No abstract available.
Blood Platelets* ; Carnitine* ; Humans* ; Platelet Activating Factor* ; Spermatozoa*

OBJECTIVE: To report on the clinical, metabolic and genetic characteristics of a child with carnitine palmitoyl transferase 1A (CPT1A) deficiency. METHODS: Clinical data and the level of acylcarnitine for a child who initially presented as epilepsy were analyzed. Genomic DNA was extracted from peripheral blood samples of the child and her parents and subjected to next-generation sequencing (NGS). RESULTS: Mass spectrometry of blood acylcarnitine indicated increased carnitine 0 (C0) and significantly increased C0/ (C16+C18). DNA sequencing revealed that the child has carried compound heterozygous variants of the CPT1A gene, namely c.1846G>A and c.2201T>C, which were respectively inherited from her mother and father. CONCLUSION CPT1A presenting initially as epilepsy was unreported previously. Analysis of blood acylcarnitine C0 and C0/ (C16 + C18) ratio and NGS are necessary for the identification and diagnosis of CPT1A deficiency. The c.1846G>A and c.2201T>C variants of the CPT1A gene probably underlay the disease in this child. Above finding has also enriched the spectrum of CPT1A gene variants.
Carnitine/blood* ; Carnitine O-Palmitoyltransferase/genetics* ; Child ; DNA Mutational Analysis ; Female ; Humans ; Hypoglycemia/genetics* ; Lipid Metabolism, Inborn Errors/genetics*

OBJECTIVETo determine the levels of carnitine in plasma and daily excretion of carnitine in urine of healthy adults so as to provide the reference standard for studying the changes of carnitine in patients.

METHODSCarnitine in plasma and urine was assayed with high performance liquid chromatography (HPLC). The levels of total carnitine (TC), free carnitine (FC) and acetyl-carnitine (AC) in fasting plasma and the daily excretion of TC, FC and AC in urine were assayed in 40 healthy adults (20 men and 20 women) with standard diet.

RESULTSGood linearity (r 2 > or = 0.999) was observed in assaying TC, FC and AC. The relative standard deviation (RSD) was lower than 9.1% and bias lower than 5.6%. It was showed that the plasmatic levels of TC, FC and AC in healthy men [(53.1 +/- 8.5), (41.2 +/- 6.1), (6.2 +/- 0.6) mumol/L] were significantly higher than those in healthy women [(45.4 +/- 5.6), (35.2 +/- 4.9), (5.7 +/- 0.7) mumol/L] (P = 0.002, 0.002, 0.035). The daily urinary excretion of TC, FC and AC in healthy men [(386.1 +/- 22.9), (180.5 +/- 31.8), (33.8 +/- 3.3) mumol] were also significantly higher than those in healthy women [(240.1 +/- 35.6), (112.7 +/- 22.6), (29.3 +/- 4.3) mumol] (P < 0.0005, < 0.0005, < 0.0005) when the adults were given standard diet. Both the plasmatic levels and the daily urinary excretion of TC, FC and AC were of significantly positive correlation with lean body mass (LBM) (r = 0.501-0.856). The (TC-FC)/FC ratios in plasma were 0.29 +/- 0.05 for male and 0.29 +/- 0.04 for female.

CONCLUSIONGood precision and accuracy were observed in assaying carnitine with HPLC. After standard diet, both the level of carnitine in fasting plasma and the daily urinary carnitine excretion of healthy adults were positively correlated with LBM.

Acetylcarnitine ; blood ; urine ; Adult ; Carnitine ; blood ; urine ; Chromatography, High Pressure Liquid ; Female ; Humans ; Male ; Reference Values ; Sex Factors

OBJECTIVETo determine the levels of blood spot carnitine and acylcarnitine in children aged 0-15 years by tandem mass spectrometry, offer basic data for evaluating carnitine nutritional status and diagnosing metabolic diseases of organic acid and fatty acid.

METHODSThe concentration of carnitine and acylcarnitines were measured in blood spot by tandem mass spectrometry using underivatized samples. The samples included those from 1376 perinatal neonates, 49 neonates above 1 week of life, 64 children aged up to 1 year and 401 children aged 1 year to 15 years. A few premature infants and low birth weight infants were involved in perinatal neonates without selection. Other samples were taken from mainly outdoor patients for little surgical preoperative examination. Patients suffering from fever, diarrhea, liver disease, severe fat-metabolic diseases were excluded from this study.

RESULTSThe concentrations of carnitine (C(0)); short-chain acylcarnitines (SC-AC), including acetyl (C(2)), propionyl (C(3)), malonyl (C(3)DC), butyryl (C(4)), methylmalonyl (C(4)DC), isovaleryl (C(5)), glutaryl (C(5)DC); middle-chain acylcarnitines (MC-AC), including hexanoyl (C(6)), hexanediol (C(6)DC), octylenoyl (C(8:1)), octanoyl (C(8)), decadienoyl (C(10:2)), decanoyl (C(10:1)), decanoyl (C(10)); total carnitine and acylcarnitines (TCAC)were lower in neonate, highest in 1-3 months of age, higher in 6-12 months of age, and kept at the same level between 2 and 15 years of age. The concentrations of total long-chain acylcarnitines (LC-AC), including lauren (C(12:1)), lauroyl (C(12)), tetradecanoyl (C(14:1)), tetradecanoyl (C(14)), 3-hydroxy-tetradecanoyl (C(14)OH), hexadecenoyl (C(16:1)), hexadecanoyl (C(16)), 3-hydroxy-hexadecanoyl (C(16)OH), 3-hydroxy-hexadecanoyl (C(16:1)OH), octadecadienoyl (C(18:2)), octadecenoyl (C(18:1)), octadecanoyl (C(18)), 3-hydroxy-octadecenoyl (C(18:1)OH), and 3-hydroxy-octadecanoyl (C(18)OH) were the highest in neonate, decreased gradually, and kept the same level between 2 and 15 years of age. The concentrations of C(0) (23.387 ± 7.702) µmol/L, (30.064 ± 8.252) µmol/L, (25.021 ± 6.630) µmol/L, of LC-AC (4.998 ± 1.557) µmol/L, (2.854 ± 0.821) µmol/L, (2.459 ± 0.553) µmol/L, of TCAC (43.497 ± 12.632) µmol/L, (49.013 ± 12.497) µmol/L, (39.656 ± 9.257) µmol/L were significantly different among the groups of neonate, up to 1 year and above 1 year (P < 0.01). The concentrations of C(0) (24.115 ± 7.715) µmol/L and TCAC (43.65 ± 5.252) µmol/L in perinatal male neonates were higher than that (22.696 ± 7.246) µmol/L, TCAC (41.90 ± 5.038) µmol/L in female neonates. The C(0)/TCAC ratio of neonatal group (54.0% ± 7.1%) was significantly lower than that in the children group (62.1% ± 6.1%, P < 0.05), LC-AC/TCAC (33.5% ± 6.0%), MC-AC/TCAC (1.3% ± 0.3%), SC-AC/TCAC (11.6% ± 2.5%)ratios of neonatal group were higher than that of children group respectively (30.1% ± 4.9%; 0.9% ± 0.6%; 6.5% ± 2.3%, P < 0.05).

CONCLUSIONSConcentrations and profiles of carnitine and acylcarnitines change significantly during the first year of life, the age should be considered as a factor when evaluating carnitine nutritional status and diagnosing metabolic diseases of organic acid and fatty acid. Concentrations of carnitine and acylcarnitines were a little higher in male neonates than in female.

Adolescent ; Carnitine ; analogs & derivatives ; blood ; Child ; Child, Preschool ; Female ; Humans ; Infant ; Infant, Newborn ; Male ; Tandem Mass Spectrometry ; methods

OBJECTIVETo investigate the fat emulsion tolerance in preterm infants of different gestational ages in the early stage after birth.

METHODSA total of 98 preterm infants were enrolled and divided into extremely preterm infant group (n=17), early preterm infant group (n=48), and moderate-to-late preterm infant group (n=33). According to the dose of fat emulsion, they were further divided into low- and high-dose subgroups. The umbilical cord blood and dried blood filter papers within 3 days after birth were collected. Tandem mass spectrometry was used to measure the content of short-, medium-, and long-chain acylcarnitines.

RESULTSThe extremely preterm infant and early preterm infant groups had a significantly lower content of long-chain acylcarnitines in the umbilical cord blood and dried blood filter papers within 3 days after birth than the moderate-to-late preterm infant group (P<0.05), and the content was positively correlated with gestational age (P<0.01). On the second day after birth, the low-dose fat emulsion subgroup had a significantly higher content of short-, medium-, and long-chain acylcarnitines than the high-dose fat emulsion subgroup among the extremely preterm infants (P<0.05). In the early preterm infant and moderate-to-late preterm infant groups, there were no significant differences in the content of short-, medium-, and long-chain acylcarnitines between the low- and high-dose fat emulsion subgroups within 3 days after birth.

CONCLUSIONSCompared with moderate-to-late preterm infants, extremely preterm infants and early preterm infants have a lower capacity to metabolize long-chain fatty acids within 3 days after birth. Early preterm infants and moderate-to-late preterm infants may tolerate high-dose fat emulsion in the early stage after birth, but extremely preterm infants may have an insufficient capacity to metabolize high-dose fat emulsion.

Carnitine ; analogs & derivatives ; blood ; Fat Emulsions, Intravenous ; analysis ; metabolism ; Gestational Age ; Humans ; Infant, Newborn ; Infant, Premature ; metabolism

BACKGROUNDData of classical inborn errors of metabolism (IEM) of amino acids, organic acids and fatty acid oxidation are largely lacking in Hong Kong, where mass spectrometry-based expanded newborn screening for IEM has not been initiated. The current study aimed to evaluate the approximate incidence, spectrum and other characteristics of classical IEM in Hong Kong, which would be important in developing an expanded newborn screening program for the local area.

METHODSThe laboratory records of plasma amino acids, plasma acylcarnitines and urine organic acids analyses from year 2005 to 2009 inclusive in three regional chemical pathology laboratories providing biochemical and genetic diagnostic services for IEM were retrospectively reviewed.

RESULTSAmong the cohort, 43 patients were diagnosed of IEM, including 30 cases (69%) of amino acidemias (predominantly citrin deficiency, hyperphenylalaninemia due to 6-pyruvoyl-tetrahydropterin synthase deficiency and tyrosinemia type I), 5 cases (12%) of organic acidemias (predominantly holocarboxylase synthetase deficiency) and 8 cases (19%) of fatty acid oxidation defects (predominantly carnitine-acylcarnitine translocase deficiency). The incidence of classical IEM in Hong Kong was roughly estimated to be at least 1 case per 4122 lives births, or 0.243 cases per 1000 live births. This incidence is similar to those reported worldwide, including the mainland of China. The estimated incidence of hyperphenylalaninemia was 1 in 29 542 live births.

CONCLUSIONSOur data indicate that it is indisputable for the introduction of expanded newborn screening program in Hong Kong. Since Hong Kong is a metropolitan city, a comprehensive expanded newborn screening program and referral system should be available to serve the neonates born in the area.

Acids ; urine ; Amino Acids ; blood ; Carnitine ; analogs & derivatives ; blood ; Hong Kong ; epidemiology ; Humans ; Infant, Newborn ; Metabolism, Inborn Errors ; blood ; diagnosis ; epidemiology ; urine ; Neonatal Screening ; methods ; Tandem Mass Spectrometry

OBJECTIVETo determine serum carnitine levels in patients with liver diseases and to investigate their significance.

METHODS25 patients with acute viral hepatitis, 34 with chronic viral hepatitis, 22 with post hepatitis cirrhosis with normal renal function, 9 with post hepatitis cirrhosis but with renal disfunction, and 40 healthy subjects (serving as controls) were enrolled in this study. An enzymatic cycling method was used to determine the serum free carnitine levels.

RESULTSThe serum free carnitine level was (48.3+/-10.2)micromol/L in the healthy control group. It was (35.2+/-13.2)micromol/L in the acute viral hepatitis group, (36.5+/-9.9)micromol/L in the chronic viral hepatitis group, (45.0+/-11.0)micromol/L in the post hepatitis cirrhosis with normal renal function group, and (83.6+/-50.4)micromol/L in the post hepatitis cirrhosis with renal dysfunction group. Serum free carnitine levels in the acute viral hepatitis and chronic viral hepatitis groups were significantly lower than those in the healthy controls. There were no significant differences in serum free carnitine levels of the post hepatitis cirrhosis group and the normal control group.

CONCLUSIONSPatients with liver diseases can have carnitine metabolism errors. One of the secondary carnitine lack causes is liver disease.

Adolescent ; Adult ; Aged ; Aged, 80 and over ; Carnitine ; blood ; Chronic Disease ; Female ; Hepatitis, Viral, Human ; blood ; Humans ; Liver Cirrhosis ; blood ; Male ; Middle Aged

AIMMalonyl-CoA is regarded as a key signaling molecule in mammalian cells. It is converted to acetyl-CoA, and to a lesser extent, to malonyl acid and malonylcarnitine (C3DC). Availability of carnitine has been reported to be essential for the developing fetus. The objectives of the present study were to analyze associations of malonylcarnitine, acetylcarnitine (C2), and free carnitine (CO) in subjects with orofacial clefts.

METHODOLOGYWe performed a retrospective analysis of carnitine concentration obtained from a newborn screening program carried out in our institution. Concentrations of whole blood malonylcarnitine, acetylcarnitine, and free carnitine were measured using tandem mass spectrometry. The study group consisted of 51 children with nonsyndromic cleft lip with or without cleft palate. In total, 106 healthy children without congenital anomalies served as controls. Cut-off points were established using likelihood ratio values.

RESULTSThe mean concentration of malonylcarnitine in the cleft group was lower than that of the control group, 0.048 micromol x L(-1) vs. 0.058 micromol x L(-1), respectively (P = 0.009). In patients with orofacial cleft, low malonylcarnitine levels (< or = 0.047 micromol x L(-1)) were 1.7 times more predominant than in healthy individuals (P = -0.03). The mean concentration of acetylcarnitine was also lower in affected newborns in comparison to controls, 33.8 micromol x L(-1) vs. 37.8 micromol x L(-1), respectively (P = 0.026). After analysis of acetylcarnitine and free carnitine concentrations, the likelihood ratio test did not indicate valuable cut-offpoints.

CONCLUSIONThe study provides initial data indicating a potential association between decreased malonylcarnitine and abnormal palatogenesis.

Acetylcarnitine ; blood ; Carnitine ; blood ; Chromatography, Liquid ; Cleft Lip ; blood ; Cleft Palate ; blood ; Female ; Humans ; Infant, Newborn ; blood ; Likelihood Functions ; Male ; Malonates ; blood ; Malonyl Coenzyme A ; blood ; Neonatal Screening ; Retrospective Studies ; Tandem Mass Spectrometry

OBJECTIVETo investigate the feasibility of analyzing acylcarnitine in dry filter-paper blood spots by liquid chromatography-tandem mass spectrometry (LC-MS/MS) which could be applied to detect inborn errors of metabolism in neonates.

METHODSWe obtained filter-paper blood from 26 dead infants from a neonatal intensive care unit (NICU) between October 1, 2008 and September 30, 2009. Acylcarnitine and amino acid profiles were obtained with LC-MS/MS. Four infants underwent routine autopsy. The postmortem blood specimens were compared with newborn blood specimens, and with specimens obtained from older infants with metabolic disorders.

RESULTSOf all the 26 patients, 5 (19.2%) were diagnosed as having different kinds of diseases: 3 with methylmalonic acidemia (the concentration of C3, and the ratio of C3/C16, C3/C2 increased), 1 with maple syrup urine disease (the concentration of leucine and isoleucine increased), and 1 with isovaleric acidemia (the concentration of C5 increased).

CONCLUSIONSPostmortem metabolic test can explain infant deaths and provide estimates of deaths attributable to inborn errors of metabolism in NICU. LC-MS/MS is suitable for analysis of postmortem specimens and can be considered for routine application in NICU autopsy.

Amino Acid Metabolism, Inborn Errors ; blood ; diagnosis ; Autopsy ; Carnitine ; blood ; Chromatography, Liquid ; methods ; Female ; Humans ; Infant, Newborn ; Intensive Care Units, Neonatal ; Male ; Tandem Mass Spectrometry ; methods

Medium- and short-chain acyl-CoA dehydrogenase deficiency is a disorder of fatty acid β-oxidation. Gene mutation prevents medium- and short-chain fatty acids from entry into mitochondria for oxidation, which leads to multiple organ dysfunction. In this study, serum acylcarnitines and the organic acid profile in urea were analyzed in two children whose clinical symptoms were hypoglycemia and metabolic acidosis. Moreover, gene mutations in the two children and their parents were evaluated. One of the patients was a 3-day-old male who was admitted to the hospital due to neonatal asphyxia, sucking weakness, and sleepiness. The serum acylcarnitine profile showed increases in medium-chain acylcarnitines (C6-C10), particularly in C8, which showed a concentration of 3.52 μmol/L (reference value: 0.02-0.2 μmol/L). The analysis of organic acids in urea gave a normal result. Sanger sequencing revealed a reported c.580A>G (p.Asn194Asp) homozygous mutation at exon 7 of the ACADM gene. The other patient was a 3-month-old female who was admitted to the hospital due to cough and recurrent fever for around 10 days. The serum acylcarnitine profile showed an increase in serum C4 level, which was 1.66 μmol/L (reference value: 0.06-0.6 μmol/L). The analysis of organic acids in urea showed an increase in the level of ethyl malonic acid, which was 55.9 (reference value: 0-6.2). Sanger sequencing revealed a reported c.625G>A (p.Gly209Ser) homozygous mutation in the ACADS gene. This study indicates that screening tests for genetic metabolic diseases are recommended for children who have unexplained metabolic acidosis and hypoglycemia. Genetic analyses of the ACADM and ACADS genes are helpful for the diagnosis of medium- and short-chain acyl-CoA dehydrogenase deficiency.
Acyl-CoA Dehydrogenase ; deficiency ; genetics ; Carnitine ; analogs & derivatives ; blood ; Female ; Humans ; Infant ; Infant, Newborn ; Lipid Metabolism, Inborn Errors ; genetics ; Male ; Mutation ; Urea ; analysis