MYH7 gene mutation in myosin storage myopathy and scapulo-peroneal myopathy.
In order to characterize, at the clinical, molecular and imaging level, myopathies due to MYH7 gene mutations, MYH7 gene analysis was conducted by RT-PCR/SSCP/sequencing in two patients diagnosed with myosin storage myopathy and 17 patients diagnosed with scapulo-peroneal myopathy of unknown etiology. MYH7 gene studies revealed the 5533C>T mutation (Arg1845Trp) in both myosin storage myopathy and in 2 of the 17 scapulo-peroneal patients studied. 5533C>T segregation analysis in the mutation carrier families identified 11 additional patients. The clinical spectrum in our cohort of patients included asymptomatic hyperCKemia, scapulo-peroneal myopathy and proximal and distal myopathy with muscle hypertrophy. Muscle MRI identified a unique pattern in the posterior compartment of the thigh, characterized by early involvement of the biceps femoris and semimembranosus, with relative sparing of the semitendinosus. Muscle biopsy revealed hyaline bodies in only half of biopsied patients (2/4). In conclusion, phenotypic and histopathological variability may underlie MYH7 gene mutation and the absence of hyaline bodies in muscle biopsies does not rule out MYH7 gene mutations.
Pegoraro
Elena
E
Department of Neurosciences, University of Padova, Italy. elena.pegoraro@unipd.it
Gavassini
Bruno F
BF
Borsato
Carlo
C
Melacini
Paola
P
Vianello
Andrea
A
Stramare
Roberto
R
Cenacchi
Giovanna
G
Angelini
Corrado
C
D000328:Adult; D000368:Aged; D001120:Arginine / Q000235:genetics; D024722:Cardiac Myosins / Q000235:genetics* / Q000378:metabolism; D002648:Child; D005192:Family Health; D005260:Female; D006801:Humans; D007223:Infant; D008279:Magnetic Resonance Imaging; D008297:Male; D046529:Microscopy, Electron, Transmission; D008875:Middle Aged; D018482:Muscle, Skeletal / Q000473:pathology / Q000648:ultrastructure; D009135:Muscular Diseases / Q000145:classification / Q000235:genetics* / Q000473:pathology; D020389:Muscular Dystrophy, Emery-Dreifuss / Q000235:genetics* / Q000473:pathology; D009154:Mutation; D018995:Myosin Heavy Chains / Q000235:genetics* / Q000378:metabolism; D009218:Myosins / Q000378:metabolism*; D012333:RNA, Messenger / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction / Q000379:methods; D014364:Tryptophan / Q000235:genetics
C501641:MYH7 protein, human; D012333:RNA, Messenger; D014364:Tryptophan; D001120:Arginine; D024722:Cardiac Myosins; D018995:Myosin Heavy Chains; D009218:Myosins