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Neurology. 2015 Feb 17;84(7):668-79. doi: 10.1212/WNL.0000000000001269. Epub 2015 Jan 21.

Novel mutations expand the clinical spectrum of DYNC1H1-associated spinal muscular atrophy.

Author information

1
From the Dubowitz Neuromuscular Center (M.S., M.C., S.R., A.Y.M., A.R.F., C.S., R.P., F.M.) and MRC Center for Neuromuscular Diseases (F.M.), UCL Institute of Child Health, London; MRC Center for Neuromuscular Diseases (A.M.R., M.M.R.), UCL Institute of Neurology, Queen Square, London, UK; Neuromuscular Division (M.B.H., A.M.C., M.T.A.-L.), Department of Neurology, Washington University School of Medicine, St. Louis, MO; Research Center for Genetic Medicine (S.C.), Children's National Medical Center, Washington, DC; Galdakao-Usansolo Hospital (A.M.A., A.R.S.), Department of Neurology, Barrio Labeaga s/n, Usansolo, Vizcaya, Spain; St George's NHS Health Care Trust (S.M., P.F., I.H.), London, UK; Department of Paediatric Neurology (A.K.), University Children's Hospital, Zurich, Switzerland; Department of Pediatrics (M.Y.), University of Colorado Denver; Department of Neurology (M.D.V., W.C.G.O.-P., F.B.), Academic Medical Center, University of Amsterdam, the Netherlands; Human Genetics Unit (C.M.), Ninewells Hospital, Dundee; Center for Inherited Neuromuscular Diseases (C.S.), RJAH Orthopaedic NHS Foundation Trust, Oswestry; School of Life Sciences (M.H.), University of Sussex, John Maynard Smith Building, Brighton; Radiology Department (W.K.C.) and Neurophysiology Department (M.P.), Great Ormond Street Hospital, London, UK; Paediatric Neurology Unit (E.M.), Policlinico Gemelli, Rome, Italy; Department of Neurology (R.H.B.), Cedars Sinai Medical Center, Los Angeles, CA; Department of Developmental Neurobiology (J.P.T.), St. Jude Children's Research Hospital, Memphis, TN; Neurology Department (M.B.), University of Miami Miller School of Medicine, FL; and Department of Neurology (J.N., C.G.E.L.d.G.), Royal Preston Hospital, UK.
2
From the Dubowitz Neuromuscular Center (M.S., M.C., S.R., A.Y.M., A.R.F., C.S., R.P., F.M.) and MRC Center for Neuromuscular Diseases (F.M.), UCL Institute of Child Health, London; MRC Center for Neuromuscular Diseases (A.M.R., M.M.R.), UCL Institute of Neurology, Queen Square, London, UK; Neuromuscular Division (M.B.H., A.M.C., M.T.A.-L.), Department of Neurology, Washington University School of Medicine, St. Louis, MO; Research Center for Genetic Medicine (S.C.), Children's National Medical Center, Washington, DC; Galdakao-Usansolo Hospital (A.M.A., A.R.S.), Department of Neurology, Barrio Labeaga s/n, Usansolo, Vizcaya, Spain; St George's NHS Health Care Trust (S.M., P.F., I.H.), London, UK; Department of Paediatric Neurology (A.K.), University Children's Hospital, Zurich, Switzerland; Department of Pediatrics (M.Y.), University of Colorado Denver; Department of Neurology (M.D.V., W.C.G.O.-P., F.B.), Academic Medical Center, University of Amsterdam, the Netherlands; Human Genetics Unit (C.M.), Ninewells Hospital, Dundee; Center for Inherited Neuromuscular Diseases (C.S.), RJAH Orthopaedic NHS Foundation Trust, Oswestry; School of Life Sciences (M.H.), University of Sussex, John Maynard Smith Building, Brighton; Radiology Department (W.K.C.) and Neurophysiology Department (M.P.), Great Ormond Street Hospital, London, UK; Paediatric Neurology Unit (E.M.), Policlinico Gemelli, Rome, Italy; Department of Neurology (R.H.B.), Cedars Sinai Medical Center, Los Angeles, CA; Department of Developmental Neurobiology (J.P.T.), St. Jude Children's Research Hospital, Memphis, TN; Neurology Department (M.B.), University of Miami Miller School of Medicine, FL; and Department of Neurology (J.N., C.G.E.L.d.G.), Royal Preston Hospital, UK. f.muntoni@ucl.ac.uk.

Abstract

OBJECTIVE:

To expand the clinical phenotype of autosomal dominant congenital spinal muscular atrophy with lower extremity predominance (SMA-LED) due to mutations in the dynein, cytoplasmic 1, heavy chain 1 (DYNC1H1) gene.

METHODS:

Patients with a phenotype suggestive of a motor, non-length-dependent neuronopathy predominantly affecting the lower limbs were identified at participating neuromuscular centers and referred for targeted sequencing of DYNC1H1.

RESULTS:

We report a cohort of 30 cases of SMA-LED from 16 families, carrying mutations in the tail and motor domains of DYNC1H1, including 10 novel mutations. These patients are characterized by congenital or childhood-onset lower limb wasting and weakness frequently associated with cognitive impairment. The clinical severity is variable, ranging from generalized arthrogryposis and inability to ambulate to exclusive and mild lower limb weakness. In many individuals with cognitive impairment (9/30 had cognitive impairment) who underwent brain MRI, there was an underlying structural malformation resulting in polymicrogyric appearance. The lower limb muscle MRI shows a distinctive pattern suggestive of denervation characterized by sparing and relative hypertrophy of the adductor longus and semitendinosus muscles at the thigh level, and diffuse involvement with relative sparing of the anterior-medial muscles at the calf level. Proximal muscle histopathology did not always show classic neurogenic features.

CONCLUSION:

Our report expands the clinical spectrum of DYNC1H1-related SMA-LED to include generalized arthrogryposis. In addition, we report that the neurogenic peripheral pathology and the CNS neuronal migration defects are often associated, reinforcing the importance of DYNC1H1 in both central and peripheral neuronal functions.

PMID:
25609763
PMCID:
PMC4336105
DOI:
10.1212/WNL.0000000000001269
[Indexed for MEDLINE]
Free PMC Article

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