Congenital and metabolic myopathies of childhood or adult onset.
OBJECTIVE
To investigate the clinical presentation, histological findings, and outcome of patients with congenital and metabolic myopathies (CM and MM) in whom the disease was diagnosed in childhood or adulthood.


METHODS
We reviewed the diagnosis of all skeletal muscle biopsies performed by our group between 1984 and 1996 (13 years). All patients with CM and MM of childhood or adult onset were included in the study. Patients with mitochondrial myopathies were excluded because they are multisystemic disorders with a more distinct picture than that observed in other MM. We retrospectively reviewed the clinical history, with special emphasis on the clinical patterns of presentation, histological findings, and outcome.


RESULTS
Among 1,865 biopsies, 28 (1.5%) fulfilled the diagnostic criteria for CM (seven nemaline myopathies, four multicore myopathies, three centronuclear myopathies) or MM (five adult-onset acid maltase deficiency, three myophosphorylase deficiency, three phosphofructokinase deficiency, two carnitine palmitoyl transferase deficiency, and one carnitine deficiency). In nearly half of the patients, mild stable weakness was the major complaint, whereas in one third muscular symptoms were intermittent and related to exercise. In a small number of cases, a persistently raised serum creatine kinase in an asymptomatic patient was the reason for muscle biopsy. Histological examination of skeletal muscle was highly indicative of a specific muscle disease in 26 of the 28 cases. After a mean follow-up of 7 years, the outcome has generally been good, and in most patients the myopathy did not worsen, most remaining ambulatory.


CONCLUSIONS
CM and MM presenting in childhood or adulthood are infrequent; the symptoms are usually mild or moderate, and the prognosis generally is good.
Department of Internal Medicine, Hospital Clínic, August Pi i Sunyer Biomedical Research Institute, Medical School, University of Barcelona, Catalonia, Spain.
O
O
Miró
M
M
Laguno
F
F
Masanés
M
M
Perea
A
A
Urbano-Márquez
J M
JM
Grau
D000293:Adolescent; D000328:Adult; D017668:Age of Onset; D000368:Aged; D001706:Biopsy; D002331:Carnitine / Q000172:deficiency; D002334:Carnitine O-Palmitoyltransferase / Q000172:deficiency; D002648:Child; D002675:Child, Preschool; D003402:Creatine Kinase / Q000097:blood; D005260:Female; D005500:Follow-Up Studies; D006014:Glycogen Storage Disease Type VII / Q000378:metabolism / Q000473:pathology; D006801:Humans; D008297:Male; D008854:Microscopy, Electron; D008875:Middle Aged; D018485:Muscle Fibers, Skeletal / Q000201:enzymology / Q000473:pathology / Q000648:ultrastructure; D018482:Muscle, Skeletal / Q000201:enzymology / Q000473:pathology*; D020966:Muscular Disorders, Atrophic / Q000151:congenital / Q000378:metabolism / Q000473:pathology*; D017696:Myopathies, Nemaline / Q000378:metabolism / Q000473:pathology*; D006005:Phosphorylases / Q000172:deficiency; D011379:Prognosis; D020127:Recovery of Function; D012189:Retrospective Studies; D000520:alpha-Glucosidases / Q000172:deficiency
D002334:Carnitine O-Palmitoyltransferase; D006005:Phosphorylases; D003402:Creatine Kinase; D000520:alpha-Glucosidases; D002331:Carnitine