Impact of Newborn Screening and Early Dietary Management on Clinical Outcome of Patients with Long Chain 3-Hydroxyacyl-CoA Dehydrogenase Deficiency and Medium Chain Acyl-CoA Dehydrogenase Deficiency-A Retrospective Nationwide Study.

Long chain 3-hydroxyacyl-CoA dehydrogenase deficiency (LCHADD/MTPD) and medium chain acyl-CoA dehydrogenase deficiency (MCADD) were included in the expanded neonatal screening program (ENBS) in Czechia in 2009, allowing for the presymptomatic diagnosis and nutritional management of these patients. The aim of our study was to assess the nationwide impact of ENBS on clinical outcome. This retrospective study analysed acute events and chronic complications and their severity in pre-ENBS and post-ENBS cohorts. In total, 28 children (12 before, 16 after ENBS) were diagnosed with LCHADD/MTPD (incidence 0.8/100,000 before and 1.2/100,000 after ENBS). In the subgroup detected by ENBS, a significantly longer interval from birth to first acute encephalopathy was observed. In addition, improvement in neuropathy and cardiomyopathy (although statistically non-significant) was demonstrated in the post-ENBS subgroup. In the MCADD cohort, we included 69 patients (15 before, 54 after ENBS). The estimated incidence rose from 0.7/100,000 before to 4.3/100,000 after ENBS. We confirmed a significant decrease in the number of episodes of acute encephalopathy and lower proportion of intellectual disability after ENBS (p < 0.0001). The genotype-phenotype correlations suggest a new association between homozygosity for the c.1528C > G variant and more severe heart involvement in LCHADD patients.

Subclinical effects of long-chain fatty acid ß-oxidation deficiency on the adult heart: A case-control magnetic resonance study.

Cardiomyopathy can be a severe complication in patients with long-chain fatty acid ß-oxidation disorders (LCFAOD), particularly during episodes of metabolic derangement. It is unknown whether latent cardiac abnormalities exist in adult patients. To investigate cardiac involvement in LCFAOD, we used proton magnetic resonance imaging (MRI) and spectroscopy (1 H-MRS) to quantify heart function, myocardial tissue characteristics, and myocardial lipid content in 14 adult patients (two with long-chain 3-hydroxyacyl-CoA dehydrogenase deficiency (LCHADD); four with carnitine palmitoyltransferase II deficiency (CPT2D); and eight with very long-chain acyl-CoA dehydrogenase deficiency (VLCADD)) and 14 gender-, age-, and BMI-matched control subjects. Examinations included cine MRI, MR tagging, native myocardial T1 and T2 mapping, and localized 1 H-MRS at 3 Tesla. Left ventricular (LV) myocardial mass (P = .011) and the LV myocardial mass-to-volume ratio (P = .008) were higher in patients, while ejection fraction (EF) was normal (P = .397). LV torsion was higher in patients (P = .026), whereas circumferential shortening was similar compared with controls (P = .875). LV hypertrophy was accompanied by high myocardial T1 values (indicative of diffuse fibrosis) in two patients, and additionally a low EF in one case. Myocardial lipid content was similar in patients and controls. We identified subclinical morphological and functional differences between the hearts of LCFAOD patients and matched control subjects using state-of-the-art MR methods. Our results suggest a chronic cardiac disease phenotype and hypertrophic LV remodeling of the heart in LCFAOD, potentially triggered by a mild, but chronic, energy deficiency, rather than by lipotoxic effects of accumulating lipid metabolites.

The safety of Lipistart, a medium-chain triglyceride based formula, in the dietary treatment of long-chain fatty acid disorders: a phase I study.

BACKGROUND: Children with long-chain fatty acid ß-oxidation disorders (LCFAOD) presenting with clinical symptoms are treated with a specialist infant formula, with medium chain triglyceride (MCT) mainly replacing long chain triglyceride (LCT). It is essential that the safety and efficacy of any new specialist formula designed for LCFAOD be tested in infants and children. METHODS: In an open-label, 21-day, phase I trial, we studied the safety of a new MCT-based formula (feed 1) in six well-controlled children (three male), aged 7-13 years (median 9 years) with LCFAOD (very long chain acyl CoA dehydrogenase deficiency [VLCADD], n=2; long chain 3-hydroxyacyl CoA dehydrogenase deficiency [LCHADD], n=2; carnitine acyl carnitine translocase deficiency [CACTD], n=2). Feed 1 (Lipistart; Vitaflo) contained 30% energy from MCT, 7.5% LCT and 3% linoleic acid and it was compared with a conventional MCT feed (Monogen; Nutricia) (feed 2) containing 17% energy from MCT, 3% LCT and 1.1% linoleic acid. Subjects consumed feed 2 for 7 days then feed 1 for 7 days and finally resumed feed 2 for 7 days. Vital signs, blood biochemistry, ECG, weight, height, food/feed intake and symptoms were monitored. RESULTS: Five subjects completed the study. Their median daily volume of both feeds was 720 mL (range 500-1900 mL/day). Feed 1 was associated with minimal changes in tolerance, free fatty acids (FFA), acylcarnitines, 3-hydroxybutyrate (3-HB), creatine kinase (CK), blood glucose, liver enzymes and no change in an electrocardiogram (ECG). No child complained of muscle pain or symptoms associated with LCFAOD on either feed. CONCLUSIONS: This is the first safety trial reported of an MCT formula specifically designed for infants and children with LCFAOD. In this short-term study, it appeared safe and well tolerated in this challenging group.

Nutrient sensing in pancreatic islets: lessons from congenital hyperinsulinism and monogenic diabetes.

Pancreatic beta cells sense changes in nutrients during the cycles of fasting and feeding and release insulin accordingly to maintain glucose homeostasis. Abnormal beta cell nutrient sensing resulting from gene mutations leads to hypoglycemia or diabetes. Glucokinase (GCK) plays a key role in beta cell glucose sensing. As one form of congenital hyperinsulinism (CHI), activating mutations of GCK result in a decreased threshold for glucose-stimulated insulin secretion and hypoglycemia. In contrast, inactivating mutations of GCK result in diabetes, including a mild form (MODY2) and a severe form (permanent neonatal diabetes mellitus (PNDM)). Mutations of beta cell ion channels involved in insulin secretion regulation also alter glucose sensing. Activating or inactivating mutations of ATP-dependent potassium (KATP ) channel genes result in severe but completely opposite clinical phenotypes, including PNDM and CHI. Mutations of the other ion channels, including voltage-gated potassium channels (Kv 7.1) and voltage-gated calcium channels, also lead to abnormal glucose sensing and CHI. Furthermore, amino acids can stimulate insulin secretion in a glucose-independent manner in some forms of CHI, including activating mutations of the glutamate dehydrogenase gene, HDAH deficiency, and inactivating mutations of KATP channel genes. These genetic defects have provided insight into a better understanding of the complicated nature of beta cell fuel-sensing mechanisms.

Energy exchangers with LCT as a precision method for diet control in LCHADD.

Long-chain 3-hydroxyacyl-CoA dehydrogenase deficiency (LCHADD) is a rare genetic disease. The LCHADD treatment is mainly based on special diet. In this diet, energy from long-chain triglycerides (LCT) cannot exceed 10%, however energy intake from the consumption of medium-chain triglycerides (MCTs) should increase. The daily intake of energy should be compatible with energy requirements and treatment should involve frequent meals including during the night to avoid periods of fasting. In fact, there are no recommendations for total content of LCT in all of the allowed food in the LCHADD diet. The aim of the study was to present a new method of diet composition in LCHADD with the use of blocks based on energy exchangers with calculated LCT content. In the study, the diet schema was shown for calculating the energy requirements and LCT content in the LCHADD diet. How to create the diet was also shown, based on a food pyramid developed for patients with LCHADD. The blocks will make it possible, in a quick and simple way, to create a balanced diet which provides adequate energy value, essential nutrients and LCT content. This method can be used by doctors and dietitians who specialize in treating rare metabolic diseases. It can also be used by patients and their families for accurate menu planning with limited LCT content.

[Variation of long-chain 3-hydroxyacyl-CoA dehydrogenase DNA methylation in placenta of different preeclampsia-like mouse models].

OBJECTIVE: By detecting the variation of long-chain 3-hydroxyacyl-CoA dehydrogenase (LCHAD) DNA methylation in preeclampsia-like mouse models generated by different ways, to explore the roles of multifactor and multiple pathways in preeclampsia pathogenesis on molecular basis. METHODS: Established preeclampsia-like mouse models in different ways and divided into groups as follows: (1) Nw-nitro-L-arginine-methyl ester (L-NAME) group: wild-type pregnant mouse received subcutaneous injection of L-NAME; (2) lipopolysaccharide (LPS) group: wild-type pregnant mouse received intraperitoneal injection of LPS; (3) apolipoprotein C-III (ApoC3) group: ApoC3 transgenic pregnant mouse with dysregulated lipid metabolism received subcutaneous injection of L-NAME; (4) ß2 glycoprotein I (ß-2GPI) group: wild-type pregnant mouse received subcutaneous injection of ß-2GPI. According to the first injection time (on day 3, 11, 16 respectively), the L-NAME, LPS and ApoC3 groups were further subdivided into: pre-implantation (PI) experimental stage, early gestation (EG) experimental stage, and late gestation (LG) experimental stage. ß-2GPI group was only injected before implantation. LCHAD gene methylation levels in placental were detected in different experimental stage. Normal saline control groups were set within wild-type and ApoC3 transgenic pregnant mice simultaneously. RESULTS: (1) CG sites in LCHAD DNA: 45 CG sites were detected in the range of 728 bp before LCHAD gene transcription start site, the 5, 12, 13, 14, 15, 16, 19, 24, 25, 27, 28, 29, 30, 31, 32, 34, 35, 43 CG sites were complex sites which contained two or more CG sequences, others were single site which contained one CG sequence. The 3, 5, 6, 11, 13, 14, 18, 28 sites in L-NAME, LPS, ApoC3 and ß-2GPI groups showed different high levels of methylation; the 16, 25, 31, 42, 44 sites showed different low levels of methylation; other 32 sites were unmethylated. (2) Comparison of LCHAD gene methylation between different groups: the methylation levels of LCAHD gene at 3, 11, 13, 14, 18 sites in L-NAME, LPS, ApoC3 and ß-2GPI groups were significantly higher than those in the normal saline control group (P < 0.05); and the methylation levels of 42, 44 sites in these groups were significantly lower than those in the normal saline control group (P < 0.05). (3) Methylation of LCHAD gene at the same site between different experimental stages: ① The 3, 11, 18 sites of EG experimental stage was significantly lower than PI and LG experimental stage in L-NAME group (P < 0.05); the 3, 11, 18 sites of PI experimental stage was significantly lower than EG and LG experimental stage in LPS group (P < 0.05); these sites of PI experimental stage was significantly higher than EG and LG experimental stages in ApoC3 group (P < 0.05). ② The methylation of site 5 in L-NAME and LPS groups were significantly higher than that of the normal saline control group (P < 0.05), and the LG experimental stages were significantly higher than other stages, but in ApoC3 group, only PI and EG stages were significantly higher than the normal saline control group (P < 0.05). ③ At site 6 in L-NAME group which showed high methylation level was significantly higher than the same site in other groups which showed low methylation level (P < 0.05). ④ At 13, 14 sites, earlier preeclampsia onset caused a lower methylation level in L-NAME group, but PI experimental stage was significantly higher than EG and LG experimental stages in LPS group (P < 0.05), EG experimental stage was significantly higher than PI and LG experimental stages in ApoC3 group (P < 0.05). ⑤ At site 28, earlier preeclampsia onset caused a higher methylation level in L-NAME group, but PI experimental stage was significantly lower than EG and LG experimental stages in LPS group (P < 0.05), EG experimental stage was significantly higher than PI and LG experimental stages in ApoC3 group (P < 0.05). ⑥ The 16, 25, 31 sites in ApoC3 group were significantly higher than other groups (P < 0.05). ⑦ At site 42 in ß-2GPI group was unmethylated, but it in other groups showed low methylation level, the methylation level of site 42 in ß-2GPI group was significantly lower than that in other groups (P < 0.05). CONCLUSIONS: The methylation of 6 and 42 CG sites may be related to LCHAD gene expression in placenta of L-NAME and ß-2GPI induced preeclampsia-like models respectively; LCHAD gene expression and DNA methylation may not have obvious correlation in LPS and ApoC3 induced preeclampsia-like models. Differences exist in LCHAD DNA methylation in preeclampsia-like models generated by different ways, revealed a molecular basis to expand our understanding of the multi-factorial pathogenesis of preeclampsia.

A Deep Intronic HADH Splicing Mutation (c.636+471G>T) in a Congenital Hyperinsulinemic Hypoglycemia Case: Long Term Clinical Course.

Unlike other congenital fatty acid oxidation defects, short-chain L-3-hydroxyacyl-CoA (SCHAD, HADH) deficiency is characterised by hypoglycemia with hyperinsulinism in the neonatal or infancy periods. The long-term and detailed clinical progression of the disease is largely unknown with almost 40 patients reported and only a few patients described clinically. We present clinical and laboratory findings together with the long-term clinical course of a case with a deep intronic HADH splicing mutation (c.636+471G>T) causing neonatal-onset hyperinsulinemic hypoglycemia with mild progression.

Clinical outcome, biochemical and therapeutic follow-up in 14 Austrian patients with Long-Chain 3-Hydroxy Acyl CoA Dehydrogenase Deficiency (LCHADD).

BACKGROUND: LCHADD is a long-fatty acid oxidation disorder with immediate symptoms and long-term complications. We evaluated data on clinical status, biochemical parameters, therapeutic regimens and outcome of Austrian LCHADD patients. STUDY DESIGN: Clinical and outcome data including history, diagnosis, short- and long-term manifestations, growth, psychomotor development, hospitalizations, therapy of 14 Austrian patients with LCHADD were evaluated. Biochemically, we evaluated creatine kinase (CK) and acyl carnitine profiles. RESULTS: All LCHADD patients are homozygous for the common mutation. Three are siblings. Diagnosis was first established biochemically. Nine/14 (64%) were prematures, with IRDS occurring in six. In nine (64%), diagnosis was established through newborn screening, the remaining five (36%) were diagnosed clinically. Four pregnancies were complicated by HELLP syndrome, one by preeclampsia. In two, intrauterine growth retardation and placental insufficiency were reported. Five were diagnosed with hepatopathy at some point, seven with cardiomyopathy and eight with retinopathy, clinically relevant only in one patient. Polyneuropathy is only present in one. Three patients have a PEG, one is regularly fed via NG-tube. Growth is normal in all, as well as psychomotor development, except for two extremely premature girls. In 11 patients, 165 episodes with elevated creatine kinase concentrations were observed with 6-31 (median 14) per patient; three have shown no elevated CK concentrations. Median total carnitine on therapy was 19 µmol/l (range 11-61). For 14 patients, there have been 181 hospitalizations (median 9 per patient), comprising 1337 in-patient-days. All centres adhere to treatment with a fat-defined diet; patients have between 15% and 40% of their energy intake from fat (median 29%), out of which between 20% and 80% are medium-chain triglycerides (MCT) (median 62%). Four patients have been treated with heptanoate (C7). CONCLUSION: Our data show LCHADD outcome can be favourable. Growth and psychomotor development is normal, except in two prematures. Frequency of CK measurements decreases with age, correlating with a decreasing number of hospitalizations. About 50% develop complications affecting different organ systems. There is no relevant difference between the patients treated in the respective centers. Concluding from single case reports, anaplerotic therapy with heptanoate should be further evaluated.

[Expression of long chain fatty acid oxidase in maternal and fetal tissues in preeclampsia-like mouse model in mid-gestation].

OBJECTIVE: To explore the protein expression and distribution of long-chain 3-hydroxyacyl-CoA dehydrogenase (LCHAD) in various maternal and fetal tissues in preeclampsia-like and normal pregnant mouse models during the middle trimester. METHODS: C57BL/6J mice were divided into preeclampsia-like experimental group with Nw-nitro-L-arginine-methyl ester injection and normal pregnancy control group with normal saline injection. Samples were taken at Day 14 of gestation. Immunohistochemistry was used to detect the LCHAD protein expression and distribution in various maternal and fetal tissues. RESULTS: The mean arterial pressure was (115.6 ± 3.3) mmHg (1 mmHg = 0.133 kPa) in experimental group and (96.2 ± 4.9) mmHg in control group (P < 0.05). The urine protein contents were (97.0 ± 4.3) µg/g body weight/24h in experimental group and (60.8 ± 4.9) µg/g body weight/24h in control group (P < 0.05). In both groups, LCHAD protein was expressed in maternal liver, kidney, heart and placenta tissues during the middle trimester. And maternal hepatic tissue, myocardial tissue, renal tubule and spongiotrophoblast showed a strong positive expression, placental labyrinth layer a moderate positive expression and glomerulus a weakly positive expression. LCHAD expression of maternal liver and placenta decreased significantly in experimental group (P < 0.05). At Day 14 of pregnancy, LCHAD was expressed in fetal liver, kidney, heart, lung tissue and neural retina. And renal tubule, pulmonary epithelial tissue and neural retina showed a strong positive expression, fetal liver a moderate positive expression and myocardial tissue and glomerulus a weakly positive expression. There was no significant inter-group difference in fetal tissues. CONCLUSION: LCHAD is expressed and distributed widely in maternal and fetal tissues during the middle trimester. And it may play an important role in maternal metabolism and placenta-fetus development during pregnancy. There is an abnormal protein expression LCHAD in maternal liver and placenta with preeclampsia-like changes.

[The changes of LCHAD in preeclampsia with different clinical features and the correlation with NADPH P47-phox, p38MAPK-α, COX-2 and serum FFA and TG].

OBJECTIVE: To investigate the changes of fatty acid oxidase in the placenta of preeclampsia cases with different clinical features, and the relationship with oxidative stress and inflammatory response. To study the correlation of serum free fatty acid (FFA) and triglycerides (TG) level in early second trimester with the molecular changes of the long-chain fatty acid oxidase in the third trimester. METHODS: This was prospective cohort study, in which cases with singleton pregnancies who archived in Haidian Maternal and Children's Hospital, Beijing, from January 1st 2012 to May 31st, with regular prenatal care were included. Doppler ultrasound was used for screening for the presence of early diastolic notch of uterine artery at 22-24 weeks of gestation. All the 101 cases with the early diastolic notch of uterine artery were included as the notch group, and 377 cases without the early diastolic notch of uterine artery were included as the non-notch group. The perinatal outcomes and the incidence of hypertensive disorders in pregnancy of the two groups were observed. The serum level of FFA and TG was tested, and the mRNA and protein expression of long-chain 3-hydroxyacyl-CoA dehydrogenase (LCHAD), P47-phox subunit of nicotinamide adenine dinucleotide phosphate (NADPH) oxidase, p38 mitogen-activated protein kinase a (p38MAPK-α) and cyclooxygenase-2 (COX-2) were detected using real-time quantitative PCR and western blot. The relationship between serum level of FFA and TG and the mRNA and protein expression of LCHAD, NADPH P47-phox, p38MAPK-α and COX-2 of the placental tissue specimens were analyzed. RESULTS: (1) In the notch group, there were 9 cases of early-onset preeclampsia, 15 cases of late-onset preeclampsia and 10 cases of gestational hypertension;and there were 8 cases of late-onset preeclampsia and 18 cases of gestational hypertension in the non-notch group. 15 cases with normal blood pressure in each group were randomly selected as the control group. (2)The serum level of TG of cases of early-onset preeclampsia, late-onset preeclampsia and gestational hypertension in the notch group were (2.0 ± 0.8), (1.8 ± 0.6)and (1.9 ± 0.7)mmol/L, and that of FFA were(0.68 ± 0.26), (0.52 ± 0.10) and (0.52 ± 0.17)mmol/L, respectively. The serum level of TG of cases of late-onset preeclampsia and gestational hypertension in the non-notch group were (1.6 ± 0.6) and (1.4 ± 0.4)mmol/L, and that of FFA were (0.49 ± 0.11) and (0.48 ± 0.05)mmol/L, respectively. The serum level of TG and FFA in the control group were (1.4 ± 0.5) and (0.52 ± 0.06)mmol/L, respectively. The TG level of the notch group was higher than that of the control group, and the difference was statistically significant (P < 0.05). The FFA level of the early-onset preeclampsia in the notch group was higher than that of late-onset preeclampsia in the notch group, late-onset preeclampsia in the non-notch group and the control group, and the difference was statistically significant (P < 0.05). (3) The mRNA expression of LCHAD in the placenta of early-onset preeclampsia in the notch group was significantly lower than that of the late-onset preeclampsia in the notch group, late-onset preeclampsia in the non-notch group and the control group (P < 0.01). The mRNA expression of NADPH P47-phox of the early-onset preeclampsia in the notch group were significantly higher than that of late-onset preeclampsia in the notch group, late-onset preeclampsia in the non-notch group and the control group (P < 0.01). The mRNA expression of p38MAPK-α of the early-onset preeclampsia in the notch group were significantly higher than that of late-onset preeclampsia in the notch group, late-onset preeclampsia in the non-notch group and the control group (P < 0.01). The mRNA expression of COX-2 of the early-onset preeclampsia in the notch group were significantly higher than that of late-onset preeclampsia in the notch group, late-onset preeclampsia in the non-notch group and the control group (P < 0.01). (4)The protein expression of LCHAD in the placenta of early-onset preeclampsia in the notch group, late-onset preeclampsia in the notch group and gestational hypertension in the notch group were significantly lower than that of the control group (P < 0.01); and the protein expression of LCHAD in the placenta of early-onset preeclampsia in the notch group was significantly lower than that of late-onset preeclampsia in the non-notch group (P < 0.01). The protein expression of NADPH P47-phox in the placenta of early-onset preeclampsia in the notch group was significantly higher than that of late-onset preeclampsia in the non-notch group and control group (P < 0.05). The protein expression of p38MAPK-α in the placenta of early-onset preeclampsia in the notch group was significantly higher than that of late-onset preeclampsia in the notch group, late-onset preeclampsia in the non-notch group and control group (P < 0.01). The protein expression of COX-2 in the placenta of early-onset preeclampsia in the notch group, late-onset preeclampsia in the notch group, gestational hypertension in the notch group, late-onset preeclampsia in the non-notch group, and gestational hypertension in the non-notch group, were significantly higher than that of control group (P < 0.01). (5)The blood concentration of maternal FFA in the early-onset preeclampsia in the notch group was significantly negatively correlated with the mRNA and protein expression of placental LCHAD (r = -0.810, -0.932, P < 0.01). There was no correlation between maternal TG level and the mRNA and protein expression of placental LCHAD in each group(P > 0.05). (6)The mRNA expression of placental LCHAD in the early-onset preeclampsia in the notch group was significantly negatively correlated with the mRNA expression of placental NADPH P47-phox and COX-2 (r = - 0.877, -0.762, P < 0.05). The mRNA expression of placental LCHAD in the control group was significantly negatively correlated with the mRNA expression of placental COX-2 (r = -0.565, P < 0.01). The protein expression of placental LCHAD in the early-onset preeclampsia in the notch group was significantly negatively correlated with the protein expression of NADPH P47-phox (r = -0.818, P < 0.01). The protein expression of placental LCHAD in the control group was significantly negatively correlated with the protein expression of COX-2 (r = -0.502, P < 0.01). CONCLUSIONS: The placental mRNA and protein expression of long-chain fatty acid oxidation enzymes were different in different clinical features of preeclampsia, which were reduced more obviously in the early-onset preeclampsia in the notch group than that of the late-onset preeclampsia in the notch group, and were negatively correlated with the elevated serum FFA level, significantly enhanced oxidative stress and inflammatory response, but with no correlation with serum TG level.

Uncoupling, metabolic inhibition and induction of mitochondrial permeability transition in rat liver mitochondria caused by the major long-chain hydroxyl monocarboxylic fatty acids accumulating in LCHAD deficiency.

Patients with long-chain 3-hydroxy-acyl-CoA dehydrogenase (LCHAD) deficiency commonly present liver dysfunction whose pathogenesis is unknown. We studied the effects of long-chain 3-hydroxylated fatty acids (LCHFA) that accumulate in LCHAD deficiency on liver bioenergetics using mitochondrial preparations from young rats. We provide strong evidence that 3-hydroxytetradecanoic (3HTA) and 3-hydroxypalmitic (3HPA) acids, the monocarboxylic acids that are found at the highest tissue concentrations in this disorder, act as metabolic inhibitors and uncouplers of oxidative phosphorylation. These conclusions are based on the findings that these fatty acids decreased ADP-stimulated (state 3) and uncoupled respiration, mitochondrial membrane potential and NAD(P)H content, and, in contrast, increased resting (state 4) respiration. We also verified that 3HTA and 3HPA markedly reduced Ca2+ retention capacity and induced swelling in Ca2+-loaded mitochondria. These effects were mediated by mitochondrial permeability transition (MPT) induction since they were totally prevented by the classical MPT inhibitors cyclosporin A and ADP, as well as by ruthenium red, a Ca2+ uptake blocker. Taken together, our data demonstrate that the major monocarboxylic LCHFA accumulating in LCHAD deficiency disrupt energy mitochondrial homeostasis in the liver. It is proposed that this pathomechanism may explain at least in part the hepatic alterations characteristic of the affected patients.

Increased and early lipolysis in children with long-chain 3-hydroxyacyl-CoA dehydrogenase (LCHAD) deficiency during fast.

Children with long-chain 3-hydroxyacyl-CoA dehydrogenase deficiency (LCHAD) have a defect in the degradation of long-chain fatty acids and are at risk of hypoketotic hypoglycemia and insufficient energy production as well as accumulation of toxic fatty acid intermediates. Knowledge on substrate metabolism in children with LCHAD deficiency during fasting is limited. Treatment guidelines differ between centers, both as far as length of fasting periods and need for night feeds are concerned. To increase the understanding of fasting intolerance and improve treatment recommendations, children with LCHAD deficiency were investigated with stable isotope technique, microdialysis, and indirect calometry, in order to assess lipolysis and glucose production during 6 h of fasting. We found an early and increased lipolysis and accumulation of long chain acylcarnitines after 4 h of fasting, albeit no patients developed hypoglycemia. The rate of glycerol production, reflecting lipolysis, averaged 7.7 ± 1.6 µmol/kg/min, which is higher compared to that of peers. The rate of glucose production was normal for age; 19.6 ± 3.4 µmol/kg/min (3.5 ± 0.6 mg/kg/min). Resting energy expenditure was also normal, even though the respiratory quotient was increased indicating mainly glucose oxidation. The results show that lipolysis and accumulation of long chain acylcarnitines occurs before hypoglycemia in fasting children with LCHAD, which may indicate more limited fasting tolerance than previously suggested.

Transient central diabetes insipidus induced by ketamine infusion.

OBJECTIVE: Report a case of central diabetes insipidus (DI) associated with ketamine infusion. CASE SUMMARY: A 2-year-old girl with long-chain 3-hydroxyacyl-CoA dehydrogenase deficiency and stable hypertrophic cardiomyopathy was admitted to the pediatric intensive care with pneumonia. She subsequently developed respiratory failure and required intubation. Continuous ketamine infusion was used for the sedation and facilitation of mechanical ventilation. Shortly after infusion of ketamine, the patient developed DI and responded appropriately to vasopressin. DISCUSSION: The Naranjo adverse drug reaction probability scale indicated a probable relationship between the development of central DI and ketamine. The most likely mechanism involves ketamine's antagonist action on N-methyl-d-aspartate receptors, resulting in inhibition of glutamate-stimulated arginine vasopressin release from the neurohypophysis. CONCLUSION: This is the second case report of ketamine-induced central DI and the only report in children. Clinicians who sedate children with continuous ketamine infusions should monitor patients for developing signs and symptoms of DI by measuring serum sodium and urine output prior to, during, and after ketamine infusion in order to make a timely diagnosis of this potentially serious complication.

Systematic review and meta-analysis to estimate the birth prevalence of five inherited metabolic diseases.

Many newborn screening programmes now use tandem mass spectrometry in order to screen for a variety of diseases. However, countries have embraced this technology with a differing pace of change and for different conditions. This has been facilitated by the ability of this diagnostic method to limit analysis to specific metabolites of interest, enabling targeted screening for particular conditions. MS/MS was introduced in 2009 in England to implement newborn bloodspot screening for medium chain acyl-CoA dehydrogenase deficiency (MCADD) raising the possibility of screening for other inherited metabolic disorders. Recently, a pilot screening programme was conducted in order to evaluate the health and economic consequences of screening for five additional inherited metabolic disorders in England. As part of this study we conducted a systematic review and meta-analysis to estimate the birth prevalence of these conditions: maple syrup urine disease, homocystinuria (pyridoxine unresponsive), glutaric aciduria type I, isovaleric acidaemia and long-chain 3-hydroxyacyl-CoA dehydrogenase deficiency including trifunctional protein deficiency. We identified a total of 99 studies that were able to provide information on the prevalence of one or more of the disorders. The vast majority of studies were of screening programmes with some reporting on clinically detected cases.

Mitochondrial bioenergetics deregulation caused by long-chain 3-hydroxy fatty acids accumulating in LCHAD and MTP deficiencies in rat brain: a possible role of mPTP opening as a pathomechanism in these disorders?

Long-chain 3-hydroxylated fatty acids (LCHFA) accumulate in long-chain 3-hydroxy-acyl-CoA dehydrogenase (LCHAD) and mitochondrial trifunctional protein (MTP) deficiencies. Affected patients usually present severe neonatal symptoms involving cardiac and hepatic functions, although long-term neurological abnormalities are also commonly observed. Since the underlying mechanisms of brain damage are practically unknown and have not been properly investigated, we studied the effects of LCHFA on important parameters of mitochondrial homeostasis in isolated mitochondria from cerebral cortex of developing rats. 3-Hydroxytetradecanoic acid (3 HTA) reduced mitochondrial membrane potential, NAD(P)H levels, Ca(2+) retention capacity and ATP content, besides inducing swelling, cytochrome c release and H2O2 production in Ca(2+)-loaded mitochondrial preparations. We also found that cyclosporine A plus ADP, as well as ruthenium red, a Ca(2+) uptake blocker, prevented these effects, suggesting the involvement of the mitochondrial permeability transition pore (mPTP) and an important role for Ca(2+), respectively. 3-Hydroxydodecanoic and 3-hydroxypalmitic acids, that also accumulate in LCHAD and MTP deficiencies, similarly induced mitochondrial swelling and decreased ATP content, but to a variable degree pending on the size of their carbon chain. It is proposed that mPTP opening induced by LCHFA disrupts brain bioenergetics and may contribute at least partly to explain the neurologic dysfunction observed in patients affected by LCHAD and MTP deficiencies.