title: Muscle magnetic resonance imaging and histopathology in ACTA1-related congenital nemaline myopathy.
abstract: BACKGROUND
  Muscle biopsy is usually diagnostic in nemaline myopathy (NM), but some patients may show nonspecific findings, leading to pitfalls in diagnosis. Muscle MRI is a helpful complementary tool.
  
  
  METHODS
  We assessed the clinical, histopathological, MRI, and molecular findings in a 19-year-old patient with NM in whom 2 muscle biopsies with ultrastructural examination showed no nemaline bodies. We analyzed the degree and pattern of muscle MRI involvement of the entire body, including the tongue and pectoral muscles.
  
  
  RESULTS
  Muscle MRI abnormalities in sartorius, adductor magnus, and anterior compartment muscles of the leg suggested NM. A previously unreported fatty infiltration of the tongue was found. A third biopsy after the muscle MRI showed scant nemaline bodies. A novel heterozygous de novo ACTA1 c.611C>T/p.Thr204Ile mutation was detected.
  
  
  CONCLUSIONS
  We highlight the contribution of muscle imaging in addressing the genetic diagnosis of ACTA1-related NM.
authors.affiliation: Unidad de Neurología. Departamento de Pediatría, Clínica las Condes, Lo Fontecilla 441, Las Condes, Santiago, Chile.
authors.forename: Claudia
authors.initials: C
authors.lastname: Castiglioni
authors.forename: Denis
authors.initials: D
authors.lastname: Cassandrini
authors.forename: Fabiana
authors.initials: F
authors.lastname: Fattori
authors.forename: Emanuele
authors.initials: E
authors.lastname: Bellacchio
authors.forename: Adele
authors.initials: A
authors.lastname: D'Amico
authors.forename: Karin
authors.initials: K
authors.lastname: Alvarez
authors.forename: Roger
authors.initials: R
authors.lastname: Gejman
authors.forename: Jorge
authors.initials: J
authors.lastname: Diaz
authors.forename: Filippo M
authors.initials: FM
authors.lastname: Santorelli
authors.forename: Norma B
authors.initials: NB
authors.lastname: Romero
authors.forename: Enrico
authors.initials: E
authors.lastname: Bertini
authors.forename: Jorge A
authors.initials: JA
authors.lastname: Bevilacqua
mesh_terms: D000199:Actins / Q000235:genetics; D001706:Biopsy; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D018482:Muscle, Skeletal / Q000473:pathology*; D009154:Mutation / Q000235:genetics; D017696:Myopathies, Nemaline / Q000175:diagnosis / Q000235:genetics* / Q000473:pathology*; D020914:Myopathies, Structural, Congenital; D055815:Young Adult
chemical_list: C541116:ACTA2 protein, human; D000199:Actins
keywords: ACTA1, congenital myopathy; nemaline myopathy; neurogenetics; type 1 fiber predominance; whole muscle MRI