Lipid storage myopathy with normal carnitine levels.
A 28-year-old female, who showed a floppy baby syndrome during early infancy, had a non-progressive proximal muscle weakness with easy fatiguability since childhood. Two muscle specimens biopsied at the age of 28 years revealed myriads of 1-3-mum wide abnormal spaces containing neutral fat in type I and type II fibers.  Both biopsies demonstrated a type I fiber preponderance.  Electron microscopy demonstrated lipid excess and normal mitochondria by simple inspection. The mitochondrial area and sarcotubular membrane profile concentration in morphometry of longitudinal sections were also normal.  Cross-sections, however, revealed a slight decrease of the individual mitochondrial size and of the sarcotubular membrane profile concentration . Serum and muscle carnitine levels and the muscle carnitine palmityltransferase level were all within normal range.  Besides carnitine deficiency other biochemical defects can occur in lipid storage myopathy, which represents a syndrome rather than a unique disease entity.
D000123:Acetyltransferases / Q000032:analysis; D000135:Acid Phosphatase / Q000378:metabolism; D000251:Adenosine Triphosphatases / Q000378:metabolism; D000328:Adult; D002331:Carnitine / Q000097:blood* / Q000172:deficiency; D004576:Electromyography; D005260:Female; D006801:Humans; D050356:Lipid Metabolism; D008064:Lipidoses / Q000097:blood* / Q000201:enzymology / Q000378:metabolism / Q000473:pathology; D008297:Male; D008931:Mitochondria, Muscle / Q000648:ultrastructure; D009132:Muscles / Q000032:analysis / Q000201:enzymology / Q000378:metabolism / Q000648:ultrastructure; D009135:Muscular Diseases / Q000097:blood* / Q000201:enzymology / Q000378:metabolism / Q000473:pathology; D009210:Myofibrils / Q000201:enzymology; D009247:NADH, NADPH Oxidoreductases / Q000378:metabolism; D013577:Syndrome
D009247:NADH, NADPH Oxidoreductases; D000123:Acetyltransferases; D000135:Acid Phosphatase; D000251:Adenosine Triphosphatases; D002331:Carnitine