The Genomic landscape of short tandem repeats across multiple ancestries
Vijayaraghavan P, Batalov S, Ding Y, Sanford E, Kingsmore SF, Dimmock D, Hobbs C, Bainbridge M.
PLoS One. 2023 Jan 26;18(1):e0279430. doi: 10.1371/journal.pone.0279430. eCollection 2023.
ABSTRACT
Short Tandem Repeats (STRs) have been found to play a role in a myriad of complex traits and genetic diseases. We examined the variability in the lengths of over 850,000 STR loci in 996 children with suspected genetic disorders and 1,178 parents across six separate ancestral groups: Africans, Europeans, East Asians, Admixed Americans, Non-admixed Americans, and Pacific Islanders. For each STR locus we compared allele length between and within each ancestry group. In relation to Europeans, admixed Americans had the most similar STR lengths with only 623 positions either significantly expanded or contracted, while the divergence was highest in Africans, with 4,933 chromosomal positions contracted or expanded. We also examined probands to identify STR expansions at known pathogenic loci. The genes TCF4, AR, and DMPK showed significant expansions with lengths 250% greater than their various average allele lengths in 49, 162, and 11 individuals respectively. All 49 individuals containing an expansion in TCF4 and six individuals containing an expansion in DMPK presented with allele lengths longer than the known pathogenic length for these genes. Next, we identified individuals with significant expansions in highly conserved loci across all ancestries. Eighty loci in conserved regions met criteria for divergence. Two of these individuals were found to have exonic STR expansions: one in ZBTB4 and the other in SLC9A7, which is associated with X-linked mental retardation. Finally, we used parent-child trios to detect and analyze de novo mutations. In total, we observed 3,219 de novo expansions, where proband allele lengths are greater than twice the longest parental allele length. This work helps lay the foundation for understanding STR lengths genome-wide across ancestries and may help identify new disease genes and novel mechanisms of pathogenicity in known disease genes.
PMID:
36701310 DOI:
10.1371/journal.pone.0279430
January 26, 2023
Gene DiscoveryRare Disease
Are we prepared to deliver gene-targeted therapies for rare diseases?
Yu TW, Kingsmore SF, Green RC, MacKenzie T, Wasserstein M, Caggana M, Gold NB, Kennedy A, Kishnani PS, Might M, Brooks PJ, Morris JA, Parisi MA, Urv TK.
Am J Med Genet C Semin Med Genet. 2023 Jan 24. doi: 10.1002/ajmg.c.32029. Online ahead of print.
ABSTRACT
The cost and time needed to conduct whole-genome sequencing (WGS) have decreased significantly in the last 20 years. At the same time, the number of conditions with a known molecular basis has steadily increased, as has the number of investigational new drug applications for novel gene-based therapeutics. The prospect of precision gene-targeted therapy for all seems in reach… or is it? Here we consider practical and strategic considerations that need to be addressed to establish a foundation for the early, effective, and equitable delivery of these treatments.
PMID:
36691939 DOI:
10.1002/ajmg.c.32029
January 24, 2023
Rare Disease
Insights into the perinatal phenotype of Kabuki syndrome in infants identified by genome-wide sequencing
Wigby K, Hammer M, Tokita M, Patel P, Jones MC, Larson A, Bartolomei FV, Dykzeul N, Slavotinek A, Yip T, Bandres-Ciga S, Simpson BN, Suhrie K, Shankar S, Veith R, Bragg J, Powell C, Kingsmore SF, Dimmock D, Maron J, Davis J, Del Campo M.
Am J Med Genet A. 2023 Jan 18. doi: 10.1002/ajmg.a.63097. Online ahead of print.
ABSTRACT
Increasing use of unbiased genomic sequencing in critically ill infants can expand understanding of rare diseases such as Kabuki syndrome (KS). Infants diagnosed with KS through genome-wide sequencing performed during the initial hospitalization underwent retrospective review of medical records. Human phenotype ontology terms used in genomic analysis were aggregated and analyzed. Clinicians were surveyed regarding changes in management and other care changes. Fifteen infants met inclusion criteria. KS was not suspected prior to genomic sequencing. Variants were classified as Pathogenic (n = 10) or Likely Pathogenic (n = 5) by American College of Medical Genetics and Genomics Guidelines. Fourteen variants were de novo (KMT2D, n = 12, KDM6A, n = 2). One infant inherited a likely pathogenic variant in KMT2D from an affected father. Frequent findings involved cardiovascular (14/15) and renal (7/15) systems, with palatal defects also identified (6/15). Three infants had non-immune hydrops. No minor anomalies were universally documented; ear anomalies, micrognathia, redundant nuchal skin, and hypoplastic nails were common. Changes in management were reported in 14 infants. Early use of unbiased genome-wide sequencing enabled a molecular diagnosis prior to clinical recognition including infants with atypical or rarely reported features of KS while also expanding the phenotypic spectrum of this rare disorder.
PMID:
36651673 DOI:
10.1002/ajmg.a.63097
January 18, 2023
Rare DiseaseRPM for NICU and PICU
An automated 13.5 hour system for scalable diagnosis and acute management guidance for genetic diseases
Mallory J. Owen, Sebastien Lefebvre, Christian Hansen, Chris M. Kunard, David P. Dimmock, Laurie D. Smith, Gunter Scharer, Rebecca Mardach, Mary J. Willis, Annette Feigenbaum, Anna-Kaisa Niemi, Yan Ding, Luca Van Der Kraan, Katarzyna Ellsworth, Lucia Guidugli, Bryan R. Lajoie, Timothy K. McPhail, Shyamal S. Mehtalia, Kevin K. Chau, Yong H. Kwon, Zhanyang Zhu, Sergey Batalov, Shimul Chowdhury, Seema Rego, James Perry, Mark Speziale, Mark Nespeca, Meredith S. Wright, Martin G. Reese, Francisco M. De La Vega, Joe Azure, Erwin Frise, Charlene Son Rigby, Sandy White, Charlotte A. Hobbs, Sheldon Gilmer, Gail Knight, Albert Oriol, Jerica Lenberg, Shareef A. Nahas, Kate Perofsky, Kyu Kim, Jeanne Carroll, Nicole G. Coufal, Erica Sanford, Kristen Wigby, Jacqueline Weir, Vicki S. Thomson, Louise Fraser, Seka S. Lazare, Yoon H. Shin, Haiying Grunenwald, Richard Lee, David Jones, Duke Tran, Andrew Gross, Patrick Daigle, Anne Case, Marisa Lue, James A. Richardson, John Reynders, Thomas Defay, Kevin P. Hall, Narayanan Veeraraghavan & Stephen F. Kingsmore
Nat Commun. 2022 Jul 26;13(1):4057. doi: 10.1038/s41467-022-31446-6.
While many genetic diseases have effective treatments, they frequently progress rapidly to severe morbidity or mortality if those treatments are not implemented immediately. Since front-line physicians frequently lack familiarity with these diseases, timely molecular diagnosis may not improve outcomes. Herein we describe Genome-to-Treatment, an automated, virtual system for genetic disease diagnosis and acute management guidance. Diagnosis is achieved in 13.5 h by expedited whole genome sequencing, with superior analytic performance for structural and copy number variants. An expert panel adjudicated the indications, contraindications, efficacy, and evidence-of-efficacy of 9911 drug, device, dietary, and surgical interventions for 563 severe, childhood, genetic diseases. The 421 (75%) diseases and 1527 (15%) effective interventions retained are integrated with 13 genetic disease information resources and appended to diagnostic reports (https://gtrx.radygenomiclab.com). This system provided correct diagnoses in four retrospectively and two prospectively tested infants. The Genome-to-Treatment system facilitates optimal outcomes in children with rapidly progressive genetic diseases.
PMID:35882841 | DOI:10.1038/s41467-022-31446-6
July 26, 2022
Newborn ScreeningRare DiseaseRPM for NICU and PICUrWGS
2022: A pivotal year for diagnosis and treatment of rare genetic diseases
Kingsmore SF
Cold Spring Harb Mol Case Stud. 2022 Feb 25:mcs.a006204. doi: 10.1101/mcs.a006204. Online ahead of print.
ABSTRACT
The start of 2022 is an inflection point in the development of diagnostics and treatments for rare genetic diseases in prenatal, pediatric, and adult individuals; the theme of this special issue. Here I briefly review recent developments in the latter two aspects of rare genetic disease diagnostics and treatments.
PMID:
35217563 | DOI:
10.1101/mcs.a006204
February 25, 2022
Rare DiseaseRPM for NICU and PICU
Activated phosphoinositide 3-kinase δ syndrome associated with nephromegaly, growth hormone deficiency, bronchiectasis: a case report
Craig M, Geng B, Wigby K, Phillips SA, Bakhoum C, Naheedy J, Cernelc-Kohan M.
Allergy Asthma Clin Immunol. 2022 Feb 21;18(1):15. doi: 10.1186/s13223-022-00655-5.
ABSTRACT
BACKGROUND: Activated phosphoinositide 3-kinase (PI3K) δ syndrome (APDS) is a rare form of primary immunodeficiency with 243 known cases reported in the literature. Known findings associated with the condition include recurrent sinusitis and bronchitis, bronchiectasis, immune cytopenias, mild developmental delay, splenomegaly, and lymphadenopathy. We report the case of a child with APDS accompanied by unique clinical features: nephromegaly and growth hormone deficiency with associated pituitary anatomic abnormality.
CASE PRESENTATION: The patient is a nine-year-old boy with a heterozygous de novo variant in phosphatidylinositol-4,5-bisphosphate 3-kinase catalytic subunit δ (p.E1021K), previously reported in association with APDS. Our patient, who had no family history of immunodeficiency, exhibits classic findings of this syndrome but also has unique features that extend the phenotypic spectrum of this disorder. At 5 years of age, the patient showed marked growth deceleration and was demonstrated to have growth hormone (GH) deficiency with associated pituitary anatomic abnormality. He started GH therapy with an excellent response. He additionally has bilateral nephromegaly of unclear etiology, microscopic hematuria and proteinuria, asthma, and has developed left hip pain with arthrocentesis consistent with oligoarticular juvenile idiopathic arthritis. At age nine, the patient was referred to genetics and whole exome sequencing revealed APDS. Though there was initial concern that GH may increase risk for malignancy as GH signals through the PI3K pathway, he was allowed to continue treatment as the PI3K pathway was considered constitutively active at baseline.
CONCLUSIONS: Our patient’s unique presentation adds to the clinical information regarding APDS, demonstrates the utility of genetic testing and illustrates the importance of a multidisciplinary collaborative approach in managing this complex syndrome.
PMID:
35189965 | DOI:
10.1186/s13223-022-00655-5
February 21, 2022
Rare Disease
Expanding the phenotypic and molecular spectrum of NFS1-related disorders that cause functional deficiencies in mitochondrial and cytosolic iron-sulfur cluster containing enzymes
Yang JH, Friederich MW, Ellsworth KA, Frederick A, Foreman E, Malicki D, Dimmock D, Lenberg J, Prasad C, Yu AC, Anthony Rupar C, Hegele RA, Manickam K, Koboldt DC, Crist E, Choi SS, Farhan SMK, Harvey H, Sattar S, Karp N, Wong T, Haas R, Van Hove JLK, Wigby K.
Hum Mutat. 2022 Jan 13. doi: 10.1002/humu.24330. Online ahead of print.
ABSTRACT
Iron-sulfur cluster proteins are involved in critical functions for gene expression regulation and mitochondrial bioenergetics including the oxidative phosphorylation system. The c.215G>A p.(Arg72Gln) variant in NFS1 has been previously reported to cause infantile mitochondrial complex II and III deficiency. We describe three additional unrelated patients with the same missense variant. Two infants with the same homozygous variant presented with hypotonia, weakness and lactic acidosis, and one patient with compound heterozygous p.(Arg72Gln) and p.(Arg412His) variants presented as a young adult with gastrointestinal symptoms and fatigue. Skeletal muscle biopsy from patients 1 and 3 showed abnormal mitochondrial morphology, and functional analyses demonstrated decreased activity in respiratory chain complex II and variably in complexes I and III. We found decreased mitochondrial and cytosolic aconitase activities but only mildly affected lipoylation of pyruvate dehydrogenase and 2-oxoglutarate dehydrogenase enzymes. Our studies expand the phenotypic spectrum and provide further evidence for the pathogenicity and functional sequelae of NFS1-related disorders with disturbances in both mitochondrial and cytosolic iron-sulfur cluster containing enzymes.
PMID:
35026043 | DOI:
10.1002/humu.24330
January 13, 2022
Rare Disease
DNA methylation episignature in Gabriele-de Vries syndrome
Cherik F, Reilly J, Kerkhof J, Levy M, McConkey H, Barat-Houari M, Butler KM, Coubes C, Lee JA, Le Guyader G, Louie RJ, Patterson WG, Tedder ML, Bak M, Hammer TB, Craigen W, Démurger F, Dubourg C, Fradin M, Franciskovich R, Frengen E, Friedman J, Palares NR, Iascone M, Misceo D, Monin P, Odent S, Philippe C, Rouxel F, Saletti V, Strømme P, Thulin PC, Sadikovic B, Genevieve D.
Genet Med. 2022 Jan 10:S1098-3600(21)05422-8. doi: 10.1016/j.gim.2021.12.003. Online ahead of print.
ABSTRACT
PURPOSE: Gabriele-de Vries syndrome (GADEVS) is a rare genetic disorder characterized by developmental delay and/or intellectual disability, hypotonia, feeding difficulties, and distinct facial features. To refine the phenotype and to better understand the molecular basis of the syndrome, we analyzed clinical data and performed genome-wide DNA methylation analysis of a series of individuals carrying a YY1 variant.
METHODS: Clinical data were collected for 13 individuals not yet reported through an international call for collaboration. DNA was collected for 11 of these individuals and 2 previously reported individuals in an attempt to delineate a specific DNA methylation signature in GADEVS.
RESULTS: Phenotype in most individuals overlapped with the previously described features. We described 1 individual with atypical phenotype, heterozygous for a missense variant in a domain usually not involved in individuals with YY1 pathogenic missense variations. We also described a specific peripheral blood DNA methylation profile associated with YY1 variants.
CONCLUSION: We reported a distinct DNA methylation episignature in GADEVS. We expanded the clinical profile of GADEVS to include thin/sparse hair and cryptorchidism. We also highlighted the utility of DNA methylation episignature analysis for classification of variants of unknown clinical significance.
PMID:
35027293 | DOI:
10.1016/j.gim.2021.12.003
January 10, 2022
Rare Disease
AHDC1 missense mutations in Xia-Gibbs syndrome
Khayat MM, Hu J, Jiang Y, Li H, Chander V, Dawood M, Hansen AW, Li S, Friedman J, Cross L, Bijlsma EK, Ruivenkamp CAL, Sansbury FH, Innis JW, O’Shea JO, Meng Q, Rosenfeld JA, McWalter K, Wangler MF, Lupski JR, Posey JE, Murdock D, Gibbs RA.
HGG Adv. 2021 Oct 14;2(4):100049. doi: 10.1016/j.xhgg.2021.100049. Epub 2021 Aug 10.
ABSTRACT
Xia-Gibbs syndrome (XGS; MIM: 615829) is a phenotypically heterogeneous neurodevelopmental disorder (NDD) caused by newly arising mutations in the AT-Hook DNA-Binding Motif-Containing 1 (AHDC1) gene that are predicted to lead to truncated AHDC1 protein synthesis. More than 270 individuals have been diagnosed with XGS worldwide. Despite the absence of an independent assay for AHDC1 protein function to corroborate potential functional consequences of rare variant genetic findings, there are also reports of individuals with XGS-like trait manifestations who have de novo missense AHDC1 mutations and who have been provided a molecular diagnosis of the disorder. To investigate a potential contribution of missense mutations to XGS, we mapped the missense mutations from 10 such individuals to the AHDC1 conserved protein domain structure and detailed the observed phenotypes. Five newly identified individuals were ascertained from a local XGS Registry, and an additional five were taken from external reports or databases, including one publication. Where clinical data were available, individuals with missense mutations all displayed phenotypes consistent with those observed in individuals with AHDC1 truncating mutations, including delayed motor milestones, intellectual disability (ID), hypotonia, and speech delay. A subset of the 10 reported missense mutations cluster in two regions of the AHDC1 protein with known conserved domains, likely representing functional motifs. Variants outside the clustered regions score lower for computational prediction of their likely damaging effects. Overall, de novo missense variants in AHDC1 are likely diagnostic of XGS when in silico analysis of their position relative to conserved regions is considered together with disease trait manifestations.
PMID:
34950897 | PMC:
PMC8694554 | DOI:
10.1016/j.xhgg.2021.100049
December 28, 2021
Rare Disease
Characterization of a patient-derived variant of GPX4 for precision therapy
Liu H, Forouhar F, Seibt T, Saneto R, Wigby K, Friedman J, Xia X, Shchepinov MS, Ramesh SK, Conrad M, Stockwell BR.
Nat Chem Biol. 2021 Dec 20. doi: 10.1038/s41589-021-00915-2. Online ahead of print.
ABSTRACT
Glutathione peroxidase 4 (GPX4), as the only enzyme in mammals capable of reducing esterified phospholipid hydroperoxides within a cellular context, protects cells from ferroptosis. We identified a homozygous point mutation in the GPX4 gene, resulting in an R152H coding mutation, in three patients with Sedaghatian-type spondylometaphyseal dysplasia. Using structure-based analyses and cell models, including patient fibroblasts, of this variant, we found that the missense variant destabilized a critical loop, which disrupted the active site and caused a substantial loss of enzymatic function. We also found that the R152H variant of GPX4 is less susceptible to degradation, revealing the degradation mechanism of the GPX4 protein. Proof-of-concept therapeutic treatments, which overcome the impaired R152H GPX4 activity, including selenium supplementation, selective antioxidants and a deuterated polyunsaturated fatty acid were identified. In addition to revealing a general approach to investigating rare genetic diseases, we demonstrate the biochemical foundations of therapeutic strategies targeting GPX4.
PMID:
34931062 | DOI:
10.1038/s41589-021-00915-2
December 28, 2021
Rare Disease
