Health-related quality of life among adults with diverse rare disorders

Kathleen R. Bogart and Veronica L. Irvin; Orphanet Journal of Rare Diseases 201712:177 doi:10.1186/s13023-017-0730-1

Twenty-five to 30 million Americans live with a rare disease (RD) and share challenges unique to RD. The majority of research on RDs has focused on etiology, treatment and care, while the limited health-related quality of life (HRQL) research has been restricted to single RDs, small samples, or non-validated measures. This study reports HRQL among adults with diverse RDs, and compares their scores to those of the U.S. population and people with common chronic health conditions.

Biochemical Analyses of Human Iron–Sulfur Protein Biogenesis and of Related Diseases

Oliver Stehling, Viktoria D. Paul, Janina Bergmann, Somsuvro Basu, Roland Lill, Methods in Enzymology, Academic Press, ISSN 0076-6879, doi:10.1016/bs.mie.2017.11.004.

Maturation of Fe/S proteins in mammals is an intricate process mediated by two assembly systems located in the mitochondrial and cytosolic–nuclear compartments. Malfunction particularly of the mitochondrial system gives rise to severe neurological, metabolic, or hematological disorders, often with fatal outcome. In this chapter, we describe approaches for the differential biochemical investigation of cellular Fe/S protein maturation in mitochondria, cytosol, and nucleus. The analyses may also facilitate the identification of the affected Fe/S protein assembly step in diseased state. As Fe/S cluster insertion into target apoproteins is a frequent determinant of protein stability, examination of protein steady-state levels in biological samples frequently permits reliable first clues about the maturation process. In some specific cases, this approach allows the assessment of enzymatic or regulatory functions of Fe/S proteins, including the formation of lipoate cofactor by mitochondrial lipoic acid synthase or the posttranscriptional regulation of transferrin receptor and ferritin expression by the cytosolic iron regulatory proteins. More direct Fe/S protein maturation assays like enzymatic analyses may further validate the observed maturation defects. Here, we present a simple protocol for the determination of dihydropyrimidine dehydrogenase enzyme activity by thin-layer chromatography. In order to directly monitor Fe/S cluster insertion into target apoproteins, we have developed a 55Fe radiolabeling technique tracing the in vivo Fe/S cofactor formation in mammalian tissue culture. The combination of the presented techniques represents a comprehensive strategy to assess the multiple facets of Fe/S protein assembly for both mechanistic analyses and for the elucidation of specific defects in Fe/S diseases.

Computational drug repositioning for rare diseases in the era of precision medicine

Brian Delavan, Ruth Roberts, Ruili Huang, Wenjun Bao, Weida Tong, Zhichao Liu, Drug Discovery Today, 2017, , ISSN 1359-6446, doi:10.1016/j.drudis.2017.10.009.

There are tremendous unmet needs in drug development for rare diseases. Computational drug repositioning is a promising approach and has been successfully applied to the development of treatments for diseases. However, how to utilize this knowledge and effectively conduct and implement computational drug repositioning approaches for rare disease therapies is still an open issue. Here, we focus on the means of utilizing accumulated genomic data for accelerating and facilitating drug repositioning for rare diseases. First, we summarize the current genome landscape of rare diseases. Second, we propose several promising bioinformatics approaches and pipelines for computational drug repositioning for rare diseases. Finally, we discuss recent regulatory incentives and other enablers in rare disease drug development and outline the remaining challenges.

Depressive symptoms in Friedreich ataxia

Antonieta Nieto, Atteneri Hernández-Torres, Javier Pérez-Flores, Fernando Montón, International Journal of Clinical and Health Psychology, Available online 8 December 2017, ISSN 1697-2600, doi:10.1016/j.ijchp.2017.11.004.

Almost no attention has been paid to depression in Friedreich ataxia (FRDA), a highly disabling cerebellar degenerative disease. Our aim was to study the presence and the profile of depressive symptoms in FRDA and their relationship with demographic-disease variables and cognitive processing speed. Method: The study groups consisted of 57 patients with a diagnosis of FRDA. The Beck Depression Inventory-II was used to assess symptoms of depression. Speed of information processing was measured with a Choice Reaction time task. The mean BDI score for patients was significantly higher than the mean score in the general population. Twenty one percent of participants scored in the moderate/severe range. A Cognitive-Affective score and a Somatic-Motivational score was calculated for each patient. Patients’ scores in both dimensions were significantly higher than the scores in the general population. Demographic and disease variables were not related with symptoms of depression, except for severity of ataxia. Depressive symptoms predict cognitive reaction times. The greater proportion of variance was explained by the Cognitive-Affective dimension. Our data show that both somatic-motivational and cognitive affective symptoms of depression are frequent in individuals with FRDA. In addition, depressive symptoms may influence cognition, especially, the cognitive and affective symptoms.

Mitochondrial pore opening and loss of Ca2 + exchanger NCLX levels occur after frataxin depletion

R. Purroy, E. Britti, F. Delaspre, J. Tamarit, J. Ros, Biochimica et Biophysica Acta (BBA) - Molecular Basis of Disease, Available online 6 December 2017, ISSN 0925-4439, doi:10.1016/j.bbadis.2017.12.005.

Frataxin-deficient neonatal rat cardiomyocytes and dorsal root ganglia neurons have been used as cell models of Friedreich ataxia. In previous work we show that frataxin depletion resulted in mitochondrial swelling and lipid droplet accumulation in cardiomyocytes, and compromised DRG neurons survival. Now, we show that these cells display reduced levels of the mitochondrial calcium transporter NCLX that can be restored by calcium-chelating agents and by external addition of frataxin fused to TAT peptide. Also, the transcription factor NFAT3, involved in cardiac hypertrophy and apoptosis, becomes activated by dephosphorylation in both cardiomyocytes and DRG neurons. In cardiomyocytes, frataxin depletion also results in mitochondrial permeability transition pore opening. Since the pore opening can be inhibited by cyclosporin A, we show that this treatment reduces lipid droplets and mitochondrial swelling in cardiomyocytes, restores DRG neuron survival and inhibits NFAT dephosphorylation. These results highlight the importance of calcium homeostasis and that targeting mitochondrial pore by repurposing cyclosporin A, could be envisaged as a new strategy to treat the disease.

Friedreich ataxia: Clinical feature and electrophysiological symptoms

Oguri M. ; J Neurosci Rural Pract [serial online] 2017 [cited 2017 Dec 6];8:691-2. DOI: 10.4103/jnrp.jnrp_248_17

The ataxia is slowly progressive and involves the lower extremities to a greater degree than the upper extremities. In general, results of electrophysiologic studies including visual, auditory brainstem, and somatosensory-evoked potentials are often abnormal.

Iron-induced oligomerization of human FXN 81-210 and bacterial CyaY frataxin and the effect of iron chelators

Eva-Christina Ahlgren, Mostafa Fekry, Mathias Wiemann, Christopher A. Söderberg, Katja Bernfur, Olex Gakh, Morten Rasmussen, Peter Højrup, Cecilia Emanuelsson, Grazia Isaya, Salam Al-Karadaghi. PLoS ONE 12(12): e0188937. doi:10.1371/journal.pone.0188937

Patients suffering from the progressive neurodegenerative disease Friedreich’s ataxia have reduced expression levels of the protein frataxin. Three major isoforms of human frataxin have been identified, FXN42-210, FXN56-210 and FXN81-210, of which FXN81-210 is considered to be the mature form.

C-Path And FARA Announce Collaborative Data Aggregation Project For Friedreich’s Ataxia

Tucson, AZ, and Downingtown, PA — Dec. 4, 2017 — Critical Path Institute's (C-Path) Data Collaboration Center (DCC) and the Friedreich's Ataxia Research Alliance (FARA) have announced that they will work together to develop an aggregated database of clinical data for Friedreich's ataxia (FA). Use of this database will promote collaborative research to support the understanding of natural history, potential biomarkers, and potential clinical endpoints for patients with FA, which will help researchers develop more efficient clinical trial protocols to test new therapies more quickly and effectively.

The project will establish an integrated database of clinical data for FA that can be shared and utilized by existing FA researchers. It will enlist companies that have carried out clinical trials in FA to obtain contributions of clinical data, as well as sharing natural history data collected by FARA's collaborative clinical research network.

The role of oxidative stress in Friedreich's ataxia

Federica Lupoli, Tommaso Vannocci, Giovanni Longo, Neri Niccolai and Annalisa Pastore. FEBS Letters, DOI: 10.1002/1873-3468.12928

Friedreich's ataxia is an excellent paradigmatic example of a disease in which oxidative stress plays an important, albeit not completely understood, role. Friedreich's ataxia is a rare genetic neurodegenerative disease which involves partial silencing of frataxin, a small mitochondrial protein completely ignored before being linked to Friedreich's ataxia.

Peripheral nerve ultrasound in Friedreich ataxia

Mulroy, E., Pelosi, L., Leadbetter, R., Joshi, P., Rodrigues, M., Mossman, S., Kilfoyle, D. and Roxburgh, R. (2017). Muscle Nerve. doi: 10.1002/mus.26012

The nerves of the patients with FRDA were significantly larger than those of healthy controls at all upper limb sites (P < 0.05) but not significantly different in the lower limbs.
Our findings add additional weight to the theory that dorsal root ganglionopathy is not the sole cause of peripheral sensory loss in FRDA. Peripheral neuropathic processes are also likely to play a role.