Abstract
Primary carnitine deficiency (PCD) is an autosomal recessive disorder of fatty acid oxidation caused by mutations in the SLC22A5 gene encoding for the carnitine transporter OCTN2. Carnitine uptake deficiency results in renal carnitine wasting and low plasma levels. PCD usually presents early in life either with acute metabolic crisis or as progressive cardiomyopathy that responds to carnitine supplementation. PCD inclusion in the newborn screening (NBS) programs has led to the identification of asymptomatic adult patients ascertained because of a positive NBS in their offspring. We extensively reviewed the literature and found that 15 of 42 adult published cases (35.7%) were symptomatic. Cardiac arrhythmias were present in five patients (12%). Here, we report the ascertainment and long-term follow-up of the first case of PCD presenting with long QT syndrome. The patient presented in her early twenties with a syncopal episode caused by ventricular tachycardia, and a prolonged QT interval. Arrhythmias were poorly controlled by pharmacologic therapy and a defibrillator was installed. Syncopal episodes escalated during her first pregnancy. A positive NBS in the patient’s child suggested a carnitine uptake deficiency, which was confirmed by reduced carnitine transporter activity and by molecular testing. After starting carnitine supplementation, no further syncopal episodes have occurred and the QT interval returned to normal. As precaution, a low-dose metoprolol therapy and the defibrillator are still in place. Although rare, PCD should be ruled out as a cause of cardiac arrhythmias since oral carnitine supplementation is readily available and efficient.
Competing interests: None declared.
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References
Amat di San Filippo C, Taylor MR, Mestroni L, Botto LD, Longo N (2008) Cardiomyopathy and carnitine deficiency. Mol Genet Metab 94:162–166
El-Hattab AW, Li FY, Shen J et al (2010) Maternal systemic primary carnitine deficiency uncovered by newborn screening: clinical, biochemical, and molecular aspects. Genet Med 12:19–24
Labarthe F, Benoist JF, Peralta M, et al (2009) Primary carnitine uptake deficiency is associated with short QT syndrome and ventricular fibrillation. Poster 327 presented at the 11th international congress of inborn error of metabolism. Mol Genet Metab
Lee NC, Tang NL, Chien YH et al (2010) Diagnoses of newborns and mothers with carnitine uptake defects through newborn screening. Mol Genet Metab 100:46–50
Li FY, El-Hattab AW, Bawle EV et al (2010) Molecular spectrum of SLC22A5 (OCTN2) gene mutations detected in 143 subjects evaluated for systemic carnitine deficiency. Hum Mutat 31:E1632–E1651
Lund AM, Joensen F, Hougaard DM et al (2007) Carnitine transporter and holocarboxylase synthetase deficiencies in the Faroe Islands. J Inherit Metab Dis 30:341–349
Nezu J, Tamai I, Oku A et al (1999) Primary systemic carnitine deficiency is caused by mutations in a gene encoding sodium ion-dependent carnitine transporter. Nat Genet 21:91–94
Sarafoglou K, Tridgell AH, Bentler K, Redlinger-Grosse K, Berry SA, Schimmenti LA (2010) Cardiac conduction improvement in two heterozygotes for primary carnitine deficiency on L-carnitine supplementation. Clin Genet 78:191–194
Schimmenti LA, Crombez EA, Schwahn BC et al (2007) Expanded newborn screening identifies maternal primary carnitine deficiency. Mol Genet Metab 90:441–445
Spiekerkoetter U, Huener G, Baykal T et al (2003) Silent and symptomatic primary carnitine deficiency within the same family due to identical mutations in the organic cation/carnitine transporter OCTN2. J Inherit Metab Dis 26:613–615
Stanley CA, DeLeeuw S, Coates PM et al (1991) Chronic cardiomyopathy and weakness or acute coma in children with a defect in carnitine uptake. Ann Neurol 30:709–716
Vijay S, Patterson A, Olpin S et al (2006) Carnitine transporter defect: diagnosis in asymptomatic adult women following analysis of acylcarnitines in their newborn infants. J Inherit Metab Dis 29:627–630
Wilcken B, Wivoley V, Hammond J, Carpenter K (2003) Screening newborns for inborn errors of metabolism by tandem mass spectrometry. N Engl J Med 348:2304–2312
Acknowledgment
We thank the Greenwood Genetic Center metabolic team for the help during our patient follow up. We also thank Dr. Roger Stevenson for the helpful comments and for editing the manuscript. Dr. Nicola Longo is supported by grant R01-DK053824 from the National Institute of Diabetes And Digestive And Kidney Diseases.
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Communicated by: Jerry Vockley.
Synopsis
Synopsis
The ascertainment and the 5-year follow up are described for an adult case of PCD presenting atypically with long QT syndrome successfully treated with carnitine supplementation.
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© 2011 SSIEM and Springer-Verlag Berlin Heidelberg
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De Biase, I., Champaigne, N.L., Schroer, R., Pollard, L.M., Longo, N., Wood, T. (2011). Primary Carnitine Deficiency Presents Atypically with Long QT Syndrome: A Case Report. In: JIMD Reports - Case and Research Reports, 2011/2. JIMD Reports, vol 2. Springer, Berlin, Heidelberg. https://doi.org/10.1007/8904_2011_52
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DOI: https://doi.org/10.1007/8904_2011_52
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