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Browsing by Author "Scaglia, Fernando"
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Item Biallelic variants in COX4I1 associated with a novel phenotype resembling Leigh syndrome with developmental regression, intellectual disability, and seizures(Wiley, 2019-10) Pillai, Nishitha R.; AlDhaheri, Noura S.; Gosh, Rajashri; Lim, Jaehyung; Streff, Haley; Nayak, Anuranjita; Graham, Brett H.; Hanchard, Neil; Elsea, Sarah H.; Scaglia, Fernando; Medical and Molecular Genetics, School of MedicineAutosomal recessive COX4I1 deficiency has been previously reported in a single individual with a homozygous pathogenic variant in COX4I1, who presented with short stature, poor weight gain, dysmorphic features, and features of Fanconi anemia. COX4I1 encodes subunit 4, isoform 1 of cytochrome c oxidase. Cytochrome c oxidase is a respiratory chain enzyme that plays an important role in mitochondrial electron transport and reduces molecular oxygen to water leading to the formation of ATP. Defective production of cytochrome c oxidase leads to a variable phenotypic spectrum ranging from isolated myopathy to Leigh syndrome. Here, we describe two siblings, born to consanguineous parents, who presented with encephalopathy, developmental regression, hypotonia, pathognomonic brain imaging findings resembling Leigh‐syndrome, and a novel homozygous variant on COX4I1, expanding the known clinical phenotype associated with pathogenic variants in COX4I1.Item Lessons learned from additional research analyses of unsolved clinical exome cases(BioMed Central, 2017-03-21) Eldomery, Mohammad K.; Coban-Akdemir, Zeynep; Harel, Tamar; Rosenfeld, Jill A.; Gambin, Tomasz; Stray-Pedersen, Asbjørg; Küry, Sébastien; Mercier, Sandra; Lessel, Davor; Denecke, Jonas; Wiszniewski, Wojciech; Penney, Samantha; Liu, Pengfei; Bi, Weimin; Lalani, Seema R.; Schaaf, Christian P.; Wangler, Michael F.; Bacino, Carlos A.; Lewis, Richard Alan; Potocki, Lorraine; Graham, Brett H.; Belmont, John W.; Scaglia, Fernando; Orange, Jordan S.; Jhangiani, Shalini N.; Chiang, Theodore; Doddapaneni, Harsha; Hu, Jianhong; Muzny, Donna M.; Xia, Fan; Beaudet, Arthur L.; Boerwinkle, Eric; Eng, Christine M.; Plon, Sharon E.; Sutton, V. Reid; Gibbs, Richard A.; Posey, Jennifer E.; Yang, Yaping; Lupski, James R.; Department of Pathology and Laboratory Medicine, IU School of MedicineBACKGROUND: Given the rarity of most single-gene Mendelian disorders, concerted efforts of data exchange between clinical and scientific communities are critical to optimize molecular diagnosis and novel disease gene discovery. METHODS: We designed and implemented protocols for the study of cases for which a plausible molecular diagnosis was not achieved in a clinical genomics diagnostic laboratory (i.e. unsolved clinical exomes). Such cases were recruited to a research laboratory for further analyses, in order to potentially: (1) accelerate novel disease gene discovery; (2) increase the molecular diagnostic yield of whole exome sequencing (WES); and (3) gain insight into the genetic mechanisms of disease. Pilot project data included 74 families, consisting mostly of parent-offspring trios. Analyses performed on a research basis employed both WES from additional family members and complementary bioinformatics approaches and protocols. RESULTS: Analysis of all possible modes of Mendelian inheritance, focusing on both single nucleotide variants (SNV) and copy number variant (CNV) alleles, yielded a likely contributory variant in 36% (27/74) of cases. If one includes candidate genes with variants identified within a single family, a potential contributory variant was identified in a total of ~51% (38/74) of cases enrolled in this pilot study. The molecular diagnosis was achieved in 30/63 trios (47.6%). Besides this, the analysis workflow yielded evidence for pathogenic variants in disease-associated genes in 4/6 singleton cases (66.6%), 1/1 multiplex family involving three affected siblings, and 3/4 (75%) quartet families. Both the analytical pipeline and the collaborative efforts between the diagnostic and research laboratories provided insights that allowed recent disease gene discoveries (PURA, TANGO2, EMC1, GNB5, ATAD3A, and MIPEP) and increased the number of novel genes, defined in this study as genes identified in more than one family (DHX30 and EBF3). CONCLUSION: An efficient genomics pipeline in which clinical sequencing in a diagnostic laboratory is followed by the detailed reanalysis of unsolved cases in a research environment, supplemented with WES data from additional family members, and subject to adjuvant bioinformatics analyses including relaxed variant filtering parameters in informatics pipelines, can enhance the molecular diagnostic yield and provide mechanistic insights into Mendelian disorders. Implementing these approaches requires collaborative clinical molecular diagnostic and research efforts.Item Phenotypic expansion in DDX3X - a common cause of intellectual disability in females(Wiley, 2018-09-15) Wang, Xia; Posey, Jennifer E.; Rosenfeld, Jill A.; Bacino, Carlos A.; Scaglia, Fernando; Immken, LaDonna; Harris, Jill M.; Hickey, Scott E.; Mosher, Theresa M.; Slavotinek, Anne; Zhang, Jing; Beuten, Joke; Leduc, Magalie S.; He, Weimin; Vetrini, Francesco; Walkiewicz, Magdalena A.; Bi, Weimin; Xiao, Rui; Liu, Pengfei; Shao, Yunru; Gezdirici, Alper; Gulec, Elif Y.; Jiang, Yunyun; Darilek, Sandra A.; Hansen, Adam W.; Khayat, Michael M.; Pehlivan, Davut; Piard, Juliette; Muzny, Donna M.; Hanchard, Neil; Belmont, John W.; Van Maldergem, Lionel; Gibbs, Richard A.; Eldomery, Mohammad K.; Akdemir, Zeynep C.; Adesina, Adekunle M.; Chen, Shan; Lee, Yi-Chien; Lee, Brendan; Lupski, James R.; Eng, Christine M.; Xia, Fan; Yang, Yaping; Graham, Brett H.; Moretti, Paolo; Medical and Molecular Genetics, School of MedicineDe novo variants in DDX3X account for 1-3% of unexplained intellectual disability (ID) cases and are amongst the most common causes of ID especially in females. Forty-seven patients (44 females, 3 males) have been described. We identified 31 additional individuals carrying 29 unique DDX3X variants, including 30 postnatal individuals with complex clinical presentations of developmental delay or ID, and one fetus with abnormal ultrasound findings. Rare or novel phenotypes observed include respiratory problems, congenital heart disease, skeletal muscle mitochondrial DNA depletion, and late-onset neurologic decline. Our findings expand the spectrum of DNA variants and phenotypes associated with DDX3X disorders.