile RND) cases were 1034 (184), 1174 (293), 1443 (374), 1422 (320), 1331 (337), 1432 (409) to 1515 (515). ICU (and juvenile ICU) cases rose from 28 (3), 34 (6), 24 (4), 38 (11), 46 (13), 54 (24) to 106 (56). Joinpoint regression showed significant upward trend in percentages of juvenile and juvenile ICU cases (APC = 8.13, P< 0.05; APC = 28.42, P< 0.05). The fop five RNDs were WD, ASL, PMD, ME, and SMA, which accounted for 79.7% of all, 99.1% of ICU, and 94.8% of death cases.ConclusionsWe demonstrated that the increase in health burden of RNDs was mainly evident in juveniles in South China from 2016 to 2022. The top 5 RNDs accounted for majority of the critical patients.

Infantile autosomal recessive spinal muscular atrophy (type I) represents a lethal disorder leading to progressive symmetric muscular atrophy of limb and trunk muscles. Ninety-six percent cases of spinal muscular atrophy type I are caused by deletions or mutations in the survival motoneuron gene (SMNI) on chromosome 5q11.2-13.3. However, a number of chromosome 5q-negative patients with additional clinical features (respiratory distress, cerebellar hypoplasia) have been designated in the literature as infantile spinal muscular atrophy plus forms. In addition, the combination of severe spinal muscular atrophy and neurogenic arthrogryposis has been described. We present clinical, molecular, and autopsy findings of a newborn boy presenting with generalized muscular atrophy in combination with congenital bone fractures and extremely thin ribs but without contractures.

Motor neuron disease (MND) is a group of neurological disorders which is characterized by selectively progressive degeneration of motor neurons in the brain and spinal cord. On the basis of the degree of upper or lower neuron involvement, MND is broadly divided into several subtypes: pure upper neuron diseases (primary lateral sclerosis), pure lower motor neuron diseases (progressive spinal muscular atrophy, progressive bulbar palsy, spinal muscular atrophy, X-linked spinal and bulbar muscular atrophy, etc.), and mixed upper and lower motor neuron diseases (amyotrophic lateral sclerosis). Generally, MND can be sporadic, or it can occur as an inherited disorder. To date, a great number of genes have been identified to be responsible for inherited MND. The distinct causative genes usually result in different clinical phenotypes. Therefore, the genetic testing is crucial for inherited MND. In this chapter, we mentioned several cases of inherited motor neuron diseases and described the way how these definitive causative genes were identified. In addition, to make clear definition for MND, several other inherited neurologic diseases, such as hereditary spasticity paraplegia and inherited peripheral neuropathy, were also presented in this chapter.

FP.10 Combination of BIO101 with antisense oligonucleotide therapy demonstrates synergistic beneficial effects in severe SMA-like mice

Nasometric Scores in spinal and bulbar muscular atrophy - Effects of palatal lift prosthesis on dysarthria and dysphagia

Proximal spinal muscular atrophy (SMA), a leading genetic cause of infant death worldwide, is an early-onset, autosomal recessive neurodegenerative disease characterized by the loss of spinal α-motor neurons. This loss of α-motor neurons is associated with muscle weakness and atrophy. SMA can be classified into five clinical grades based on age of onset and severity of the disease. Regardless of clinical grade, proximal SMA results from the loss or mutation of SMN1 (survival motor neuron 1) on chromosome 5q13. In humans a large tandem chromosomal duplication has lead to a second copy of the SMN gene locus known as SMN2. SMN2 is distinguishable from SMN1 by a single nucleotide difference that disrupts an exonic splice enhancer in exon 7. As a result, most of SMN2 mRNAs lack exon 7 (SMNΔ7) and produce a protein that is both unstable and less than fully functional. Although only 10–20% of the SMN2 gene product is fully functional, increased genomic copies of SMN2 inversely correlates with disease severity among individuals with SMA. Because SMN2 copy number influences disease severity in SMA, there is prognostic value in accurate measurement of SMN2 copy number from patients being evaluated for SMA. This prognostic value is especially important given that SMN2 copy number is now being used as an inclusion criterion for SMA clinical trials. In addition to SMA, copy number variations (CNVs) in the SMN genes can affect the clinical severity of other neurological disorders including amyotrophic lateral sclerosis (ALS) and progressive muscular atrophy (PMA). This review will discuss how SMN1 and SMN2 CNVs are detected and why accurate measurement of SMN1 and SMN2 copy numbers is relevant for SMA and other neurodegenerative diseases.

Frontotemporal involvement has been extensively investigated in amyotrophic lateral sclerosis (ALS) but remains relatively poorly characterized in other motor neuron disease (MND) phenotypes such as primary lateral sclerosis (PLS), progressive muscular atrophy (PMA), spinal muscular atrophy (SMA), spinal bulbar muscular atrophy (SBMA), post poliomyelitis syndrome (PPS), and hereditary spastic paraplegia (HSP). This review focuses on insights from structural, metabolic, and functional neuroimaging studies that have advanced our understanding of extra-motor disease burden in these phenotypes. The imaging literature is limited in the majority of these conditions and frontotemporal involvement has been primarily evaluated by neuropsychology and post mortem studies. Existing imaging studies reveal that frontotemporal degeneration can be readily detected in ALS and PLS, varying degree of frontotemporal pathology may be captured in PMA, SBMA, and HSP, SMA exhibits cerebral involvement without regional predilection, and there is limited evidence for cerebral changes in PPS. Our review confirms the heterogeneity extra-motor pathology across the spectrum of MNDs and highlights the role of neuroimaging in characterizing anatomical patterns of disease burden in vivo. Despite the contribution of neuroimaging to MND research, sample size limitations, inclusion bias, attrition rates in longitudinal studies, and methodological constraints need to be carefully considered. Frontotemporal involvement is a quintessential clinical facet of MND which has important implications for screening practices, individualized management strategies, participation in clinical trials, caregiver burden, and resource allocation. The academic relevance of imaging frontotemporal pathology in MND spans from the identification of genetic variants, through the ascertainment of presymptomatic changes to the design of future epidemiology studies.

Spinal Muscular Atrophy in the Neonate

Endoplasmic reticulum stress and unfolded protein response: Roles in skeletal muscle atrophy.