Primary Carnitine (OCTN2) Deficiency Without Neonatal Carnitine Deficiency.

ABSTRACT: Although the diagnosis of a primary carnitine deficiency is usually based on a very low level of free and total carnitine (free carnitine: 1-5 ?M, normal 20-55 ?M) (Longo et al. 2006), we detected a patient via newborn screening with a total carnitine level 67 % of the normal value. At the age of 1 year, after interruption of carnitine supplementation for a 4-week period the carnitine profile was assessed and the free carnitine level had dropped to 10.4 ?mol/l (normal: 20-55 ?M) and total carnitine level had dropped to 12.7 ?mol/l (normal: 25-65 ?M). Transient carnitine deficiency was not likely anymore and DNA mutation analysis of the OCTN2 (SLC22A5) gene showed a homozygous c.136C>T (p.P46S) mutation, confirming the diagnosis of primary carnitine deficiency. We would like to emphasize that neonates with a primary carnitine deficiency might present with relatively high levels of total carnitine due to placental carnitine transfer, and also draw the attention to the importance of regular follow-up and the significance of genetic diagnostics in patients with a nonclassical presentation.

SUBMITTER: de Boer L 

PROVIDER: S-EPMC3755582 | biostudies-literature | 2013

REPOSITORIES: biostudies-literature