Perinatal Reduced Blood Concentrations of Free Carnitine and Acylcarnitines in Infants with Cystic Fibrosis.

OBJECTIVE: Cystic fibrosis (CF) is a multisystemic inherited disease. The aim of this study was to determine free carnitine (FC) and acylcarnitine concentrations in CF newborns with various mutations of the CFTR gene perinatally. STUDY DESIGN: FC/acylcarnitines were determined in dried blood spots via liquid chromatography-tandem mass spectrometry (LC-MS/MS) on the third day of life of full-term normal (n = 50) and CF (n = 28) newborns. For infants with elevated immunoreactive trypsinogen values, FC/acylcarnitines were quantified again 48 hours later, followed by mutational analysis of CFTR gene via Sanger sequencing. RESULTS: Initial FC and sums of acylcarnitine concentrations were statistically significantly lower in CF patients than in controls and even lower 48 hours later. The mutations F508del and 621 + 1G > T were predominantly identified among CF patients. CONCLUSION: Low FC and acylcarnitine concentrations were measured perinatally in CF patients, for all CFTR mutations detected. Carnitine supplementation of breastfeeding mothers could be beneficial.

Clinical evaluation and mutational analysis of GALK and GALE genes in patients with galactosemia in Greece: one novel mutation and two rare cases.

BACKGROUND: Deficiencies of galactokinase (GALK) and UDP-epimerase (GALE) are implicated with galactose metabolic disorders. The aim of the study was the identification of mutations in GALK and GALE genes and clinical evaluation of patients. METHODS: Five patients with GALK and five with GALE deficiency were picked up via the Neonatal Screening Program. Additionally, two females, 4 years old, were referred with late diagnosed galactosemia, as rare cases. Mutational analysis was conducted via Sanger sequencing, while in silico analysis tools were utilized for the novel mutation. Psychomotor and speech development tests were performed, as well. RESULTS: The mutation p.Pro28Thr was identified in both alleles in GALK-deficient patients of Roma (gypsy) origin, whereas the novel p.Asn39Ser was detected in two non-Roma patients. In GALE-deficient patients benign and/or likely benign mutations were found. Psychomotor and speech delay were determined in the Roma GALK patients. In each of the late diagnosed females, four mutations were identified in all galactosemia-related genes. CONCLUSIONS: The mutational spectrums of GALE- and GALK-deficient patients in Greece are presented for the first time along with a clinical evaluation. Mutational analysis in all galactosemia-related genes of symptomatic patients is highly recommended for future cases.

Mutational analysis of GALT gene in Greek patients with galactosaemia: identification of two novel mutations and clinical evaluation.

Classical galactosaemia is an inborn error of metabolism due to the deficiency of the enzyme galactose-1-phosphate uridylyltransferase (GALT). The aim of the study was to identify the underlying mutations in Greek patients with GALT deficiency and evaluate their psychomotor and speech development. Patients with GALT deficiency (n = 17) were picked up through neonatal screening. Mutational analysis was conducted via Sanger sequencing, while in silico analysis was used in the cases of novel missense mutations. Psychomotor speech development tests were utilized for the clinical evaluation of the patients. Eleven different mutations in the GALT gene were detected in the patient cohort, including two novel ones. The most frequent mutation was p.Q188R (c.563 A > G). As for the novel mutations, p.M298I (c.894 G > A) was identified in four out of 32 independent alleles, while p.P115S (c.343 C > T) was identified once. Psychomotor evaluation revealed that most of the patients were found in the borderline area (Peabody test), while only two had speech delay problems. The WISK test revealed three patients at borderline limits and two were at lower than normal limits. The mutational spectrum of the GALT gene in Greek patients is presented for the first time. The mutation p.Q188R is the most frequent among Greek patients. Two novel mutations were identified and their potential pathogenicity was estimated. Regarding the phenotypic characteristics, psychomotor disturbances and speech delay were mainly observed among GALT-deficient patients.

Study of the effect of CYP2C19 polymorphisms on omeprazole pharmacokinetics by utilizing validated LC-MS/MS and Real Time-PCR methods.

A fully automated liquid chromatography-tandem mass spectrometry (LC-MS/MS) method was developed for the determination of omeprazole in human plasma. Utilization of 96-well plates and robotic liquid handling workstations, rendered the whole procedure very fast, compared to the manual respective procedure of Liquid-Liquid Extraction (LLE). Sample analysis was performed by reversed phase LC-MS/MS, with positive electrospray ionization, using multiple reaction monitoring (MRM). The method required low plasma volumes and analysis of samples was completed in short run times. It was fully validated and applied to a pharmacokinetic study after per os administration of 20mg tablet formulations of omeprazole. The obtained concentrations were used for the calculation of the basic omeprazole pharmacokinetic parameters. Some variations observed in pharmacokinetic parameters among subjects were attributed to differences of CYP2C19 genotype. Therefore, a novel molecular method was developed in which DNA analysis was conducted by using Real Time-Polymerase Chain Reaction (Real Time-PCR). As source of biological material, Dried Blood Spots (DBS) were utilized, offering an alternative and advantageous strategy for such kind of studies.

Hawkinsinuria in two unrelated Greek newborns: identification of a novel variant, biochemical findings and treatment.

BACKGROUND: Hawkinsinuria is a rare inborn error of tyrosine metabolism. OBJECTIVES: To study novel hawkinsinuria cases by monitoring their biochemical profile and conducting a mutation analysis. SUBJECTS AND METHODS: Among 92,519 newborns that underwent expanded newborn screening, two unrelated cases with high tyrosine blood levels were further investigated by chromatographic techniques and via genetic testing for 4-hydroxyphenylpyruvate dioxygenase (HPD) gene. RESULTS: Elevated levels were monitored for blood/plasma tyrosine and for the specific diagnostic markers in urine. The two newborns were put on a special low tyrosine diet. Till completion of the 1st year of their life, liver function tests and brain MRI were normal. The mutation A33T was identified in both cases, while one neonate carried an additional novel mutation of HPD gene (V212M). CONCLUSIONS: Two mutations of HPD gene, A33T, which are associated with hawkinsinuria and a novel one (V212M) were detected for the 1st time in Greek newborns.

Clinical diagnostic Next-Generation sequencing: the case of CFTR carrier screening.

A 23-mutation panel for CFTR carrier screening is recommended to women of reproductive age by the American College of Obstetricians and Gynecologists. In the present study the optimized efficiency regarding the carrier rate of Next-Generation sequencing (NGS) technology is compared to the one of limited mutation detection panels. A total of 824 consequent cases were subjected to the commercial Cystic Fibrosis Genotyping Assay. Some 188 negative samples randomly selected from the initial group of probands were further subjected to an extended mutation panel characterized by 92% detection rate, as well as to massive parallel sequencing. Twenty-two probands subjected to the commercial assay proved to carry one mutation included in the ACOG panel (carrier rate 0.0267). The latter panels revealed the presence of mutations not included in the ACOG panel in four probands, resulting to an increase of carrier rate of 0.0106 in the case of in-house panel and an increase of rate of 0.0213 if NGS was used. The above data seem to support the implementation of NGS in the routine CFTR carrier screening.

Early screening of FTO and MC4R variants in newborns of Greek origin.

BACKGROUND: Variants of fat mass and obesity associated gene (FTO) and melanocortin-4 receptor gene (MC4R) are related to obesity, overweight and type 2 diabetes. OBJECTIVES: To examine the presence of FTO and MC4R variants in Greek newborns. SUBJECTS AND METHODS: A total 1530 newborns of Greek origin were subjected to genetic testing for rs9939609 (FTO) and for rs17782313 (MC4R) variants using dried blood spot (DBS) analysis. RESULTS: Some 20.2% of newborns carried none of the tested variants. FTO homozygotes and FTO heterozygotes correspond to 18.0% and 45.9% of neonates, respectively. MC4R homozygotes and MC4R heterozygotes were identified in 6.7% and 36.3% of neonates, respectively. Of the infants, 2.2% carried both variants in homozygosity, whereas heterozygotes for both variants correspond to 16.7% of the tested neonates. CONCLUSION: The results indicate high prevalence of homozygosity and heterozygosity for tested variants. Early screening via DBS may be beneficial in order to adopt a healthy lifestyle.

Glucose-6-Phosphate Dehydrogenase (G6PD) deficiency in Greek newborns: the Mediterranean C563T mutation screening.

Glucose-6-Phosphate Dehydrogenase (G6PD) gene is located at the X-chromosome at Xq28 and the disease is recessively inherited predominantly in males. More than 400 variants have been proposed based on clinical and enzymatic studies. The aim of the current study was to identify C563T mutation in G6PD-deficient newborns and to correlate the enzyme residual activity with the presence of the mutation. Some 1189 full-term neonates aged 3-5 days old were tested for G6PD activity in dried blood spots from Guthrie cards using a commercial kit. DNA extraction from Guthrie cards and mutation identification among the deficient samples were performed with current techniques. A total of 92 (7.7%) newborns were G6PD-deficient. In 46 (50%), the mutation C563T was identified. The residual activity in C563T hemizygote males (n = 28) was statistically significantly lower (1.23 ± 0.93 U/g Hb) than that in non-C563T G6PD-deficient males (n = 25) (4.01 ± 1.20 U/g Hb, p < 0.0001) and in controls (13.6 ± 2.9 U/g Hb, p < 0.0001). In C563T heterozygote females, the estimated enzyme activity was lower than that determined in non-C563T females. Male C563T hemizygotes suffer from G6PD deficiency and severe neonatal jaundice. G6PD activity showed statistically significant correlation with total bilirubin blood levels.

High incidence of partial biotinidase deficiency cases in newborns of Greek origin.

Biotinidase deficiency (BTD) is an inherited disorder with severe clinical manifestations if not treated early. 63,119 neonates were tested for BTD according to a 3-step protocol. Biotinidase activity was initially estimated through standard colorimetric method on dried blood spots, then the suspected samples were subjected to molecular analysis of the BT gene and determination of BT activity in serum through an HPLC method. 14 infants with partial BTD (incidence 1:4508) were detected. Nine of them were homozygotes (D444H/D444H), and 4 compound heterozygotes carrying D444H combined with Q456H, T532M, C186Y and R157H, respectively. All were asymptomatic and supplemented with 10mg biotin. Although the number of screened neonates is rather small, it may be suggested that the incidence of the partial BTD infants is the highest ever reported. Detection of BTD should be added to the Greek national neonatal screening program.

Characterization of the molecular spectrum of Medium-Chain Acyl-CoA Dehydrogenase Deficiency in a Greek newborns cohort: identification of a novel variant.

OBJECTIVES: The purpose of the current study was to screen newborns in Greece and to identify the responsible mutations for Medium-Chain Acyl-CoA Dehydrogenase Deficiency (MCADD). DESIGN AND METHODS: 47.812 neonates were screened for the potential presence of MCADD in Greece, via a LC-MS/MS protocol. The "suspected" samples were subjected to genetic testing via PCR-RFLP and sequencing of the coding region of the ACADM gene. Urine samples were collected and then analyzed with a GC/MS method. RESULTS: The MCADD prevalence is 1 in 15,937 births. The alleles c.985A>G and c.245insT were detected in the 29.2% and 20.8% of the "suspected" cohort, respectively. A novel variant with potential pathogenicity was identified. CONCLUSIONS: The c.245insT allele seems to prevail in the Greek cohort of "suspected" specimens. Therefore, this variant along with the c.985A>G allele could constitute a panel for both prenatal and neonatal MCADD screening in the Greek population.

Mutational analysis for biotinidase deficiency of a Greek patients' cohort ascertained through expanded newborn screening.

Late-onset multiple carboxylase deficiency, also known as biotinidase (BTD) deficiency, is an autosomal recessively inherited disorder of biotin metabolism. Its early diagnosis and treatment seems that it can even fully prevent its various clinical manifestations. Mutations in the BTD gene scattered throughout its coding region have been detected in patients ascertained either through newborn screening or clinically. From March 2010 up to June 2011, 18 954 Greek neonates were subjected to biochemical determination of BTD activity through a semiquantitative fluoroimmunoassay. Subsequently, the first cohort of our 'suspected' samples was further tested for the presence of aberrations associated either with partial or profound BTD deficiency through sequencing of the coding region of the BTD gene, including splice-site junctions. On the basis of the molecular data derived from the study of our first cohort of 'suspected' samples, a panel of four mutations, most frequently encountered in the Greek population, was created, and a rapid, reliable and cost-effective real-time-based genotyping assay for the detection of these mutations was developed. This is the first report about the BTD mutational spectrum in Greece, and it could be a beneficial utility in the differential clinical diagnosis of BTD deficiency.

Expanded newborn screening in Greece: 30 months of experience.

In Greece, the National Newborn Screening Program was initiated in 1974 and is performed by the Institute of Child Health (ICH). However, there is a complete absence of conditions that have high rates of mortality and a relatively high prevalence listed in the Catalogue of Disorders screened by the ICH. Our laboratory has expanded the existing NBS program to include newborn screening for inborn errors of metabolism, screening for cystic fibrosis (the most common congenital disorder in the Greek population), congenital adrenal hyperplasia, and for biotinidase deficiency. From July 2007 to December 2009, 45,000 dried blood spots (DBS) were collected from infants born in Athens, Greece, and were analyzed. We present a report of our 30-month experience in the newborn screening area. The samples were tested for amino acidopathies, fatty acid oxidation disorders (FAOD), and organic acid metabolic disorders by applying flow injection analysis-electrospray ionization-tandem mass spectrometry (FIA-ESI-MS/MS); for cystic fibrosis by immunoreactive trypsinogen (IRT) measurement (time-resolved fluoroimmunoassay); for congenital adrenal hyperplasia by fluoroimmunoassay to measure the 17 hydroxy-progesterone level; and for biotinidase deficiency using a colorimetric method and a semiquantitative fluoroimmunoassay to determine biotinidase activity. Sample analysis resulted in establishing cutoff values for the respective disease markers for the first time in the Greek population. Four infants were identified with cystic fibrosis, two with congenital adrenal hyperplasia, two with phenylketonuria (PKU), one with medium-chain acyl CoA dehydrogenase deficiency (MCADD), and one with biotinidase deficiency. To the best of our knowledge, this is the first article reporting the status of expanded newborn screening in Greece.