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Plasma carnitine ester profile in homozygous and heterozygous OCTN2 deficiency
Author(s) -
Komlósi K.,
Magyari L.,
Talián G. C.,
Nemes É.,
Káposzta R.,
Mogyorósy G.,
Méhes K.,
Melegh B.
Publication year - 2009
Publication title -
journal of inherited metabolic disease
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.462
H-Index - 102
eISSN - 1573-2665
pISSN - 0141-8955
DOI - 10.1007/s10545-009-0926-1
Subject(s) - carnitine , endocrinology , heterozygote advantage , human genetics , medicine , metabolic disease , chemistry , genetics , biology , gene , genotype
Summary The carnitine ester spectrum was studied using ESI tandem mass spectrometry in a 2.5‐year‐old male Roma child with homozygous deletion of 844C of the SLC22A5 gene, presenting with hepatopathy and cardiomyopathy. Besides the dramatic decrease of plasma free carnitine (1.38 vs 32.7 μmol/L in controls) all plasma carnitine esters were severely decreased in the proband: the total esters were 31.4% of the controls. In three heterozygous siblings the free carnitine level was 62.3% of the normal controls, while the levels of the individual carnitine esters ranged between 15.5% and 163% (average 70.9%). The heterozygous parents exhibited the same pattern. The proband was supplemented with 50 mg/kg per day of l ‐carnitine oral solution. After 2 months of treatment, his hepatomegaly, elevated transaminases and the pathological cardiac ultrasound parameters normalized. The plasma free carnitine rose to 12.8 μmol/L (39% of the controls). All of the carnitine esters also increased; however, the individual esters were still 8.5–169.7% of the controls (average 55.5%). After 13 months of treatment there was a further increase in free carnitine (15.9 μmol/L) as well as in the level of the individual esters, ranging between 16.1% and 140.3% of the controls (average 66.9%). The data presented here show that, besides the dramatic decrease of free carnitine, the carnitine ester metabolism is also affected in OCTN2 deficiency; the replenishment of the pools under treatment is slow. Despite an impressive clinical improvement, the carnitine metabolism can be still seriously affected.