An unusually high frequency of SCAD deficiency caused by two pathogenic variants in the ACADS gene and its relationship to the ethnic structure in Slovakia.

BACKGROUND: Short-chain acyl-CoA dehydrogenase deficiency (SCADD) represents a rare autosomal recessive inborn metabolic disorder of mitochondrial ß-oxidation of monocarboxylic acids. Clinical symptoms can vary from a severe life-threatening condition to an asymptomatic state, reported in the majority of cases. Since the expansion of newborn screenings, more than three hundred probands were admitted for molecular-genetic analysis, most selected because of elevated values of C4-acylcarnitine detected in newborn screenings in Slovakia. Searching for the principal genomic changes led us to the selection of sixty-two patients in whom the presence of sequence variants in the ACADS gene was analysed and correlated with the available biochemical and clinical data. METHODS: Biochemical and molecular genetic tests were performed. Acylcarnitine profiles focused on an elevated level of C4-acylcarnitine, which was analysed via tandem mass spectrometry. Urinary organic acids, specifically a quantity of ethylmalonic acid, were determined by gas chromatography/mass spectrometry. The entire coding region of the ACADS gene was sequenced. A low-cost restriction fragment length polymorphism of PCR amplified fragments analysis (PCR-RFLP) of pathogenic variants was introduced and implemented for the molecular-genetic algorithm appropriate for the Slovak population. RESULTS: Our molecular genetic study was performed on sixty-two patients with a pathological biochemical pattern related to short-chain acyl-CoA dehydrogenase deficiency. In this cohort, we discovered a high occurrence of two rare pathogenic variants-the deletion c.310_312delGAG and the substitution c.1138C>T, with allelic frequencies of 64% and 31%, respectively. Up to 86% of investigated individuals belong to the Roma ethnic group. CONCLUSIONS: Analogous to other countries, SCADD is not included in the newborn screening programme. Based on the exceeded levels of the specific biomarker C4-acylcarnitine as well as ethylmalonic acid, we revealed a high prevalence of short-chain acyl-CoA dehydrogenase deficiency cases, confirmed by the findings of two rare pathogenic variants. A deletion c.310_312delGAG and c.1138C > T substitution in the ACADS gene appear with a high frequency in the Roma ethnic group of Slovakia. Due to the uncertainty of the pathogenicity and clinical consequences, it is important to follow up the morbidity and mortality in these patients over time and evaluate SCADD in relation to clinical outcomes and preventive healthcare recommendations.

Simultaneous analysis of carbohydrates, polyols and amines in urine samples using chemical ionization gas chromatography with tandem mass spectrometry.

A simple method for the simultaneous derivatization of carbohydrates, polyols, amines and amino acids using hexamethyldisilazane and N,O-bis(trimethylsilyl)trifluoroacetamide was developed. This method allows the direct derivatization of urine samples without sample pretreatment before derivatization. The method was successfully used for analysis of the selected metabolites in urine samples of healthy individuals and neonates suffering from galactosemia. The limits of detection by positive chemical ionization gas chromatography with tandem mass spectrometry analysis were in the range of 1.0 mgL-1 for mannitol to 4.7 mg/L for glucose.

Augmenting clinical interpretability of thiopurine methyltransferase laboratory evaluation.

OBJECTIVE: Individuals with decreased thiopurine methyltransferase (TPMT) activity are at risk of adverse effects of thiopurine administration whereas its increased activity may inactivate drugs faster. We evaluated genotype-phenotype correlations in patients with suspected hematological malignancies and inflammatory bowel disease from our region based on findings of nonlinear TPMT enzyme kinetics previously unreported. PATIENTS AND METHODS: The study group comprised 267 individuals. They were screened for the most common variants of low TPMT activity. TPMT activity was measured in erythrocytes using the HPLC rate-blanked method. RESULTS: Thirty-three patients (12.4%) were heterozygous (26 were TPMT*1/*3A, 5 TPMT*1/*2, 2 TPMT *1/*3C) and 1 was a compound heterozygote (*2/*3A). Normal and low normal TPMT activities substantially overlapped in wild-type and heterozygous individuals, whereas high activities were found in 29 wild-type genotyped patients. Extreme and life-threatening toxicity was observed in the compound heterozygote patient. CONCLUSION: Activity measurement performed at diagnosis provides clinicians with information on immediate pharmacokinetic-related adverse events and/or hypermetabolism, and genotyping may indicate the rate of pharmacodynamic thioguanine nucleotide accumulation due to slower overall thiopurine metabolism.

[Historical aspects of the Smith-Lemli-Opitz syndrome]. / Historické aspekty Smithovho-Lemliho-Opitzovho syndrómu.

The new malformation syndrome was first described approximately 50 years ago in three unrelated patients in Department of Pediatrics at the University of Wisconsin, Madison, (Smith, Lemli, Opitz 1964). This syndrome was called RSH syndrome after the first 3 patients studied. First Slovak patient with phenotypic features of this new syndrome was described by professor Srsen in 1972. In 1994 Tint from VA Medical Center, E. Orange, New Jersey analyzed plasma sterols of patient with Smith-Lemli-Opitz syndrome and found out that in addition to low plasma cholesterol level, the patient had 1000-fold increase of the plasma level of 7-dehydrocholesterol, the immediate precursor of cholesterol biosynthesis. After this biochemical discovery Smith-Lemli-Opitz syndrome became the metabolic-malformation syndrome with an exactly defined impairment of cholesterol metabolism. The first patient with biochemically proved Smith-Lemli-Opitz syndrome in Slovakia was described by Behulova et al. (1997) in cooperation with Department of Biochemistry and Medical Biotechnology, Federico II University in Naples, Italy. The three years later a screening method UV spectrometry of serum lipids for detection of 7-dehydrocholesterol was established in Department of Biochemistry, University Children´s Hospital in cooperation with the Institute of preventive and clinical medicine in Bratislava (Skodova et al.,2000). First results of molecular analysis of the 7-dehydrocholesterol reductase gene in 10 unrelated Czech and Slovak patients with Smith-Lemli-Opitz syndrome were reported by Kozak et al. (2000). The same year the first prenatal diagnosis of Smith-Lemli-Opitz syndrome by mutation analysis was achieved (Bzduch et al., 2000). Our research activities on this topic drew good response from abroad.

Preanalytical quality improvement: in quality we trust.

Total quality in laboratory medicine should be defined as the guarantee that each activity throughout the total testing process is correctly performed, providing valuable medical decision-making and effective patient care. In the past decades, a 10-fold reduction in the analytical error rate has been achieved thanks to improvements in both reliability and standardization of analytical techniques, reagents, and instrumentation. Notable advances in information technology, quality control and quality assurance methods have also assured a valuable contribution for reducing diagnostic errors. Nevertheless, several lines of evidence still suggest that most errors in laboratory diagnostics fall outside the analytical phase, and the pre- and postanalytical steps have been found to be much more vulnerable. This collective paper, which is the logical continuum of the former already published in this journal 2 years ago, provides additional contribution to risk management in the preanalytical phase and is a synopsis of the lectures of the 2nd European Federation of Clinical Chemistry and Laboratory Medicine (EFLM)-Becton Dickinson (BD) European Conference on Preanalytical Phase meeting entitled "Preanalytical quality improvement: in quality we trust" (Zagreb, Croatia, 1-2 March 2013). The leading topics that will be discussed include quality indicators for preanalytical phase, phlebotomy practices for collection of blood gas analysis and pediatric samples, lipemia and blood collection tube interferences, preanalytical requirements of urinalysis, molecular biology hemostasis and platelet testing, as well as indications on best practices for safe blood collection. Auditing of the preanalytical phase by ISO assessors and external quality assessment for preanalytical phase are also discussed.

Targeted metabolomic analysis of plasma samples for the diagnosis of inherited metabolic disorders.

Metabolomics has become an important tool in clinical research and diagnosis of human diseases. In this work we focused on the diagnosis of inherited metabolic disorders (IMDs) in plasma samples using a targeted metabolomic approach. The plasma samples were analyzed with the flow injection analysis method. All the experiments were performed on a QTRAP 5500 tandem mass spectrometer (AB SCIEX, U.S.A.) with electrospray ionization. The compounds were measured in a multiple reaction monitoring mode. We analyzed 50 control samples and 34 samples with defects in amino acid metabolism (phenylketonuria, maple syrup urine disease, tyrosinemia I, argininemia, homocystinuria, carbamoyl phosphate synthetase deficiency, ornithine transcarbamylase deficiency, nonketotic hyperglycinemia), organic acidurias (methylmalonic aciduria, propionic aciduria, glutaric aciduria I, 3-hydroxy-3-methylglutaric aciduria, isovaleric aciduria), and mitochondrial defects (medium-chain acyl-coenzyme A dehydrogenase deficiency, carnitine palmitoyltransferase II deficiency). The controls were distinguished from the patient samples by principal component analysis and hierarchical clustering. Approximately 80% of patients were clearly detected by absolute metabolite concentrations, the sum of variance for first two principle components was in the range of 44-55%. Other patient samples were assigned due to the characteristic ratio of metabolites (the sum of variance for first two principle components 77 and 83%). This study has revealed that targeted metabolomic tools with automated and unsupervised processing can be applied for the diagnosis of various IMDs.

Determination of sevoflurane and its metabolite hexafluoroisopropanol by direct injection of human plasma into gas chromatography-tandem mass spectrometry.

The developed method for trace analysis of volatile components in plasma allows direct injection of up to 150 samples to the GC-MS/MS system without injector cleaning. This method requires no modification of plasma and the working environment does not interfere with the determination of these analytes. The method allows simultaneous quantification of non-polar sevoflurane and its polar metabolite hexafluoroisopropanol (free, unconjugated form). It is characterized by high repeatability and sensitivity with the detection limit of 0.009 mg L(-1) for sevoflurane and 0.018 mg L(-1) for hexafluoroisopropanol and the linear range 0.050-150 mg L(-1). The method was used to determine the concentration of sevoflurane and hexafluoroisopropanol in plasma samples of 7 patients undergoing general anesthesia with sevoflurane. The average concentration of sevoflurane and free hexafluoroisopropanol was 57.2 mg L(-1) and 0.39 mg L(-1), respectively. The method can be applied for clinical monitoring, as well as for analytical toxicology.

Newborn with neonatal form of molybdenum cofactor deficiency - the first patient in the Slovak Republic.

OBJECTIVE: To present the case of a term newborn with rapid progression of signs of neurodegenerative disease. RESULTS: In a case of a term newborn with numerous dysmorphic features, with seizure activity from the 3rd day of life, hypertonia and serious changes on brain parenchyma were presented. Diagnosis of molybdenum cofactor deficiency was confirmed by the decreased level of uric acid, 31 µmol/l, in serum, increased excretion of thiosulfate and S-sulfocysteine in urine, taurine (1729.3 µmol/mmol crea; normal range 30-300 µmol/mmol crea) and xanthine (276.9 µmol/mmol crea; normal range < 25 µmol/mmol crea) in urine. Sulfite oxidase activity on skin fibroblasts in culture was not detectable. The patient died at the age of 28 days of life. CONCLUSION: Deficiency of molybdenum cofactor leads to accumulation of toxic metabolites (levels of sulfite), which causes disturbances of neurotransmitters even before delivery. Therapy is symptomatic, no effective therapy is available. Seizures are difficult to suppress. This case report is about the first patient in Slovakia.

Conjugated hyperbilirubinaemia as the first manifestation of mevalonic aciduria in a term newborn.

OBJECTIVES: To present clinical and laboratory findings in the case of a term newborn with conjugated hyperbilirubinaemia and to stress the importance of differential diagnosis. RESULTS: A term newborn delivered by caesarean section (birth weight 2550 g, birth length 47 cm, value of Apgar score 9/10) with good direct adaptation had on the first day of life increased levels of conjugated bilirubin (23 micromol/l), unconjugated bilirubin (55 micromol/l) and C-reactive protein 39.4 g/l. The diagnosis of mevalonic aciduria was confirmed by urine analysis (mevalonolactone 393 micromol/mmol crea, normal range <2.0 micromol/mmol crea; mevalonic acid 40.5 micromol/mmol crea, normal range <0.04 micromol/mmol crea). CONCLUSION: Mevalonic aciduria can be clinically distinguished based on symptoms of neurological involvement. It can also present itself with hepatosplenomegaly, lymphadenopathy, anaemia, leukocytosis, increased sedimentation rates and levels of C-reactive protein. In cases of conjugated hyperbilirubinaemia of unknown aetiology it is important to exclude mevalonic aciduria by urine investigation for organic acids.

Reversible asphyxial status in a newborn due to neonatal form of carnitine palmitoyltransferase II deficiency.

OBJECTIVES: To present a term newborn with severe asphyxial status due to dysrrhythmia induced by the neonatal form of carnitine palmitoyltransferase II deficiency (CPT II). RESULTS: Term newborn delivered spontaneously (birth weight 3450 grams, birth length 52 cm, values of Apgar score 10/10) with good direct adaptation, on second day of life he manifested severe asphyxial status followed by cardiorespiratory insufficiency with circulatory failure. After prolonged resuscitation of 3 hours, the child was admitted to our neonatological department. Diagnosis of CPT II was confirmed (free carnitine level in blood 12.2 micromol/l; ratio (C16+C18):1/C2 was 0.760 by tandem mass spectrometry; activity of CPT II in leukocytes was 0.082 micromol/min x gram protein). After appropriate treatment the patient survived the critical period. CONCLUSIONS: Neonatal form of CPT II deficiency is the most severe form and is considered to be invariably fatal. This kind of metabolic disease is congenital, but cardiac problems are not detectable during the prenatal period. Fasting in the early newborn period is a main trigger of CPT II deficiency signs. The authors emphasise the relevance of investigating acylcarnitine profiles and carnitine in serum in all cases of severe postnatal asphyxia and in cases of unusual newborn arrhythmias since some forms of disturbances in beta oxidation of fatty acids are partially treatable.