ABSTRACT
Monomelic Amyotrophy (MMA) is a rare neurological disorder restricted to one upper limb, predominantly affecting young males with an unknown aetiopathogenesis. We report a familial case of father-son duo affected by MMA. Whole exome sequencing identified genetic variations in SLIT1, RYR3 and ARPP21 involved in axon guidance, calcium homeostasis and regulation of calmodulin signaling respectively. This is the first attempt to define genetic modifiers associated with MMA from India and advocates to extend genetic screening to a larger cohort. Deciphering the functional consequences of variations in these genes will be crucial for unravelling the pathogenesis of MMA.
ABSTRACT
BACKGROUND: Amyotrophic lateral sclerosis (ALS) is a relatively rare neurological disorder affecting upper and lower motor neurons in the brain and spinal cord with survival for 3-5 years and rarely beyond 10 years. Sleep disturbances in ALS are underreported and undertreated and there is no related data from India. This study aimed to assess the frequency of sleep disorders in patients of ALS and their determinants. METHODS: Patients with definite and probable ALS as per the El Escorial criteria were recruited from May 2014 to April 2016. Functional impairment, presence of sleep specific abnormalities and anxiety and depression were assessed using standardized questionnaires. RESULTS: Forty patients with ALS (23 male; 17 female) with their median age at presentation being 58.5 years (range 44-75 years) and the median duration of illness being 18 months (range: 4-120 months) were includedin the study. Half of the patients had poor sleep quality, which was significantly worse across all components of Pittsburgh Sleep Quality Index (PSQI) compared to controls. Sleep disorders were observed in 70%, insomnia in 65%, sleep disordered breathing/hypoventilation in 52.5% and restless legs syndrome in 5% patients. Night time awakenings attributable to symptoms associated with ALS were noted in 85%, and anxiety and depression in 57.5% patients. Excessive daytime somnolence emerged as an independent predictor for the presence of sleep disorders in ALS patients on multivariate logistic regression [P = 0.043, odd's ratio (OR) 1.435; 95% confidence interval[CI] (1.011-2.036)]. CONCLUSION: This is the first study from India providing insight into the presence of sleep disorders in ALS. About half of the patients of ALS had a poor sleep quality and two-thirds suffered from sleep disturbances.
Subject(s)
Amyotrophic Lateral Sclerosis/complications , Sleep Wake Disorders/epidemiology , Adult , Aged , Female , Humans , India , Male , Middle Aged , Prevalence , Prospective Studies , Surveys and QuestionnairesABSTRACT
Misfolded protein aggregates are the hallmark of Amyotrophic Lateral Sclerosis (ALS) which suggests involvement of protein homeostasis pathways in etiology of ALS. However, status of protein homeostasis in peripheral blood of ALS is not well established. We analyzed expression levels of key genes of proteostasis pathways in peripheral blood mononuclear cells (PBMCs) of sporadic ALS (sALS) patients and healthy controls. Increased protein carbonylation was observed in patients reflecting oxidative damage in PBMCs. We observed increased transcript and protein levels of GRP78 suggesting Endoplasmic reticulum (ER) insult to cells. Further, significant upregulation of spliced XBP1 and two stress sensors: IRE1α/ERN1 and ATF6 indicated induction of unfolded protein response (UPR). Genes involved in autophagosome initiation (ULK1, ULK2, ATG13); nucleation and elongation (BECLIN1, ATG7, ATG16L1, ATG5, ATG10) and vesicular trafficking genes were significantly increased in patients. Increased lipidation of LC3 validated induction of autophagy. Accumulation of low molecular weight ubiquitinated proteins in patients suggested deregulation of proteasome (UPS) pathway. In addition, cytosolic chaperones (HSP70 and HSP27) and HSF1 were elevated in patients. Increased TDP43 indicated role of TDP43 in disease pathology. Our findings suggest that there is oxidative insult and upregulation of UPR, vesicular trafficking and autophagy in PBMCs of sALS patients.
Subject(s)
Amyotrophic Lateral Sclerosis/pathology , Amyotrophic Lateral Sclerosis/physiopathology , Leukocytes, Mononuclear/metabolism , Proteostasis/physiology , Signal Transduction/physiology , Up-Regulation/physiology , Adult , Aged , Autophagy/physiology , Endoplasmic Reticulum Chaperone BiP , Endoplasmic Reticulum Stress/physiology , Female , Gene Expression/physiology , Heat-Shock Proteins/genetics , Heat-Shock Proteins/metabolism , Humans , Male , Middle Aged , Protein Carbonylation/physiology , Protein Unfolding , Ubiquitinated Proteins/genetics , Ubiquitinated Proteins/metabolism , X-Box Binding Protein 1/genetics , X-Box Binding Protein 1/metabolismABSTRACT
Pathogenic expansion of a hexanucleotide repeat in C9orf72 is associated with ~30% of familial ALS and ~7% of sporadic ALS patients amongst different populations. This repeat expansion was screened in 75 ALS patients and 115 healthy individuals from North India. On analysis by repeat-primed PCR, pathogenic expansion was not observed either in ALS patients or healthy controls. These observations are similar to the findings in most of the Asian populations.