Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UNIPROT:Q16637 (SMA)
 8,107 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

In the present study, we report a single Polish SMA family in which the 17p11.2-p12 duplication causative for the Charcot-Marie-Tooth type 1A disease (CMT1A) was found in addition to a deletion of exons 7 and 8 of the SMN1 gene. A patient harboring both SMA and CMT1A mutations manifested with SMA3 phenotype and foot deformity. Her electrophysiological testing showed chronic neurogenic changes in proximal muscles that are typical for SMA, but also slowed conduction velocity in motor and sensory fibers that is typical for demyelinating neuropathy.
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PMID:A patient with both Charcot-Marie-Tooth disease (CMT 1A) and mild spinal muscular atrophy (SMA 3). 1833 1

Mutations in the DYNC1H1 gene encoding for dynein heavy chain cause two closely related human motor neuropathies, dominant spinal muscular atrophy with lower extremity predominance (SMA-LED) and axonal Charcot-Marie-Tooth (CMT) disease, and lead to sensory neuropathy and striatal atrophy in mutant mice. Dynein is the molecular motor carrying mitochondria retrogradely on microtubules, yet the consequences of dynein mutations on mitochondrial physiology have not been explored. Here, we show that mouse fibroblasts bearing heterozygous or homozygous point mutation in Dync1h1, similar to human mutations, show profoundly abnormal mitochondrial morphology associated with the loss of mitofusin 1. Furthermore, heterozygous Dync1h1 mutant mice display progressive mitochondrial dysfunction in muscle and mitochondria progressively increase in size and invade sarcomeres. As a likely consequence of systemic mitochondrial dysfunction, Dync1h1 mutant mice develop hyperinsulinemia and hyperglycemia and progress to glucose intolerance with age. Similar defects in mitochondrial morphology and mitofusin levels are observed in fibroblasts from patients with SMA-LED. Last, we show that Dync1h1 mutant fibroblasts show impaired perinuclear clustering of mitochondria in response to mitochondrial uncoupling. Our results show that dynein function is required for the maintenance of mitochondrial morphology and function with aging and suggest that mitochondrial dysfunction contributes to dynein-dependent neurological diseases, such as SMA-LED.
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PMID:Dynein mutations associated with hereditary motor neuropathies impair mitochondrial morphology and function with age. 2374 62

Neurons are highly specialized for the processing and transmission of electrical signals and use cytoskeleton-based motor proteins to transport different vesicles and cellular materials. Abnormalities in intracellular transport are thought to be a critical factor in the degeneration and death of neurons in both the central and peripheral nervous systems. Several recent studies describe disruptive mutations in the minus-end-directed microtubule motor cytoplasmic dynein that are directly linked to human motor neuropathies, such as SMA (spinal muscular atrophy) and axonal CMT (Charcot-Marie-Tooth) disease or malformations of cortical development, including lissencephaly, pachygyria and polymicrogyria. In addition, genetic defects associated with these and other neurological disorders have been found in multifunctional adaptors that regulate dynein function, including the dynactin subunit p150(Glued), BICD2 (Bicaudal D2), Lis-1 (lissencephaly 1) and NDE1 (nuclear distribution protein E). In the present paper we provide an overview of the disease-causing mutations in dynein motors and regulatory proteins that lead to a broad phenotypic spectrum extending from peripheral neuropathies to cerebral malformations.
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PMID:Mutations in cytoplasmic dynein and its regulators cause malformations of cortical development and neurodegenerative diseases. 2425 62

Following the completion of the Human Genome Project, a lot of progress has been made in understanding the genetic basis of motor neuron diseases (MNDs) and neuropathies. Spinal Muscular Atrophies (SMA) are caused by mutations in the SMN1 gene localized on Chromosome 5q11. Amyotrophic Lateral Sclerosis (ALS) has been found to have at least 18 different types, many of them associated to different genetic loci (e.g. SOD1, ALS2, SETX, FUS, VAPB, ANG, TARDBP and others), but many of the forms have still not been associated with a particular gene. Sensomotoric hereditary neuropathies (Charcot-Marie-Tooth) are a large heterogeneous group of various hereditary neuropathies, which have also been associated with a wide spectrum of genetic mutations, such as PMP22, LITAF, EGR2, P0 protein, KIF1B, MFN2, RAB7 and others. It is also apparent that more genes are being implicated, mutations discovered, and phenotypes recognised and broadened. Therefore, a lot of continuing, additional research effort will be required in the coming years to illuminate pathogenic mechanisms that underlie motor neuron diseases and neuropathies and that could lead to new and improved treatments.
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PMID:Genetic determination of motor neuron disease and neuropathy. 2604 Jan 3