ABSTRACT
INTRODUCTION@#Acylcarnitines in plasma and urinary organic acids are essential diagnostic markers for some Inborn Errors of Metabolism (IEM) such as fatty acid oxidation disorders, and disorders related to organic acids metabolism. By virtue of R. A. 9288, Filipino newborn babies are screened for inherited metabolic disorders via the analysis of dried blood spots (DBS) using MS/MS. @*OBJECTIVE@#This study aimed to establish the plasma acylcarnitine (PLAC) and urinary organic acid (UOA) profiles of Filipino newborn babies screened at high risk for IEMS using MS/MS and single quadrupole GC-MS analytical techniques. Further, this study describes the process of determining the true positive cases of fatty acid oxidation disorders and some organic acidurias among screened Filipino newborn babies using different sample types such as plasma and urine via flow injection analysis with tandem mass spectrometry (FIA-MS/MS) and another technique such as gas chromatography in tandem with mass spectrometry (GC-MS).@*METHODOLOGY@#Plasma acylcarnitine and urinary organic acid analyses were performed using Waters® MS/MS and Agilent® single quadrupole GC-MS, respectively. Results obtained from PLAC and UOA databases and IEM registry of the Biochemical Genetics Laboratory (BGL) covering the period 2015-2021 were utilized to account for the number of confirmed cases out of the total number screened positive for IEMs. Descriptive statistics was also used to evaluate the detection rates of FAODs and Organic Acidurias in Filipino newborn babies screened to be high risk.@*RESULTS@#Plasma acylcarnitine analysis was introduced by BGL only in 2015. Data from 2015-2021, indicated 176 true positives out of 1642 babies screened at high risk for FAODs and organic acidurias. The use of plasma and urine samples for measurements in MS/MS and GC-MS yielded a detection rate of 10.7% with 104 Filipino newborn babies afflicted with fatty acid oxidation disorders (FAOD) while 72 were found to be confirmed cases of organic acidurias. Medium-chain acyl-CoA dehydrogenase (MCAD) deficiency was reported to be the most common FAOD with 67 cases. Organic acidurias such as glutaric aciduria type 1 and 3-Methylcrotonyl-CoA carboxylase (3-MCC) deficiency were found to be common with 34 and 26 true positives, respectively. @*CONCLUSION@#The plasma acylcarnitine and urinary organic acid profiles of Filipino newborn babies with fatty acid oxidation disorders and organic acidurias obtained via MS/MS and GC/MS, respectively, were presented in this paper. This study emphasizes the importance of conducting confirmatory testing to establish the true positives from among those Filipino newborns flagged to be at high risk for FAODs or organic aciduria. The confirmatory tests are based on the use of different samples such as urine and plasma in order to detect and quantify biomarkers for FAODs and organic acidurias using two different analytical techniques such as MS/MS and GC-MS. This study warrants further studies directed towards the validation of analytical methodologies for targeted measurements of biomarkers of IEMS in urine and plasma of newborn babies to increase the efficiency of establishing true positives and to determine the efficiency of administration of interventions on Filipino children with genetic disabilities, that is, for monitoring purposes.
Subject(s)
Plasma , Tandem Mass SpectrometryABSTRACT
Mitochondrial fatty acid β-oxidation defects are series of underlying fatal diseases. The enzyme deficiencies caused by related gene mutations would lead to energy metabolic crisis and multi-organ damage. The clinical features of the patients are varied. The disease course ranged from acute to chronic,with mild to severe symptoms. Some previously healthy patients presented as sudden unexpected death due to acute cardiac death. With the development and the application of biochemical and genetic technologies in the metabolic autopsy,mitochondrial fatty acid β-oxidation disorders were recognized to be the genetic cause of sudden death. By expanded neonatal screening using tandem mass spectrometry,the patients could be detected at asymptomatic period or early stage of disease. Early intervention is the key to reduce the mortality and the disability.
ABSTRACT
myocardium. Fatty acid oxidation disorders(FAODs)can give rise to insufficiency of mitochondrial energy production and accumulation of metabolic intermediates in cardiomyocytes,such as lipid and long-chain acyl carnitine,leading to myocardial lesions.FAODs include carnitine-dependent fatty acid transport disorders and mitochondrial fatty acid beta-oxidation disorders,with any enzyme or transporter defect in fatty acid oxidation process resulting in this disease. Although FAODs are one of the rare causes of pediatric cardiomyopathy,some patients with FAODs are expected to have cardiomyopathy alleviated and quality of life improved by early correction of fatty acid metabolic disorders.
ABSTRACT
Primary carnitine deficiency is an autosomal recessive hereditary disease caused by the mutation of SLC22 A5 gene,which leads to increased carnitine excretion in urine and low level of carnitine in blood,tissues and cells. Due to the heterogeneity and non-specificity of the clinical manifestations of PCD,it is easy to be misdiagnosed or missed and it is potentially fatal without timely treatment. This disease can be detected early through the newborn screening. Maternal carnitine deficiency and the secondary carnitine deficiency caused by other diseases should be excluded. Genetic test can give a clear diagnosis. Avoiding hunger and use of oral L-carnitine supplementation to maintain normal plasma carnitine concentrations are effective treatments.
ABSTRACT
()of recessive hereditary diseases caused by the dysfunction of enzymes required for fatty acids to enter mitochondria or fatty acid beta-oxidation,including carnitine transport disorders and fatty acid beta-oxidation disorders. Clinical symptoms are non-specific,involving multiple organs,such as liver,myocardium,skeletal muscle,brain and kidney. Most FAOD patients diagnosed by newborn screening have no clinical symptoms or mild symptoms through early intervention management,but they are prone to acute onset or even sudden death under stress conditions such as hunger and exercise. Long-term follow-up and management can effectively reduce the mortality and morbidity rate of FAOD.
ABSTRACT
Fatty acid oxidation disorders(FAOD)include more than 10 kinds of diseases,they all belong to autosomal recessive diseases and are common inherited metabolic diseases. Onset age of the patients with FAOD are from newborn to adult. The clinical manifestations were nonspecific,mainly manifested as liver disease,cardiomyopathy and muscle diseases. Detection of free carnitine and acylcarnitines in blood by tandem mass spectrometry and detection of gene mutations are important methods for diagnosis of such diseases. Tandem mass screening for neonatal screening is helpful for early diagnosis and early treatment of FAOD. Primary carnitine deficiency and multiple acyl-CoA dehydrogenase deficiency can be treated by specific therapeutic drugs with good effect. There are no specific drugs for other diseases,which need symptomatic treatment.