[Cap myopathy: a case report].
OBJECTIVE
To report a new case of a little-known congenital myopathy. Cap myopathy is a rare congenital disease caused by an alteration in the structure of the fibre, with disorganised myofibrils at the edges. Since it was first described, only a few cases have been reported in the literature.


METHODS
We describe the case of a 16-year-old patient with a history of neonatal hypotonia and psychomotor retardation. At the age of 4 years, the patient presented myopathic facies with atrophied pectoral muscles, winged scapula and lumbar hyperlordosis. A myopathic pattern was observed in the electromyogram. A muscle biopsy showed a very marked predominance of type I fibres, atrophy in part of the population of this type and 20% of them had cap-shaped subsarcolemmal accumulations, which were intensely positive with DPNH and SDH; in the ultrastructural study they correspond to disorganised peripheral myofibrils with preservation of the Z band and the absence of A bands. These alterations are similar to those described in what is known as cap disease or cap myopathy. Today, the patient has mild proximal tetraparesis and moderate restrictive respiratory failure.
Sección de Neuropatología, Departmento de Anatomía Patológica, Hospital Universitario 12 de Octubre, E-28045 Madrid, Espana. nuriamunozjareno@yahoo.es
N
N
Muñoz-Jareño
A
A
López-Martínez
D
D
Martín Fernández-Mayoralas
T
T
Meizoso-Latova
A
A
Cabello
D000015:Abnormalities, Multiple / Q000235:genetics; D018450:Disease Progression; D005152:Facial Muscles / Q000002:abnormalities; D005500:Follow-Up Studies; D006801:Humans; D007231:Infant, Newborn; D008607:Intellectual Disability / Q000235:genetics; D008297:Male; D018657:Muscle Fibers, Slow-Twitch / Q000201:enzymology / Q000473:pathology*; D009123:Muscle Hypotonia / Q000151:congenital* / Q000473:pathology; D009124:Muscle Proteins / Q000032:analysis; D018482:Muscle, Skeletal / Q000002:abnormalities* / Q000196:embryology / Q000201:enzymology / Q000473:pathology; D009133:Muscular Atrophy / Q000473:pathology; D009210:Myofibrils / Q000648:ultrastructure*; D011782:Quadriplegia / Q000209:etiology; D012131:Respiratory Insufficiency / Q000209:etiology; D012508:Sarcolemma / Q000648:ultrastructure; D013194:Staining and Labeling
D009124:Muscle Proteins