Genotype-phenotype correlations described
A huge study of 241 people with SPG7 has looked for links between their particular mutation type and physical factors such as age of onset, and presence or absence of particular symptoms such as spasticity, ataxia, muscle wasting, and speech and vision impairments.
Abstract
OBJECTIVE: We took advantage of a large multinational recruitment to delineate genotype-phenotype correlations in a large, trans-European multicenter cohort of patients with spastic paraplegia gene 7 (SPG7).
METHODS: We analyzed clinical and genetic data from 241 patients with SPG7, integrating neurologic follow-up data. One case was examined neuropathologically.
RESULTS: Patients with SPG7 had a mean age of 35.5 ± 14.3 years (n = 233) at onset and presented with spasticity (n = 89), ataxia (n = 74), or both (n = 45). At the first visit, patients with a longer disease duration (>20 years, n = 62) showed more cerebellar dysarthria (p < 0.05), deep sensory loss (p < 0.01), muscle wasting (p < 0.01), ophthalmoplegia (p < 0.05), and sphincter dysfunction (p < 0.05) than those with a shorter duration (<10 years, n = 93).
Progression, measured by Scale for the Assessment and Rating of Ataxia evaluations, showed a mean annual increase of 1.0 ± 1.4 points in a subgroup of 30 patients. Patients homozygous for loss of function (LOF) variants (n = 65) presented significantly more often with pyramidal signs (p < 0.05), diminished visual acuity due to optic atrophy (p < 0.0001), and deep sensory loss (p < 0.0001) than those with at least 1 missense variant (n = 176). Patients with at least 1 Ala510Val variant (58%) were older (age 37.6 ± 13.7 vs 32.8 ± 14.6 years, p < 0.05) and showed ataxia at onset (p < 0.05).
Neuropathologic examination revealed reduction of the pyramidal tract in the medulla oblongata and moderate loss of Purkinje cells and substantia nigra neurons.
CONCLUSIONS: This is the largest SPG7 cohort study to date and shows a spasticity-predominant phenotype of LOF variants and more frequent cerebellar ataxia; and later onset in patients carrying at least 1 Ala510Val variant.
SOURCE: Neurology. 2019 May 8. doi: 10.1212/WNL.0000000000007606. [Epub ahead of print] PMID: 31068484 © 2019 American Academy of Neurology.
Loss of paraplegin drives spasticity rather than ataxia in a cohort of 241 patients with SPG7.
Coarelli G1, Schule R1, van de Warrenburg BPC1, De Jonghe P1, Ewenczyk C1, Martinuzzi A1, Synofzik M1, Hamer EG1, Baets J1, Anheim M1, Schöls L1, Deconinck T1, Masrori P1, Fontaine B1, Klockgether T1, D’Angelo MG1, Monin ML1, De Bleecker J1, Migeotte I1, Charles P1, Bassi MT1, Klopstock T1, Mochel F1, Ollagnon-Roman E1, D’Hooghe M1, Kamm C1, Kurzwelly D1, Papin M1, Davoine CS1, Banneau G1, Tezenas du Montcel S1, Seilhean D1, Brice A1, Duyckaerts C1, Stevanin G1, Durr A2.
1 From Sorbonne Université (G.C., C.E., B.F., M.-L.M., F.M., M.P., C.-S.D., G.S., A.D.), Institut du Cerveau et de la Moelle épinière (ICM), AP-HP, INSERM, CNRS, University Hospital Pitié-Salpêtrière; Department of Genetics (G.C., C.E., M.-L.M., P.C., F.M., G.B., G.S., A.D.), Pitié-Salpêtrière Charles-Foix University Hospital, Assistance publique-Hôpitaux de Paris, Sorbonne Université, Paris, France; Center for Neurology and Hertie Institute for Clinical Brain Research (R.S., M.S., L.S.), University of Tübingen, German Center for Neurodegenerative Diseases; German Center for Neurodegenerative Diseases (R.S., M.S., L.S.), Tübingen; Department of Neurology (B.P.C.v.d.W., E.G.H.), Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, Nijmegen, the Netherlands; Neurogenetics Group (P.D.J., J.B., T.D., P.M., J.D.B., M.D.), University of Antwerp; Laboratories of Neurogenetics and Neuromuscular Pathology (P.D.J., J.B., T.D., P.M., J.D.B., M.D.), Institute Born-Bunge, University of Antwerp; Department of Neurology (P.D.J., J.B., T.D., P.M., J.D.B., M.D.), Antwerp University Hospital, Belgium; Scientific Institute IRCCS “E. Medea” (A.M.), Conegliano, Italy; Department of Neurology (M.A.), Hôpital de Hautepierre, Strasbourg; Institut de Génétique et de Biologie Moléculaire et Cellulaire (M.A.), INSERM-U964/CNRS-UMR7104/Université de Strasbourg, Illkirch; Fédération de Médecine Translationnelle de Strasbourg (M.A.), Université de Strasbourg; Department of Neurology (B.F.), Pitié-Salpêtrière Charles-Foix University Hospital, Assistance publique-Hôpitaux de Paris, Sorbonne Université, France; Department of Neurology (T. Klockgether, D.K.), University of Bonn; German Center for Neurodegenerative Diseases (T. Klockgether, D.K.), Bonn; Scientific Institute IRCCS E. Medea Neurorehabilitation Unit (M.G.D.), Bosisio Parini, Lecco, Italy; ULB Center of Human Genetics (I.M.), Brussels, Belgium; Scientific Institute IRCCS E. Medea Laboratory of Molecular Biology (M.T.B.), Bosisio Parini, Lecco, Italy; Department of Neurology With Friedrich-Baur Institute (T. Klopstock), University Hospital of the Ludwig-Maximilians-Universität München; German Center for Neurodegenerative Diseases (T. Klopstock); Munich Cluster for Systems Neurology (T. Klopstock), Germany; Department of Genetics (E.O.-R.), Croix-Rousse University Hospital, Lyon, France; Department of Neurology (C.K.), University of Rostock, Germany; Ecole Pratique des Hautes Etudes (M.P., G.S.), PSL Research University; Sorbonne Université (S.T.d.M.), INSERM, Institut Pierre Louis de Santé Publique, Medical Information Unit, Pitié-Salpêtrière Charles-Foix University Hospital, Assistance publique-Hôpitaux de Paris; and Raymond Escourolle Neuropathology Department (D.S., C.D.), Pitié-Salpêtrière University Hospital, Assistance publique-Hôpitaux de Paris, Sorbonne Université, France.
2 From Sorbonne Université (G.C., C.E., B.F., M.-L.M., F.M., M.P., C.-S.D., G.S., A.D.), Institut du Cerveau et de la Moelle épinière (ICM), AP-HP, INSERM, CNRS, University Hospital Pitié-Salpêtrière; Department of Genetics (G.C., C.E., M.-L.M., P.C., F.M., G.B., G.S., A.D.), Pitié-Salpêtrière Charles-Foix University Hospital, Assistance publique-Hôpitaux de Paris, Sorbonne Université, Paris, France; Center for Neurology and Hertie Institute for Clinical Brain Research (R.S., M.S., L.S.), University of Tübingen, German Center for Neurodegenerative Diseases; German Center for Neurodegenerative Diseases (R.S., M.S., L.S.), Tübingen; Department of Neurology (B.P.C.v.d.W., E.G.H.), Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, Nijmegen, the Netherlands; Neurogenetics Group (P.D.J., J.B., T.D., P.M., J.D.B., M.D.), University of Antwerp; Laboratories of Neurogenetics and Neuromuscular Pathology (P.D.J., J.B., T.D., P.M., J.D.B., M.D.), Institute Born-Bunge, University of Antwerp; Department of Neurology (P.D.J., J.B., T.D., P.M., J.D.B., M.D.), Antwerp University Hospital, Belgium; Scientific Institute IRCCS “E. Medea” (A.M.), Conegliano, Italy; Department of Neurology (M.A.), Hôpital de Hautepierre, Strasbourg; Institut de Génétique et de Biologie Moléculaire et Cellulaire (M.A.), INSERM-U964/CNRS-UMR7104/Université de Strasbourg, Illkirch; Fédération de Médecine Translationnelle de Strasbourg (M.A.), Université de Strasbourg; Department of Neurology (B.F.), Pitié-Salpêtrière Charles-Foix University Hospital, Assistance publique-Hôpitaux de Paris, Sorbonne Université, France; Department of Neurology (T. Klockgether, D.K.), University of Bonn; German Center for Neurodegenerative Diseases (T. Klockgether, D.K.), Bonn; Scientific Institute IRCCS E. Medea Neurorehabilitation Unit (M.G.D.), Bosisio Parini, Lecco, Italy; ULB Center of Human Genetics (I.M.), Brussels, Belgium; Scientific Institute IRCCS E. Medea Laboratory of Molecular Biology (M.T.B.), Bosisio Parini, Lecco, Italy; Department of Neurology With Friedrich-Baur Institute (T. Klopstock), University Hospital of the Ludwig-Maximilians-Universität München; German Center for Neurodegenerative Diseases (T. Klopstock); Munich Cluster for Systems Neurology (T. Klopstock), Germany; Department of Genetics (E.O.-R.), Croix-Rousse University Hospital, Lyon, France; Department of Neurology (C.K.), University of Rostock, Germany; Ecole Pratique des Hautes Etudes (M.P., G.S.), PSL Research University; Sorbonne Université (S.T.d.M.), INSERM, Institut Pierre Louis de Santé Publique, Medical Information Unit, Pitié-Salpêtrière Charles-Foix University Hospital, Assistance publique-Hôpitaux de Paris; and Raymond Escourolle Neuropathology Department (D.S., C.D.), Pitié-Salpêtrière University Hospital, Assistance publique-Hôpitaux de Paris, Sorbonne Université, France. [email protected].