Carnitine “deficiency”

Abstract

A 29-year-old women had muscle weakness, low concentrations of carnitine in muscle and serum, and abnormally low urinary excretion of carnitine. During a fast, exercise capacity declined, ketone body concentrations rose, metabolic acidosis worsened, and she became hypoglycemic. After treatment with oral carnitine, serum carnitine content returned to normal and blood glucose was maintained during fasting, but ketone body concentrations in blood were even higher. Muscle carnitine content and exercise capacity did not improve. This patient demonstrated features of both systemic and muscle carnitine deficiency, suggesting that the current classification of carnitine-deficiency syndromes is inadequate.

Primary carnitine deficiency: adult onset lipid storage myopathy with a mild clinical course

“…19 Responses to L L-carnitine administration are reported by some authors 18,20-25 but not by others. 19,26,27 Furthermore, in some reported cases the effects of L L-carnitine on muscular lipid content were not verified by a post-treatment control muscle biopsy 22 and even more importantly, functional mitochondrial respiratory chain studies were not carried out despite description of ultrastructural mitochondrial abnormalities including paracrystalline inclusions 18,22 and the persistence of ragged red fibres after carnitine therapy. 18 Lipid storage myopathies with ragged red fibres 19 or cytochrome c oxidase deficiency 6,28 are suggestive of a respiratory chain defect with a putative secondary carnitine deficiency.…”

Familial carnitine deficiency: further evidence for autosomal recessive transmission with variable expression.

“…[5][6][7][8] Familial carnitine deficiency has been rarely reported,9'l describing marked heterogeneity of carnitine deficiency states, thus postulating an autosomal recessive mode of transmission. We have studied five members of one family who had various forms of carnitine deficiency.…”