title: Magnetic resonance imaging of muscle in congenital myopathies associated with RYR1 mutations.
abstract: Mutations in the skeletal muscle ryanodine receptor (RYR1) gene are associated with a wide range of phenotypes, comprising central core disease and distinct subgroups of multi-minicore disease. We report muscle MRI findings of 11 patients from eight families with RYR1 mutations (n=9) or confirmed linkage to the RYR1 locus (n=2). Patients had clinical features of a congenital myopathy with a wide variety of associated histopathological changes. Muscle MR images showed a consistent pattern characterized by (a) within the thigh: selective involvement of vasti, sartorius, adductor magnus and relative sparing of rectus, gracilis and adductor longus; (b) within the lower leg: selective involvement of soleus, gastrocnemii and peroneal group and relative sparing of the tibialis anterior. Our findings indicate that patients with RYR1-related congenital myopathies have a recognizable pattern of muscle involvement irrespective of the variability of associated histopathological findings. Muscle MRI may supplement clinical assessment and aid selection of genetic tests particularly in patients with non-diagnostic or equivocal histopathological features.
authors.affiliation: Department of Paediatric Neurology, Guy's Hospital, London, UK. h.jungbluth@imperial.ac.uk
authors.forename: Heinz
authors.initials: H
authors.lastname: Jungbluth
authors.forename: Mark R
authors.initials: MR
authors.lastname: Davis
authors.forename: Clemens
authors.initials: C
authors.lastname: Müller
authors.forename: Serena
authors.initials: S
authors.lastname: Counsell
authors.forename: Joanna
authors.initials: J
authors.lastname: Allsop
authors.forename: Arijit
authors.initials: A
authors.lastname: Chattopadhyay
authors.forename: Sonia
authors.initials: S
authors.lastname: Messina
authors.forename: Eugenio
authors.initials: E
authors.lastname: Mercuri
authors.forename: Nigel G
authors.initials: NG
authors.lastname: Laing
authors.forename: Caroline A
authors.initials: CA
authors.lastname: Sewry
authors.forename: Graeme
authors.initials: G
authors.lastname: Bydder
authors.forename: Francesco
authors.initials: F
authors.lastname: Muntoni
mesh_terms: D000293:Adolescent; D000328:Adult; D002648:Child; D002675:Child, Preschool; D004252:DNA Mutational Analysis; D003937:Diagnosis, Differential; D005260:Female; D020022:Genetic Predisposition to Disease / Q000235:genetics*; D005820:Genetic Testing; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D018482:Muscle, Skeletal / Q000378:metabolism / Q000473:pathology* / Q000503:physiopathology; D009154:Mutation / Q000235:genetics*; D020914:Myopathies, Structural, Congenital / Q000235:genetics* / Q000473:pathology*; D020512:Myopathy, Central Core / Q000235:genetics / Q000473:pathology; D019683:Penetrance; D010641:Phenotype; D011237:Predictive Value of Tests; D019837:Ryanodine Receptor Calcium Release Channel / Q000235:genetics*; D013848:Thigh / Q000473:pathology
chemical_list: D019837:Ryanodine Receptor Calcium Release Channel