Pathogenic TP53 germline variants cause young-onset breast cancer and other cancers of the Li-Fraumeni syndrome (LFS) spectrum, but the clinical consequences of partial-loss-of function TP53 variants are incompletely understood. In the consecutive cohort of Palestinian breast cancer patients of the Middle East Breast Cancer Study (MEBCS), breast cancer risk among TP53 p. R181C heterozygotes was 50% by age 50 y and 81% by age 80 y.
View Article and Find Full Text PDFThe vast majority of deeply intronic genomic variants are benign, but some extremely rare or private deep intronic variants lead to exonification of intronic sequence with abnormal transcriptional consequences. Damaging variants of this class are likely underreported as causes of disease for several reasons: Most clinical DNA and RNA testing does not include full intronic sequences; many of these variants lie in complex repetitive regions that cannot be aligned from short-read whole-genome sequence; and, until recently, consequences of deep intronic variants were not accurately predicted by in silico tools. We evaluated the frequency and consequences of rare deep intronic variants for families severely affected with breast, ovarian, pancreatic, and/or metastatic prostate cancer, but with no causal variant identified by any previous genomic or cDNA-based approach.
View Article and Find Full Text PDFThe forces of evolution-mutation, selection, migration, and genetic drift-shape the genetic architecture of human traits, including the genetic architecture of complex neuropsychiatric illnesses. Studying these illnesses in populations that are diverse in genetic ancestry, historical demography, and cultural history can reveal how evolutionary forces have guided adaptation over time and place. A fundamental truth of shared human biology is that an allele responsible for a disease in anyone, anywhere, reveals a gene critical to the normal biology underlying that condition in everyone, everywhere.
View Article and Find Full Text PDFInborn errors of immunity (IEIs) are monogenic disorders that predispose patients to immune dysregulation, autoimmunity, and infection. Autoimmune cytopenias, such as immune thrombocytopenia (ITP) and Evans syndrome (a combination of ITP and autoimmune hemolytic anemia), are increasingly recognized phenotypes of IEI. Although recent findings suggest that IEIs may commonly underlie pediatric ITP and Evans syndrome, its prevalence in adult patients with these disorders remains undefined.
View Article and Find Full Text PDFJAMA Otolaryngol Head Neck Surg
March 2023
Importance: In the US, most childhood-onset bilateral sensorineural hearing loss is genetic, with more than 120 genes and thousands of different alleles known. Primary treatments are hearing aids and cochlear implants. Genetic diagnosis can inform progression of hearing loss, indicate potential syndromic features, and suggest best timing for individualized treatment.
View Article and Find Full Text PDFObjective: To determine the yield of genetic diagnoses using chromosomal microarray (CMA) and trio whole exome sequencing (WES), separately and combined, among patients with cryptogenic cerebral palsy (CP).
Methods: Trio WES of patients with prior CMA analysis for cryptogenic CP, defined as disabling, non-progressive motor symptoms beginning before the age of 3 years without known cause.
Results: Given both CMA analysis and trio WES, clinically significant genetic findings were identified for 58% of patients (26 of 45).
Background: Most patients with childhood-onset immune dysregulation, polyendocrinopathy, and enteropathy have no genetic diagnosis for their illness. These patients may undergo empirical immunosuppressive treatment with highly variable outcomes.
Objective: We sought to determine the genetic basis of disease in patients referred with Immune dysregulation, polyendocrinopathy, enteropathy, X-linked-like (IPEX-like) disease, but with no mutation in FOXP3; then to assess consequences of genetic diagnoses for clinical management.
The Carolina Breast Cancer Study (CBCS) phases I-II was a case-control study of biological and social risk factors for invasive breast cancer that enrolled cases and controls between 1993 and 1999. Case selection was population-based and stratified by ancestry and age at diagnosis. Controls were matched to cases by age, self-identified race, and neighborhood of residence.
View Article and Find Full Text PDFMutations in more than 150 genes are responsible for inherited hearing loss, with thousands of different, severe causal alleles that vary among populations. The Israeli Jewish population includes communities of diverse geographic origins, revealing a wide range of deafness-associated variants and enabling clinical characterization of the associated phenotypes. Our goal was to identify the genetic causes of inherited hearing loss in this population, and to determine relationships among genotype, phenotype, and ethnicity.
View Article and Find Full Text PDFCurrent clinical approaches for mutation discovery are based on short sequence reads (100-300 bp) of exons and flanking splice sites targeted by multigene panels or whole exomes. Short-read sequencing is highly accurate for detection of single nucleotide variants, small indels and simple copy number differences but is of limited use for identifying complex insertions and deletions and other structural rearrangements. We used CRISPR-Cas9 to excise complete and genomic regions from lymphoblast cells of patients with breast cancer, then sequenced these regions with long reads (>10 000 bp) to fully characterise all non-coding regions for structural variation.
View Article and Find Full Text PDFTelomere biology disorders (TBDs) present heterogeneously, ranging from infantile bone marrow failure associated with very short telomeres to adult-onset interstitial lung disease (ILD) with normal telomere length. Yield of genetic testing and phenotypic spectra for TBDs caused by the expanding list of telomere genes in adults remain understudied. Thus, we screened adults aged ≥18 years with a personal and/or family history clustering hematologic disorders and/or ILD enrolled on The University of Chicago Inherited Hematologic Disorders Registry for causative variants in 13 TBD genes.
View Article and Find Full Text PDFMutations in BRCA1 and BRCA2 cause deficiencies in homologous recombination repair (HR), resulting in repair of DNA double-strand breaks by the alternative non-homologous end-joining pathway, which is more error prone. HR deficiency of breast tumors is important because it is associated with better responses to platinum salt therapies and PARP inhibitors. Among other consequences of HR deficiency are characteristic somatic-mutation signatures and gene-expression patterns.
View Article and Find Full Text PDFContext: NKX2-2 is a crucial transcription factor that enables specific β-cell gene expression. Nkx2-2(-/-) mice manifest with severe neonatal diabetes and changes in β-cell progenitor fate into ghrelin-producing cells. In humans, recessive NKX2-2 gene mutations have been recently reported as a novel etiology for neonatal diabetes, with only 3 cases known worldwide.
View Article and Find Full Text PDFProc Natl Acad Sci U S A
August 2020
The genetic characterization of a common phenotype for an entire population reveals both the causes of that phenotype for that place and the power of family-based, population-wide genomic analysis for gene and mutation discovery. We characterized the genetics of hearing loss throughout the Palestinian population, enrolling 2,198 participants from 491 families from all parts of the West Bank and Gaza. In Palestinian families with no prior history of hearing loss, we estimate that 56% of hearing loss is genetic and 44% is not genetic.
View Article and Find Full Text PDFDeficiency of the endoplasmic reticulum transmembrane protein ARV1 leads to epileptic encephalopathy in humans and in mice. ARV1 is highly conserved, but its function in human cells is unknown. Studies of yeast arv1 null mutants indicate that it is involved in a number of biochemical processes including the synthesis of sphingolipids and glycosylphosphatidylinositol (GPI), a glycolipid anchor that is attached to the C-termini of many membrane bound proteins.
View Article and Find Full Text PDFDevelopmental epileptic encephalopathies are devastating disorders characterized by intractable epileptic seizures and developmental delay. Here, we report an allelic series of germline recessive mutations in UGDH in 36 cases from 25 families presenting with epileptic encephalopathy with developmental delay and hypotonia. UGDH encodes an oxidoreductase that converts UDP-glucose to UDP-glucuronic acid, a key component of specific proteoglycans and glycolipids.
View Article and Find Full Text PDFProc Natl Acad Sci U S A
December 2019
Mutations responsible for inherited disease may act by disrupting normal transcriptional splicing. Such mutations can be difficult to detect, and their effects difficult to characterize, because many lie deep within exons or introns where they may alter splice enhancers or silencers or introduce new splice acceptors or donors. Multiple mutation-specific and genome-wide approaches have been developed to evaluate these classes of mutations.
View Article and Find Full Text PDFObjectives: Loss-of-function mutations of BMPR1A cause juvenile polyposis syndrome (JPS), but large genomic deletions in BMPR1A are rare, reported in few families only, and data regarding the associated phenotype are limited.
Methods: We investigated clinical features and genomic data of 7 extended seemingly unrelated families with a genomic deletion of the entire coding region of BMPR1A. We defined mutation size, mutation prevalence, and tumor pathogenesis using whole-genome sequencing, targeted genotyping, and haplotype analysis.
Myeloid neoplasms, including myelodysplastic syndromes (MDS), are genetically heterogeneous disorders driven by clonal acquisition of somatic mutations in hematopoietic stem and progenitor cells (HPCs). The order of premalignant mutations and their impact on HPC self-renewal and differentiation remain poorly understood. We show that episomal reprogramming of MDS patient samples generates induced pluripotent stem cells from single premalignant cells with a partial complement of mutations, directly informing the temporal order of mutations in the individual patient.
View Article and Find Full Text PDFSurvival from malignant mesothelioma, particularly pleural mesothelioma, is very poor. For patients with breast, ovarian, or prostate cancers, overall survival is associated with increased sensitivity to platinum chemotherapy due to loss-of-function mutations in DNA repair genes. The goal of this project was to evaluate, in patients with malignant mesothelioma, the relationship between inherited loss-of-function mutations in DNA repair and other tumor suppressor genes and overall survival following platinum chemotherapy.
View Article and Find Full Text PDFPurpose: Congenital mirror movement disorder (CMMD) is characterized by unintended, nonsuppressible, homologous mirroring activity contralateral to the movement on the intended side of the body. In healthy controls, unilateral movements are accompanied with predominantly contralateral cortical activity, whereas in CMMD, in line with the abnormal behavior, bilateral cortical activity is observed for unilateral motor tasks. However, task-related activities in subcortical structures, which are known to play critical roles in motor actions, have not been investigated in CMMD previously.
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