@article {810, title = {Missed diagnoses: Clinically relevant lessons learned through medical mysteries solved by the Undiagnosed Diseases Network.}, journal = {Mol Genet Genomic Med}, volume = {8}, year = {2020}, month = {2020 10}, pages = {e1397}, abstract = {

BACKGROUND: Resources within the Undiagnosed Diseases Network (UDN), such as genome sequencing (GS) and model organisms aid in diagnosis and identification of new disease genes, but are currently difficult to access by clinical providers. While these resources do contribute to diagnoses in many cases, they are not always necessary to reach diagnostic resolution. The UDN experience has been that participants can also receive diagnoses through the thoughtful and customized application of approaches and resources that are readily available in clinical settings.

METHODS: The UDN Genetic Counseling and Testing Working Group collected case vignettes that illustrated how clinically available methods resulted in diagnoses. The case vignettes were classified into three themes; phenotypic considerations, selection of genetic testing, and evaluating exome/GS variants and data.

RESULTS: We present 12 participants that illustrate how clinical practices such as phenotype-driven genomic investigations, consideration of variable expressivity, selecting the relevant tissue of interest for testing, utilizing updated testing platforms, and recognition of alternate transcript nomenclature resulted in diagnoses.

CONCLUSION: These examples demonstrate that when a diagnosis is elusive, an iterative patient-specific approach utilizing assessment options available to clinical providers may solve a portion of cases. However, this does require increased provider time commitment, a particular challenge in the current practice of genomics.

}, keywords = {Adolescent, Child, Child, Preschool, Databases, Factual, Diagnosis, Computer-Assisted, Female, Genetic Diseases, Inborn, Genetic Testing, Humans, Information Dissemination, Male, Middle Aged, Missed Diagnosis, National Institutes of Health (U.S.), Phenotype, Precision Medicine, Undiagnosed Diseases, United States, Young Adult}, issn = {2324-9269}, doi = {10.1002/mgg3.1397}, author = {Cope, Heidi and Spillmann, Rebecca and Rosenfeld, Jill A and Brokamp, Elly and Signer, Rebecca and Schoch, Kelly and Kelley, Emily G and Sullivan, Jennifer A and Macnamara, Ellen and Lincoln, Sharyn and Golden-Grant, Katie and Orengo, James P and Clark, Gary and Burrage, Lindsay C and Posey, Jennifer E and Punetha, Jaya and Robertson, Amy and Cogan, Joy and Phillips, John A and Martinez-Agosto, Julian and Shashi, Vandana} } @article {90, title = {Recurrent Muscle Weakness with Rhabdomyolysis, Metabolic Crises, and Cardiac Arrhythmia Due to Bi-allelic TANGO2 Mutations.}, journal = {Am J Hum Genet}, volume = {98}, year = {2016}, month = {2016 Feb 04}, pages = {347-57}, abstract = {

The underlying genetic etiology of rhabdomyolysis remains elusive in a significant fraction of individuals presenting with recurrent metabolic crises and muscle weakness. Using exome sequencing, we identified bi-allelic mutations in TANGO2 encoding transport and Golgi organization 2 homolog (Drosophila) in 12 subjects with episodic rhabdomyolysis, hypoglycemia, hyperammonemia, and susceptibility to life-threatening cardiac tachyarrhythmias. A recurrent homozygous c.460G>A (p.Gly154Arg) mutation was found in four unrelated individuals of Hispanic/Latino origin, and a homozygous \~{}34 kb deletion affecting exons 3-9 was observed in two families of European ancestry. One individual of mixed Hispanic/European descent was found to be compound heterozygous for c.460G>A (p.Gly154Arg) and the deletion of exons 3-9. Additionally, a homozygous exons 4-6 deletion was identified in a consanguineous Middle Eastern Arab family. No homozygotes have been reported for these changes in control databases. Fibroblasts derived from a subject with the recurrent c.460G>A (p.Gly154Arg) mutation showed evidence of increased endoplasmic reticulum stress and a reduction in Golgi volume density in comparison to control. Our results show that the c.460G>A (p.Gly154Arg) mutation and the exons 3-9 heterozygous deletion in TANGO2 are recurrent pathogenic alleles present in the Latino/Hispanic and European populations, respectively, causing considerable morbidity in the homozygotes in these populations.

}, keywords = {Alleles, Arabs, Arrhythmias, Cardiac, Base Sequence, Child, Child, Preschool, Endoplasmic Reticulum Stress, European Continental Ancestry Group, Exome, Exons, Female, Gene Deletion, Golgi Apparatus, Hispanic Americans, Homozygote, Humans, Infant, Male, Molecular Sequence Data, Muscle Weakness, Pedigree, Rhabdomyolysis}, issn = {1537-6605}, doi = {10.1016/j.ajhg.2015.12.008}, author = {Lalani, Seema R and Liu, Pengfei and Rosenfeld, Jill A and Watkin, Levi B and Chiang, Theodore and Leduc, Magalie S and Zhu, Wenmiao and Ding, Yan and Pan, Shujuan and Vetrini, Francesco and Miyake, Christina Y and Shinawi, Marwan and Gambin, Tomasz and Eldomery, Mohammad K and Akdemir, Zeynep Hande Coban and Emrick, Lisa and Wilnai, Yael and Schelley, Susan and Koenig, Mary Kay and Memon, Nada and Farach, Laura S and Coe, Bradley P and Azamian, Mahshid and Hernandez, Patricia and Zapata, Gladys and Jhangiani, Shalini N and Muzny, Donna M and Lotze, Timothy and Clark, Gary and Wilfong, Angus and Northrup, Hope and Adesina, Adekunle and Bacino, Carlos A and Scaglia, Fernando and Bonnen, Penelope E and Crosson, Jane and Duis, Jessica and Maegawa, Gustavo H B and Coman, David and Inwood, Anita and McGill, Jim and Boerwinkle, Eric and Graham, Brett and Beaudet, Art and Eng, Christine M and Hanchard, Neil A and Xia, Fan and Orange, Jordan S and Gibbs, Richard A and Lupski, James R and Yang, Yaping} }