Browsing by Subject "Rare disease"
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Item Burosumab vs conventional therapy in children with X-linked hypophosphatemia: results of the open-label, phase 3 extension period(Oxford University Press, 2024-01-04) Ward, Leanne M.; Högler, Wolfgang; Glorieux, Francis H.; Portale, Anthony A.; Whyte, Michael P.; Munns, Craig F.; Nilsson, Ola; Simmons, Jill H.; Padidela, Raja; Namba, Noriyuki; Cheong, Hae, Il; Sochett, Etienne; Muroya, Koji; Tanaka, Hiroyuki; Pitukcheewanont, Pisit; Gottesman, Gary S.; Biggin, Andrew; Perwad, Farzana; Chen, Angel; Merritt, John Lawrence, II; Imel, Erik A.; Medicine, School of MedicineIn a randomized, open-label phase 3 study of 61 children aged 1-12 years old with X-linked hypophosphatemia (XLH) previously treated with conventional therapy, changing to burosumab every 2 weeks (Q2W) for 64 weeks improved the phosphate metabolism, radiographic rickets, and growth compared with conventional therapy. In this open-label extension period (weeks 64-88), 21 children continued burosumab Q2W at the previous dose or crossed over from conventional therapy to burosumab starting at 0.8 mg/kg Q2W with continued clinical radiographic assessments through week 88. Efficacy endpoints and safety observations were summarized descriptively for both groups (burosumab continuation, n = 6; crossover, n = 15). At week 88 compared with baseline, improvements in the following outcomes were observed in the burosumab continuation and crossover groups, respectively: mean (SD) RGI-C rickets total score (primary outcome), +2.11 (0.27) and +1.89 (0.35); mean (SD) RGI-C lower limb deformity score, +1.61 (0.91) and +0.73 (0.82); and mean (SD) height Z-score + 0.41 (0.50) and +0.08 (0.34). Phosphate metabolism normalized rapidly in the crossover group and persisted in the continuation group. Mean (SD) serum alkaline phosphatase decreased from 169% (43%) of the upper limit of normal (ULN) at baseline to 126% (51%) at week 88 in the continuation group and from 157% (33%) of the ULN at baseline to 111% (23%) at week 88 in the crossover group. During the extension period, treatment-emergent adverse events (AEs) were reported in all 6 children in the burosumab continuation group and 14/15 children in the crossover group. The AE profiles in the randomized and extension periods were similar, with no new safety signals identified. Improvements from baseline in radiographic rickets continued in the extension period among children with XLH who remained on burosumab. Children who crossed over from conventional therapy to burosumab demonstrated a rapid improvement in phosphate metabolism and improved rickets healing over the ensuing 22 weeks.Item Consensus clinical management guidelines for Alström syndrome(BMC, 2020-09-21) Tahani, Natascia; Maffei, Pietro; Dollfus, Hélène; Paisey, Richard; Valverde, Diana; Milan, Gabriella; Han, Joan C.; Favaretto, Francesca; Madathil, Shyam C.; Dawson, Charlotte; Armstrong, Matthew J.; Warfield, Adrian T.; Düzenli, Selma; Francomano, Clair A.; Gunay-Aygun, Meral; Dassie, Francesca; Marion, Vincent; Valenti, Marina; Leeson-Beevers, Kerry; Chivers, Ann; Steeds, Richard; Barrett, Timothy; Geberhiwot, Tarekegn; Medical and Molecular Genetics, School of MedicineAlström Syndrome (ALMS) is an ultra-rare multisystem genetic disorder caused by autosomal recessive variants in the ALMS1 gene, which is located on chromosome 2p13. ALMS is a multisystem, progressive disease characterised by visual disturbance, hearing impairment, cardiomyopathy, childhood obesity, extreme insulin resistance, accelerated non-alcoholic fatty liver disease (NAFLD), renal dysfunction, respiratory disease, endocrine and urologic disorders. Clinical symptoms first appear in infancy with great variability in age of onset and severity. ALMS has an estimated incidence of 1 case per 1,000,000 live births and ethnically or geographically isolated populations have a higher-than-average frequency. The rarity and complexity of the syndrome and the lack of expertise can lead to delayed diagnosis, misdiagnosis and inadequate care. Multidisciplinary and multiprofessional teams of experts are essential for the management of patients with ALMS, as early diagnosis and intervention can slow the progression of multi-organ dysfunctions and improve patient quality of life. These guidelines are intended to define standard of care for patients suspected or diagnosed with ALMS of any age. All information contained in this document has originated from a systematic review of the literature and the experiences of the authors in their care of patients with ALMS. The Appraisal of Guidelines for Research & Evaluation (AGREE II) system was adopted for the development of the guidelines and for defining the related levels of evidence and strengths of recommendations. These guidelines are addressed to: a) specialist centres, other hospital-based medical teams and staffs involved with the care of ALMS patients, b) family physicians and other primary caregivers and c) patients and their families.Item Deoxyhypusine synthase mutations alter the post-translational modification of eukaryotic initiation factor 5A resulting in impaired human and mouse neural homeostasis(Elsevier, 2023-05-18) Padgett, Leah R.; Shinkle, Mollie R.; Rosario, Spencer; Murray Stewart, Tracy; Foley, Jackson R.; Casero, Robert A.. Jr.; Park, Myung Hee; Chung, Wendy K.; Mastracci, Teresa L.; Biology, School of ScienceDHPS deficiency is a rare genetic disease caused by biallelic hypomorphic variants in the Deoxyhypusine synthase (DHPS) gene. The DHPS enzyme functions in mRNA translation by catalyzing the post-translational modification, and therefore activation, of eukaryotic initiation factor 5A (eIF5A). The observed clinical outcomes associated with human mutations in DHPS include developmental delay, intellectual disability, and seizures. Therefore, to increase our understanding of this rare disease, it is critical to determine the mechanisms by which mutations in DHPS alter neurodevelopment. In this study, we have generated patient-derived lymphoblast cell lines and demonstrated that human DHPS variants alter DHPS protein abundance and impair enzyme function. Moreover, we observe a shift in the abundance of the post-translationally modified forms of eIF5A; specifically, an increase in the nuclear localized acetylated form (eIF5AAcK47) and concomitant decrease in the cytoplasmic localized hypusinated form (eIF5AHYP). Generation and characterization of a mouse model with a genetic deletion of Dhps in the brain at birth shows that loss of hypusine biosynthesis impacts neuronal function due to impaired eIF5AHYP-dependent mRNA translation; this translation defect results in altered expression of proteins required for proper neuronal development and function. This study reveals new insight into the biological consequences and molecular impact of human DHPS deficiency and provides valuable information toward the goal of developing treatment strategies for this rare disease.Item Deoxyhypusine synthase mutations alter the post-translational modification of eukaryotic initiation factor 5A resulting in impaired human and mouse neural homeostasis(Elsevier, 2023-05-18) Padgett, Leah R.; Shinkle, Mollie R.; Rosario, Spencer; Murray Stewart, Tracy; Foley, Jackson R.; Casero, Robert A., Jr.; Park, Myung Hee; Chung, Wendy K.; Mastracci, Teresa L.; Biology, School of ScienceDHPS deficiency is a rare genetic disease caused by biallelic hypomorphic variants in the Deoxyhypusine synthase (DHPS) gene. The DHPS enzyme functions in mRNA translation by catalyzing the post-translational modification, and therefore activation, of eukaryotic initiation factor 5A (eIF5A). The observed clinical outcomes associated with human mutations in DHPS include developmental delay, intellectual disability, and seizures. Therefore, to increase our understanding of this rare disease, it is critical to determine the mechanisms by which mutations in DHPS alter neurodevelopment. In this study, we have generated patient-derived lymphoblast cell lines and demonstrated that human DHPS variants alter DHPS protein abundance and impair enzyme function. Moreover, we observe a shift in the abundance of the post-translationally modified forms of eIF5A; specifically, an increase in the nuclear localized acetylated form (eIF5AAcK47) and concomitant decrease in the cytoplasmic localized hypusinated form (eIF5AHYP). Generation and characterization of a mouse model with a genetic deletion of Dhps in the brain at birth shows that loss of hypusine biosynthesis impacts neuronal function due to impaired eIF5AHYP-dependent mRNA translation; this translation defect results in altered expression of proteins required for proper neuronal development and function. This study reveals new insight into the biological consequences and molecular impact of human DHPS deficiency and provides valuable information toward the goal of developing treatment strategies for this rare disease.Item Improving Social Media-Based Support Groups for the Rare Disease Community: Interview Study With Patients and Parents of Children with Rare and Undiagnosed Diseases(JMIR, 2024-12-30) Doyle, Tom A.; Vershaw, Samantha L.; Conboy, Erin; Halverson, Colin M. E.; Medical and Molecular Genetics, School of MedicineBackground: The rarity that is inherent in rare disease (RD) often means that patients and parents of children with RDs feel uniquely isolated and therefore are unprepared or unsupported in their care. To overcome this isolation, many within the RD community turn to the internet, and social media groups in particular, to gather useful information about their RDs. While previous research has shown that social media support groups are helpful for those affected by RDs, it is unclear what these groups are particularly useful or helpful for patients and parents of children with RDs. Objective: This study aimed to identify what specific features of disease-related support groups (DRSGs) the RD community finds particularly useful or supportive and provide a set of recommendations to improve social media-based RD support groups based on this information. Methods: Semistructured qualitative interviews were performed with patients and parents of patients with RDs. Interview participants had to be at least 18 years of age at the time of the interview, be seen by a genetics specialist at a partner health care institution and be proficient in the English language. Social media use was not a prerequisite for participation, so interview participants ranged from extensive users of social media to those who chose to remain off all social media. All interviews were conducted by phone, recorded, and then transcribed. Interview transcripts were then coded using the 6 steps outlined by Braun and Clarke. Three researchers (TAD, SLV, and CMEH) performed initial coding. After this, the study team conducted a review of themes and all members of the team agreed upon a final analysis and presentation of data. Results: We conducted 31 interviews (mean age 40, SD 10.04 years; n=27, 87% were women; n=30, 97% were non-Hispanic White). Thematic analysis revealed that social media DRSG users identified the informational usefulness of these groups as being related to the gathering and sharing of specific information about an RD, clarification about the importance and meaning of certain symptoms, and obtaining insight into an RD's progression and prognosis. Participants also identified that DRSGs were useful sources of practical information, such as tips and tricks about managing RD-related issues and concerns. In addition, participants found DRSGs to be a useful space for sharing their disease-related stories but also highlighted a feeling of exhaustion from overexposure and overuse of DRSGs. Conclusions: This study identifies the usefulness of DRSGs for the RD community and provides a set of recommendations to improve future instances of DRSGs. These recommendations can be used to create DRSGs that are less prone to splintering into other DRSGs, thus minimizing the risk of having important RD-related information unhelpfully dispersed amongst a multitude of support groups.Item Linguistic, Content and Face Validity of the Swedish Version of a Quality-of-Life Assessment for Children, Teenagers and Adults with Spina Bifida(MDPI, 2024-05-15) Dellenmark-Blom, Michaela; Andersson, Marie; Szymanski, Konrad M.; Andréasson, Charlotta Levén; Arnell, Magdalena Vu Minh; Sjöström, Sofia; Abrahamsson, Kate; Pediatrics, School of MedicineSpina bifida includes a spectrum of different neural tube defects. Myelomeningocele is the most serious type and is associated with a risk of paralysis and sensory dysfunction below the affected level, bladder/bowel dysfunction, brain dysmorphology, and impaired health-related quality of life (HRQoL). The aim of this study was to describe the establishment of linguistic, content and face validity of the Swedish version of a Quality-of-Life Assessment for children (QUALAS-C, n = 10 items), teenagers (QUALAS-T, n = 10 items) and adults with spina bifida (QUALAS-A, n = 15 items) based on the original US English versions. The process included close collaboration with the original instrument developer and complied with international standards on patient-reported outcome measurements. The procedure includes forward translation, expert and patient/parent review and reconciliation, back translation, back translation review and cognitive debriefing interviews with 16 people with spina bifida aged 8 to 33, providing them with the possibility of evaluating the clarity, adequacy, and comprehensiveness of QUALAS-C, QUALAS-T and QUALAS-A, respectively. The interviews lasted a median of 15 min (range 8–16) for QUALAS-C, 10 min (range 9–15) for QUALAS-T and 24 min (range 9–38) for QUALAS-A. Four main issues/topics needed attention and discussion after both the forward and back translation. Following the back translation review, all issues were resolved. The patient feedback revealed recognition of the HRQoL issues included in QUALAS, and also difficulties in understanding some questions. After the patients’ evaluation, four items were reworded for clarity. No study participant reported a wish to add to or remove questions from QUALAS. Hence, the Swedish versions of QUALAS became conceptually equivalent to the original US English versions and achieved linguistic, content and face validity. While empowering the voices of people with spina bifida, these results also enable their HRQoL to be properly assessed in research and clinical care in Sweden and in international studies.Item Loss-of-function OGFRL1 variants identified in autosomal recessive cherubism families(Oxford University Press, 2024-04-09) Kittaka, Mizuho; Mizuno, Noriyoshi; Morino, Hiroyuki; Yoshimoto, Tetsuya; Zhu, Tianli; Liu, Sheng; Wang, Ziyi; Mayahara, Kotoe; Iio, Kyohei; Kondo, Kaori; Kondo, Toshio; Hayashi, Tatsuhide; Coghlan, Sarah; Teno, Yayoi; Doan, Andrew Anh Phung; Levitan, Marcus; Choi, Roy B.; Matsuda, Shinji; Ouhara, Kazuhisa; Wan, Jun; Cassidy, Annelise M.; Pelletier, Stephane; Nampoothiri, Sheela; Urtizberea, Andoni J.; Robling, Alexander G.; Ono, Mitsuaki; Kawakami, Hideshi; Reichenberger, Ernst J.; Ueki, Yasuyoshi; Anatomy, Cell Biology and Physiology, School of MedicineCherubism (OMIM 118400) is a rare craniofacial disorder in children characterized by destructive jawbone expansion due to the growth of inflammatory fibrous lesions. Our previous studies have shown that gain-of-function mutations in SH3 domain-binding protein 2 (SH3BP2) are responsible for cherubism and that a knock-in mouse model for cherubism recapitulates the features of cherubism, such as increased osteoclast formation and jawbone destruction. To date, SH3BP2 is the only gene identified to be responsible for cherubism. Since not all patients clinically diagnosed with cherubism had mutations in SH3BP2, we hypothesized that there may be novel cherubism genes and that these genes may play a role in jawbone homeostasis. Here, using whole exome sequencing, we identified homozygous loss-of-function variants in the opioid growth factor receptor like 1 (OGFRL1) gene in 2 independent autosomal recessive cherubism families from Syria and India. The newly identified pathogenic homozygous variants were not reported in any variant databases, suggesting that OGFRL1 is a novel gene responsible for cherubism. Single cell analysis of mouse jawbone tissue revealed that Ogfrl1 is highly expressed in myeloid lineage cells. We generated OGFRL1 knockout mice and mice carrying the Syrian frameshift mutation to understand the in vivo role of OGFRL1. However, neither mouse model recapitulated human cherubism or the phenotypes exhibited by SH3BP2 cherubism mice under physiological and periodontitis conditions. Unlike bone marrow-derived M-CSF-dependent macrophages (BMMs) carrying the SH3BP2 cherubism mutation, BMMs lacking OGFRL1 or carrying the Syrian mutation showed no difference in TNF-ɑ mRNA induction by LPS or TNF-ɑ compared to WT BMMs. Osteoclast formation induced by RANKL was also comparable. These results suggest that the loss-of-function effects of OGFRL1 in humans differ from those in mice and highlight the fact that mice are not always an ideal model for studying rare craniofacial bone disordersItem The impact of clinical genome sequencing in a global population with suspected rare genetic disease(Elsevier, 2024) Thorpe, Erin; Williams, Taylor; Shaw, Chad; Chekalin, Evgenii; Ortega, Julia; Robinson, Keisha; Button, Jason; Jones, Marilyn C.; Del Campo, Miguel; Basel, Donald; McCarrier, Julie; Davis Keppen, Laura; Royer, Erin; Foster-Bonds, Romina; Duenas-Roque, Milagros M.; Urraca, Nora; Bosfield, Kerri; Brown, Chester W.; Lydigsen, Holly; Mroczkowski, Henry J.; Ward, Jewell; Sirchia, Fabio; Giorgio, Elisa; Vaux, Keith; Peña Salguero, Hildegard; Lumaka, Aimé; Mubungu, Gerrye; Makay, Prince; Ngole, Mamy; Tshilobo Lukusa, Prosper; Vanderver, Adeline; Muirhead, Kayla; Sherbini, Omar; Lah, Melissa D.; Anderson, Katelynn; Bazalar-Montoya, Jeny; Rodriguez, Richard S.; Cornejo-Olivas, Mario; Milla-Neyra, Karina; Shinaw, Marwan; Magoulas, Pilar; Henry, Duncan; Gibson, Kate; Wiaf, Samuel; Jayakar, Parul; Salyakina, Daria; Masser-Frye, Diane; Serize, Arturo; Perez, Jorge E.; Taylor, Alan; Shenbagam, Shruti; Tayoun, Ahmad Abou; Malhotra, Alka; Bennett, Maren; Rajan, Vani; Avecilla, James; Warren, Andrew; Arseneault, Max; Kalista, Tasha; Crawford, Ali; Ajay, Subramanian S.; Perry, Denise L.; Belmont, John; Taft, Ryan J.; Medicine, School of MedicineThere is mounting evidence of the value of clinical genome sequencing (cGS) in individuals with suspected rare genetic disease (RGD), but cGS performance and impact on clinical care in a diverse population drawn from both high-income countries (HICs) and low- and middle-income countries (LMICs) has not been investigated. The iHope program, a philanthropic cGS initiative, established a network of 24 clinical sites in eight countries through which it provided cGS to individuals with signs or symptoms of an RGD and constrained access to molecular testing. A total of 1,004 individuals (median age, 6.5 years; 53.5% male) with diverse ancestral backgrounds (51.8% non-majority European) were assessed from June 2016 to September 2021. The diagnostic yield of cGS was 41.4% (416/1,004), with individuals from LMIC sites 1.7 times more likely to receive a positive test result compared to HIC sites (LMIC 56.5% [195/345] vs. HIC 33.5% [221/659], OR 2.6, 95% CI 1.9-3.4, p < 0.0001). A change in diagnostic evaluation occurred in 76.9% (514/668) of individuals. Change of management, inclusive of specialty referrals, imaging and testing, therapeutic interventions, and palliative care, was reported in 41.4% (285/694) of individuals, which increased to 69.2% (480/694) when genetic counseling and avoidance of additional testing were also included. Individuals from LMIC sites were as likely as their HIC counterparts to experience a change in diagnostic evaluation (OR 6.1, 95% CI 1.1-∞, p = 0.05) and change of management (OR 0.9, 95% CI 0.5-1.3, p = 0.49). Increased access to genomic testing may support diagnostic equity and the reduction of global health care disparities.Item TNPO2 variants associate with human developmental delays, neurologic deficits, and dysmorphic features and alter TNPO2 activity in Drosophila(Elsevier, 2021) Goodman, Lindsey D.; Cope, Heidi; Nil, Zelha; Ravenscroft, Thomas A.; Charng, Wu-Lin; Lu, Shenzhao; Tien, An-Chi; Pfundt, Rolph; Koolen, David A.; Haaxma, Charlotte A.; Veenstra-Knol, Hermine E.; Klein Wassink-Ruiter, Jolien S.; Wevers, Marijke R.; Jones, Melissa; Walsh, Laurence E.; Klee, Victoria H.; Theunis, Miel; Legius, Eric; Steel, Dora; Barwick, Katy E.S.; Kurian, Manju A.; Mohammad, Shekeeb. S.; Dale, Russell C.; Terhal, Paulien A.; van Binsbergen, Ellen; Kirmse, Brian; Robinette, Bethany; Cogné, Benjamin; Isidor, Bertrand; Grebe, Theresa A.; Kulch, Peggy; Hainline, Bryan E.; Sapp, Katherine; Morava, Eva; Klee, Eric W.; Macke, Erica L.; Trapane, Pamela; Spencer, Christopher; Si, Yue; Begtrup, Amber; Moulton, Matthew J.; Dutta, Debdeep; Kanca, Oguz; Undiagnosed Diseases Network; Wangler, Michael F.; Yamamoto, Shinya; Bellen, Hugo J.; Tan, Queenie K.G.; Pediatrics, School of MedicineTransportin-2 (TNPO2) mediates multiple pathways including non-classical nucleocytoplasmic shuttling of >60 cargoes, such as developmental and neuronal proteins. We identified 15 individuals carrying de novo coding variants in TNPO2 who presented with global developmental delay (GDD), dysmorphic features, ophthalmologic abnormalities, and neurological features. To assess the nature of these variants, functional studies were performed in Drosophila. We found that fly dTnpo (orthologous to TNPO2) is expressed in a subset of neurons. dTnpo is critical for neuronal maintenance and function as downregulating dTnpo in mature neurons using RNAi disrupts neuronal activity and survival. Altering the activity and expression of dTnpo using mutant alleles or RNAi causes developmental defects, including eye and wing deformities and lethality. These effects are dosage dependent as more severe phenotypes are associated with stronger dTnpo loss. Interestingly, similar phenotypes are observed with dTnpo upregulation and ectopic expression of TNPO2, showing that loss and gain of Transportin activity causes developmental defects. Further, proband-associated variants can cause more or less severe developmental abnormalities compared to wild-type TNPO2 when ectopically expressed. The impact of the variants tested seems to correlate with their position within the protein. Specifically, those that fall within the RAN binding domain cause more severe toxicity and those in the acidic loop are less toxic. Variants within the cargo binding domain show tissue-dependent effects. In summary, dTnpo is an essential gene in flies during development and in neurons. Further, proband-associated de novo variants within TNPO2 disrupt the function of the encoded protein. Hence, TNPO2 variants are causative for neurodevelopmental abnormalities.