BACKGROUND: The acylcarnitine profiles obtained from dried blood spots on "Guthrie cards" have been widely used for the diagnosis and follow-up of children suspected of carrying an inherited error of metabolism, but little attention has been paid to potential age-related variations in the reference values. In this study, we evaluated the variations in free carnitine and acylcarnitine concentrations with age, as measured by tandem mass spectrometry. METHODS: Filter-paper blood spots were collected from 433 healthy individuals over a period of 17 months. Eight age groups were defined: cord blood, 3-6 days (control group), 15-55 days, 2-18 months, 19-59 months, 5-10 years, 11-17 years, and 18-54 years. Free carnitine and acylcarnitines were measured for each individual. Mean values were calculated for each age group and compared with those for the control group. RESULTS: Free carnitine was significantly higher in older children than in newborns (P <0.05), but the concentrations of several acylcarnitines tended to be significantly lower in cord blood and in groups of older children than in the control group. Only minor sex-related differences were observed. CONCLUSION: Although the risk of underdiagnosis of fatty acid oxidation disorders with the use of newborn values as reference can be considered as small, in some circumstances the use of age-related reference values may have a potential impact on the diagnosis and management of inherited errors of metabolism.
BACKGROUND: The acylcarnitine profiles obtained from dried blood spots on "Guthrie cards" have been widely used for the diagnosis and follow-up of children suspected of carrying an inherited error of metabolism, but little attention has been paid to potential age-related variations in the reference values. In this study, we evaluated the variations in free carnitine and acylcarnitine concentrations with age, as measured by tandem mass spectrometry. METHODS: Filter-paper blood spots were collected from 433 healthy individuals over a period of 17 months. Eight age groups were defined: cord blood, 3-6 days (control group), 15-55 days, 2-18 months, 19-59 months, 5-10 years, 11-17 years, and 18-54 years. Free carnitine and acylcarnitines were measured for each individual. Mean values were calculated for each age group and compared with those for the control group. RESULTS: Free carnitine was significantly higher in older children than in newborns (P <0.05), but the concentrations of several acylcarnitines tended to be significantly lower in cord blood and in groups of older children than in the control group. Only minor sex-related differences were observed. CONCLUSION: Although the risk of underdiagnosis of fatty acidoxidation disorders with the use of newborn values as reference can be considered as small, in some circumstances the use of age-related reference values may have a potential impact on the diagnosis and management of inherited errors of metabolism.
Authors: Ralph Fingerhut; Gabriel De Jesus Silva Arevalo; Matthias R Baumgartner; Johannes Häberle; Marianne Rohrbach; Andrés Weinfeld Ávalos Figueroa; Elena María Dardón Fresse; Olga Leticia Polanco; Toni Torresani Journal: J Inherit Metab Dis Date: 2010-07-21 Impact factor: 4.982
Authors: E Vieira Neto; A A Fonseca; R F Almeida; M P Figueiredo; M A S Porto; M G Ribeiro Journal: Braz J Med Biol Res Date: 2012-04-12 Impact factor: 2.590
Authors: Donna B Raval; Kristina P Cusmano-Ozog; Omar Ayyub; Callie Jenevein; Laura H Kofman; Brendan Lanpher; Natalie Hauser; Debra S Regier Journal: Mol Genet Metab Rep Date: 2016-12-09
Authors: Nora Céspedes; Angela Valencia; Carlos Alberto Echeverry; Maria Isabel Arce-Plata; Cristóbal Colón; Daisy E Castiñeiras; Paula Margarita Hurtado; Jose Angel Cocho; Sócrates Herrera; Myriam Arévalo-Herrera Journal: Colomb Med (Cali) Date: 2017-09-30