Pseudo-metabolic presentation in a Duchenne muscular dystrophy symptomatic carrier with 'de novo' duplication of dystrophin gene.
We report a 6-year-old female patient presenting with a sudden and severe single episode of rhabdomyolysis in which screening for a metabolic disorder was negative. Four months after the episode a muscle biopsy was performed and showed a mild pattern of necrosis/regeneration. Upon immunofluorescence, a mosaic pattern of dystrophin deficiency was found, and in the dystrophin deficient muscle fibres, the four proteins of the sarcoglycan complex were also lacking. Genetic analysis showed a duplication of exons 3 to 17 on one X-chromosome of the proband, but not on the mother's X-chromosome. A clearly skewed X-inactivation (85% of the defective X being active) was found and is consistent with the patient being symptomatic. To our knowledge, a spontaneous rhabdomyolysis in a female Duchenne muscular dystrophy carrier has never been reported.
Romero
N B
NB
INSERM U523 and Institut de Myologie, Hôpital de la Salpêtrière; 47 Boulevard de l'Hôpital, 75013, Paris, France. nb.romero@myologie.chups.jussieu.fr
De Lonlay
P
P
Llense
S
S
Leturcq
F
F
Touati
G
G
Urtizberea
J A
JA
Saudubray
J M
JM
Munnich
A
A
Kaplan
J C
JC
Récan
D
D
D001706:Biopsy; D002648:Child; D004303:Dosage Compensation, Genetic; D016189:Dystrophin / Q000235:genetics*; D005260:Female; D020131:Genes, Duplicate; D006579:Heterozygote; D006801:Humans; D020388:Muscular Dystrophy, Duchenne / Q000235:genetics* / Q000378:metabolism / Q000473:pathology*; D012206:Rhabdomyolysis / Q000235:genetics / Q000378:metabolism / Q000473:pathology; D014960:X Chromosome
D016189:Dystrophin