Neonatal screening for defects of the mitochondrial trifunctional protein

Long-chain l-3-hydroxyacyl-CoA dehydrogenase (LCHAD) deficiency has been included in the routine neonatal screening program by the German screening commission. As tandem mass spectrometry (TMS) does not discriminate between the different defects of the mitochondrial trifunctional protein (MTP) screening for isolated LCHAD deficiency includes the detection of long-chain 3-ketoacyl-CoA thiolase and complete MTP deficiencies as well. We identified 11 patients with abnormalities of the MTP out of 1.2 million newborns screened in our laboratory during the last 6 years. Treatment was started on the day the screening result was obtained (day 3 to day 9 of life). Seven of these newborns developed satisfactorily during an observation period of up to 64 months. They had isolated LCHAD deficiency, four of them caused by the typical mutation (1528 G>C), three others had no molecular genetic analysis done or were shown to have previously unknown mutations. Four children did not survive, two of them showing complete deficiency of MTP and two showing deficiency of long-chain 3-ketoacyl-CoA thiolase. We conclude that, despite the rarity of the disease, screening for MTP deficiencies is justified based on the following criteria: improved quality of life for patients with isolated LCHAD deficiency, absence of stigmatisation of babies showing mild variants without necessity of treatment, no significant increase of the total number of false positive screening results, no false negative results to our knowledge. Finally, extension of analysis to MTP deficiencies is achieved without additional costs for screening laboratories already using TM

Accumulation of very long-chain fatty acids does not affect mitochondrial function in adrenoleukodystrophy protein deficiency

X-linked adrenoleukodystrophy (X-ALD, OMIM 300100) is a severe inherited neurodegenerative disease, associated with the accumulation of very long-chain fatty acids (VLCFA). The recent unexpected observation that the accumulation of VLCFA in tissues of the Abcd1-deficient mouse model for X-ALD is not due to a deficiency in VLCFA degradation, led to the hypothesis that mitochondrial abnormalities might contribute to X-ALD pathology. Here, we report that in spite of substantial accumulation of VLCFA in whole muscle homogenates, normal VLCFA levels were detected in mitochondria obtained by organellar fractionation. Polarographic analyses of the respiratory chain as well as enzymatic assays of isolated muscle mitochondria revealed no differences between X-ALD and control mice. Moreover, analysis by electron microscopy, revealed normal size, structure and localization of mitochondria in muscle of both groups. Similar to the results obtained in skeletal muscle, the mitochondrial enzyme activities in brain homogenates of Abcd1-deficient and wild-type animals also did not differ. Finally, studies on mitochondrial oxidative phosphorylation in permeabilized human skin fibroblasts of X-ALD patients and controls revealed no abnormalities. Thus, we conclude that the accumulation of VLCFA per se does not cause mitochondrial abnormalities and vice versa-mitochondrial abnormalities are not responsible for the accumulation of VLCFA in X-ALD mic

Future steps in cardio-oncology—a national multidisciplinary survey among healthcare professionals in the Netherlands

Background: The awareness of cancer therapy–related adverse cardiac effects is fueled by recent literature on cardiotoxicity incidence and detection strategies. Although this influences the sense of urgency, in current practice, cardiotoxicity monitoring and treatment is not structurally performed. With this study, we aimed to evaluate current perspectives on cardio-oncology and to assess needs, ultimately to determine an agenda for improvements in current practice. Material and methods: A national multidisciplinary 36-question survey was conducted. The survey was developed by a multidisciplinary team, theoretically based on an implementation checklist and distributed by email, through cardiology and oncology societies as well as social media. Results: One hundred ninety professionals completed the survey, of which 66 were cardiologists, 66 radiation oncologists, and 58 medical oncologists and hematologists. Many professionals were unaware of their specialisms’ cardio-oncology guidelines: 62.1% of cardiologists and 29.3% of the hematologists and medical oncologists respectively. Many cardiologists (N = 46; 69.7%), radiation oncologists (N = 45; 68.2%), and hematologists and medical oncologists (N = 38; 65.5%) expressed that they did not have sufficient knowledge to treat cardio-oncology patients and would either refer a patient or aspire to gain more knowledge on the topic. Conclusion: The field of cardio-oncology is advancing rapidly, with progress in stratification and detection strategies leading to the development of new guidelines and consensus statements. However, the application of these guidelines in current practice appears to be lagging. Professionals express a need for additional training and a practical guideline including risk stratification, monitoring, and treatment strategies. Multidisciplinary discussion and consensus on cardio-oncology care is vital to improve implementation of cardio-oncology guidelines, ultimately to improve cardiac care for oncology patients