title: Type I spinal muscular atrophy can mimic sensory-motor axonal neuropathy.
abstract: Spinal muscular atrophy is a group of allelic autosomal recessive disorders characterized by progressive motoneuron loss, symmetric weakness, and skeletal muscle atrophy. It is traditionally considered a pure lower motoneuron disorder, for which a current definitive diagnosis is now possible by molecular genetic testing. We report two newborns with a clinical phenotype consistent with that of spinal muscular atrophy type I and nerve conduction studies and electromyography suggesting more extensive sensory involvement than classically described with spinal muscular atrophy. Molecular testing confirmed spinal muscular atrophy in patient 1 but not in patient 2. Thus, in the setting of a suspected congenital axonal neuropathy, molecular testing might be necessary to distinguish spinal muscular atrophy type I from infantile polyneuropathy.
authors.affiliation: Division of Pediatric Neurology, Montreal Children's Hospital, Department of Neurology, McGill University, Montreal, Quebec.
authors.forename: Evdokia
authors.initials: E
authors.lastname: Anagnostou
authors.forename: Steven P
authors.initials: SP
authors.lastname: Miller
authors.forename: Marie-Christine
authors.initials: MC
authors.lastname: Guiot
authors.forename: Greoge
authors.initials: G
authors.lastname: Karpati
authors.forename: Louise
authors.initials: L
authors.lastname: Simard
authors.forename: Marie-Emmanuelle
authors.initials: ME
authors.lastname: Dilenge
authors.forename: Michael I
authors.initials: MI
authors.lastname: Shevell
mesh_terms: D003937:Diagnosis, Differential; D015417:Hereditary Sensory and Motor Neuropathy / Q000473:pathology* / Q000503:physiopathology*; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D009431:Neural Conduction / Q000502:physiology; D014897:Spinal Muscular Atrophies of Childhood / Q000235:genetics / Q000473:pathology* / Q000503:physiopathology*; D013127:Spinal Nerves / Q000473:pathology / Q000503:physiopathology