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The thirteen new cases of isolated ATP synthase deficiency due to TMEM70 mutation in Slovakia: Clinical and biochemical findings
Abstracts
creatinine. The established method was used to determine creatinine in plasma samples from newborn infants. Results: The deproteinization step was optimized with pure methanol at a plasma:solvent ratio of 1:2. Chromatographic separation was achieved using an octadecyl (C18) reversed-phase column (100 mm × 4.6 mm) using isocratic elution. A mobile phase composed of phosphate buffer (pH 7.1)-methanol in the ratio of 99:1 (v/v) at a flow rate of 1 mL/min was found to be the most suitable for this separation. 10 μL of sample solution or standard solution was injected into the HPLC system and 235 nm was selected as the detection wavelength. Under these chromatographic conditions, creatinine had a retention time of approximately 2.1 min and the total run time was 4 min. The method proved to be linear in the clinical range of creatinine from 2.5 to 20 g/mL. Linear-regression analysis yielded a correlation coefficient of 0.999 and the regression equation was y = 1348,223 × −450,359. The relative standard deviations of within- and betweenassays were b10%. The method was also validated by spiked recoveries with an average recovery from 101.2 to 110.3% for the human plasma samples. No interference from endogenous substances or exogenous substances was observed. Using specimens from neonates, we compared this method with a routinely used automated alkaline picrate method. Conclusion: The proposed HPLC method is simple, rapid, and suitable for the accurate measurement of creatinine in human plasma especially in neonates without analytical interferences, while the Jaffé method may give in these circumstances inaccurate results.
doi:10.1016/j.clinbiochem.2014.04.039
Cod: 013 The thirteen new cases of isolated ATP synthase deficiency due to TMEM70 mutation in Slovakia: Clinical and biochemical findings D. Behulovab, C. Sebovab, S. Tarnokovab, K. Brennerovaa, D. Dolnikovaa, J. Zemand, M. Tesarovad, L. Potocnakovae, J. Chandogac a 1st Dept Ped, Univ Child Hosp, Bratislava, Slovakia b Centre Inher Metab Dis, Dept Lab Med, Univ Child Hosp, Bratislava, Slovakia c Dept Biol Gen and Clin Gen, Univ Hosp, Bratislava, Slovakia d Dept Ped, 1st Fac Med, Charles Univ, Prague, Czech Republic e Univ Child Hosp, Kosice, Slovakia Background: Isolated ATP synthase deficiency may be caused either by mutations in mtDNA or nuclear genes. The TMEM70 gene defect has been recently identified by Czech scientists as a novel nuclear origin of the disease. We report clinical symptoms and essential biochemical findings in patients with TMEM70 mutation detected lately in Slovakia (about 5.5 million inhabitants). Methods: Clinical data and metabolic profiles were evaluated in 13 Slovak patients (7 boys, 6 girls) diagnosed over the period of 5 years (2009–2013). Results: The fetal presentation of the disorder was disclosed frequently: significant intrauterine growth retardation 13/13, oligo-/ anhydramnion 4/13, and premature delivery 9/13. The onset of disease was present within the neonatal period in all cases: muscular hypotonia 13/13 and hypertrophic cardiomyopathy 12/13 were the main clinical symptoms. Facial dysmorphism 6/13 and persistant pulmonary arterial hypertension in newborn 6/13 were also disclosed. All surviving children showed psychomotor delay and failure to thrive. Hepatopathy 5/13, as well as urogenital malformation (epi- or hypospadia and cryptorchidism) was found in 6/7 boys. Severe lactic acidosis 13/13 and mild to moderate hyperammonemia 13/13 were observed during detection of disorder.
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Organic acid profiles in urine revealed increased excretion of 3methylglutaconic acid in all investigated patients (range 13.4– 509.0 mol/mmol creat.), in some individuals mild orotic aciduria was present. Five patients died during the first month of life. All patients were homozygous for prevalent mutation 317-2ANG in TMEM70 gene and belonged to Romani ethnic group. Additionally, they descend exclusively from a small area in Northeast Slovakia. Conclusions: Our results support clinical and biochemical findings reported previously. The isolated ATP synthase deficiency due to mutation 317-2ANG in TMEM70 has been detected predominantly in the Romani people until now. It is suggested that the disorder could be frequent in Slovakia where this ethnic group represents approximately 8% of inhabitants. Interestingly, the disorder has not been disclosed in Romani living in other areas of Slovakia so far. doi:10.1016/j.clinbiochem.2014.04.040
Cod: 014 Bupropion exposure in an infant D. Colantonioa, S. Delaneyb, G. Neumana, S. Itoa a The Hospital for Sick Children, Canada b University of Toronto, Canada Background: The last two decades have seen a substantial increase in the rates of women breastfeeding. However, it has been reported that 66–80% of nursing women are on medication. While many drugs are safely taken by nursing mothers, there is accumulating evidence of toxicity in some breastfed infants. The uncertainty in the risk of drug exposure causes maternal non-adherence to therapy or avoidance of breastfeeding, a health issue uniquely affecting both mother and infant. The objective of this study is to investigate the risk of drug exposure in nursing infants. We present a proof-of-principle case of infant bupropion (BUP) exposure highlighting the importance and clinical applicability of this study. Methods: We established a drug safety monitoring program, Drugs in Lactation Analysis Consortium (DLAC), to measure several drugs commonly used by women breastfeeding. We worked to create a simplified drug extraction method using organic solvents to facilitate efficient drug extraction from both the lipid and aqueous phases of breast milk. Extraction efficiency and stability were determined. Methods were then developed to measure these drugs using LC–MS/MS. Case report: A 6.5 month old previously healthy infant presented to SickKids Hospital with vomiting and seizures. She was exclusively breastfed; her mother was taking escitalopram daily for several months, with the recent addition of BUP. The usual clinical workup was negative. The infant's urine was tested and was positive for BUP and escitalopram. Serial breast milk and serum samples were obtained and BUP and its major metabolite, hydroxybupropion, were measured using HPLC–MS/MS. Using a pharmacokinetic model, we determined that the BUP levels were significant around the time of the event. Discharge diagnosis was BUP-induced seizures. Conclusion: Given the increasing use of medication in nursing women, there is an urgency to investigate the potential adverse events associated with infant drug exposure through breast milk. Future investigations will focus on population pharmacokinetic modeling to simulate and estimate infant drug exposure and assess potential risks associated with drugs and breastfeeding. The data generated from this study will help guide decisions for drug use in nursing mothers. doi:10.1016/j.clinbiochem.2014.04.041
creatinine. The established method was used to determine creatinine in plasma samples from newborn infants. Results: The deproteinization step was optimized with pure methanol at a plasma:solvent ratio of 1:2. Chromatographic separation was achieved using an octadecyl (C18) reversed-phase column (100 mm × 4.6 mm) using isocratic elution. A mobile phase composed of phosphate buffer (pH 7.1)-methanol in the ratio of 99:1 (v/v) at a flow rate of 1 mL/min was found to be the most suitable for this separation. 10 μL of sample solution or standard solution was injected into the HPLC system and 235 nm was selected as the detection wavelength. Under these chromatographic conditions, creatinine had a retention time of approximately 2.1 min and the total run time was 4 min. The method proved to be linear in the clinical range of creatinine from 2.5 to 20 g/mL. Linear-regression analysis yielded a correlation coefficient of 0.999 and the regression equation was y = 1348,223 × −450,359. The relative standard deviations of within- and betweenassays were b10%. The method was also validated by spiked recoveries with an average recovery from 101.2 to 110.3% for the human plasma samples. No interference from endogenous substances or exogenous substances was observed. Using specimens from neonates, we compared this method with a routinely used automated alkaline picrate method. Conclusion: The proposed HPLC method is simple, rapid, and suitable for the accurate measurement of creatinine in human plasma especially in neonates without analytical interferences, while the Jaffé method may give in these circumstances inaccurate results.
doi:10.1016/j.clinbiochem.2014.04.039
Cod: 013 The thirteen new cases of isolated ATP synthase deficiency due to TMEM70 mutation in Slovakia: Clinical and biochemical findings D. Behulovab, C. Sebovab, S. Tarnokovab, K. Brennerovaa, D. Dolnikovaa, J. Zemand, M. Tesarovad, L. Potocnakovae, J. Chandogac a 1st Dept Ped, Univ Child Hosp, Bratislava, Slovakia b Centre Inher Metab Dis, Dept Lab Med, Univ Child Hosp, Bratislava, Slovakia c Dept Biol Gen and Clin Gen, Univ Hosp, Bratislava, Slovakia d Dept Ped, 1st Fac Med, Charles Univ, Prague, Czech Republic e Univ Child Hosp, Kosice, Slovakia Background: Isolated ATP synthase deficiency may be caused either by mutations in mtDNA or nuclear genes. The TMEM70 gene defect has been recently identified by Czech scientists as a novel nuclear origin of the disease. We report clinical symptoms and essential biochemical findings in patients with TMEM70 mutation detected lately in Slovakia (about 5.5 million inhabitants). Methods: Clinical data and metabolic profiles were evaluated in 13 Slovak patients (7 boys, 6 girls) diagnosed over the period of 5 years (2009–2013). Results: The fetal presentation of the disorder was disclosed frequently: significant intrauterine growth retardation 13/13, oligo-/ anhydramnion 4/13, and premature delivery 9/13. The onset of disease was present within the neonatal period in all cases: muscular hypotonia 13/13 and hypertrophic cardiomyopathy 12/13 were the main clinical symptoms. Facial dysmorphism 6/13 and persistant pulmonary arterial hypertension in newborn 6/13 were also disclosed. All surviving children showed psychomotor delay and failure to thrive. Hepatopathy 5/13, as well as urogenital malformation (epi- or hypospadia and cryptorchidism) was found in 6/7 boys. Severe lactic acidosis 13/13 and mild to moderate hyperammonemia 13/13 were observed during detection of disorder.
769
Organic acid profiles in urine revealed increased excretion of 3methylglutaconic acid in all investigated patients (range 13.4– 509.0 mol/mmol creat.), in some individuals mild orotic aciduria was present. Five patients died during the first month of life. All patients were homozygous for prevalent mutation 317-2ANG in TMEM70 gene and belonged to Romani ethnic group. Additionally, they descend exclusively from a small area in Northeast Slovakia. Conclusions: Our results support clinical and biochemical findings reported previously. The isolated ATP synthase deficiency due to mutation 317-2ANG in TMEM70 has been detected predominantly in the Romani people until now. It is suggested that the disorder could be frequent in Slovakia where this ethnic group represents approximately 8% of inhabitants. Interestingly, the disorder has not been disclosed in Romani living in other areas of Slovakia so far. doi:10.1016/j.clinbiochem.2014.04.040
Cod: 014 Bupropion exposure in an infant D. Colantonioa, S. Delaneyb, G. Neumana, S. Itoa a The Hospital for Sick Children, Canada b University of Toronto, Canada Background: The last two decades have seen a substantial increase in the rates of women breastfeeding. However, it has been reported that 66–80% of nursing women are on medication. While many drugs are safely taken by nursing mothers, there is accumulating evidence of toxicity in some breastfed infants. The uncertainty in the risk of drug exposure causes maternal non-adherence to therapy or avoidance of breastfeeding, a health issue uniquely affecting both mother and infant. The objective of this study is to investigate the risk of drug exposure in nursing infants. We present a proof-of-principle case of infant bupropion (BUP) exposure highlighting the importance and clinical applicability of this study. Methods: We established a drug safety monitoring program, Drugs in Lactation Analysis Consortium (DLAC), to measure several drugs commonly used by women breastfeeding. We worked to create a simplified drug extraction method using organic solvents to facilitate efficient drug extraction from both the lipid and aqueous phases of breast milk. Extraction efficiency and stability were determined. Methods were then developed to measure these drugs using LC–MS/MS. Case report: A 6.5 month old previously healthy infant presented to SickKids Hospital with vomiting and seizures. She was exclusively breastfed; her mother was taking escitalopram daily for several months, with the recent addition of BUP. The usual clinical workup was negative. The infant's urine was tested and was positive for BUP and escitalopram. Serial breast milk and serum samples were obtained and BUP and its major metabolite, hydroxybupropion, were measured using HPLC–MS/MS. Using a pharmacokinetic model, we determined that the BUP levels were significant around the time of the event. Discharge diagnosis was BUP-induced seizures. Conclusion: Given the increasing use of medication in nursing women, there is an urgency to investigate the potential adverse events associated with infant drug exposure through breast milk. Future investigations will focus on population pharmacokinetic modeling to simulate and estimate infant drug exposure and assess potential risks associated with drugs and breastfeeding. The data generated from this study will help guide decisions for drug use in nursing mothers. doi:10.1016/j.clinbiochem.2014.04.041