Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 5 de 5
Filter
1.
Hum Mol Genet ; 29(22): 3662-3678, 2020 12 04.
Article in English | MEDLINE | ID: mdl-33276377

ABSTRACT

The genetic causes of multiple congenital anomalies are incompletely understood. Here, we report novel heterozygous predicted loss-of-function (LoF) and predicted damaging missense variants in the WW domain binding protein 11 (WBP11) gene in seven unrelated families with a variety of overlapping congenital malformations, including cardiac, vertebral, tracheo-esophageal, renal and limb defects. WBP11 encodes a component of the spliceosome with the ability to activate pre-messenger RNA splicing. We generated a Wbp11 null allele in mouse using CRISPR-Cas9 targeting. Wbp11 homozygous null embryos die prior to E8.5, indicating that Wbp11 is essential for development. Fewer Wbp11 heterozygous null mice are found than expected due to embryonic and postnatal death. Importantly, Wbp11 heterozygous null mice are small and exhibit defects in axial skeleton, kidneys and esophagus, similar to the affected individuals, supporting the role of WBP11 haploinsufficiency in the development of congenital malformations in humans. LoF WBP11 variants should be considered as a possible cause of VACTERL association as well as isolated Klippel-Feil syndrome, renal agenesis or esophageal atresia.


Subject(s)
Abnormalities, Multiple/genetics , DNA-Binding Proteins/genetics , Haploinsufficiency/genetics , Kidney/metabolism , RNA Splicing Factors/genetics , Abnormalities, Multiple/pathology , Anal Canal/abnormalities , Anal Canal/pathology , Animals , Esophagus/abnormalities , Esophagus/metabolism , Esophagus/pathology , Heart Defects, Congenital/genetics , Heart Defects, Congenital/pathology , Heterozygote , Humans , Kidney/abnormalities , Kidney/pathology , Limb Deformities, Congenital/genetics , Limb Deformities, Congenital/pathology , Loss of Function Mutation/genetics , Mice , RNA Splicing/genetics , Spine/abnormalities , Spine/pathology , Trachea/abnormalities , Trachea/pathology
2.
Hum Mol Genet ; 29(4): 566-579, 2020 03 13.
Article in English | MEDLINE | ID: mdl-31813956

ABSTRACT

Congenital heart disease (CHD) is the most common birth defect and brings with it significant mortality and morbidity. The application of exome and genome sequencing has greatly improved the rate of genetic diagnosis for CHD but the cause in the majority of cases remains uncertain. It is clear that genetics, as well as environmental influences, play roles in the aetiology of CHD. Here we address both these aspects of causation with respect to the Notch signalling pathway. In our CHD cohort, variants in core Notch pathway genes account for 20% of those that cause disease, a rate that did not increase with the inclusion of genes of the broader Notch pathway and its regulators. This is reinforced by case-control burden analysis where variants in Notch pathway genes are enriched in CHD patients. This enrichment is due to variation in NOTCH1. Functional analysis of some novel missense NOTCH1 and DLL4 variants in cultured cells demonstrate reduced signalling activity, allowing variant reclassification. Although loss-of-function variants in DLL4 are known to cause Adams-Oliver syndrome, this is the first report of a hypomorphic DLL4 allele as a cause of isolated CHD. Finally, we demonstrate a gene-environment interaction in mouse embryos between Notch1 heterozygosity and low oxygen- or anti-arrhythmic drug-induced gestational hypoxia, resulting in an increased incidence of heart defects. This implies that exposure to environmental insults such as hypoxia could explain variable expressivity and penetrance of observed CHD in families carrying Notch pathway variants.


Subject(s)
Gene-Environment Interaction , Genetic Predisposition to Disease , Genomics/methods , Heart Defects, Congenital/pathology , Mutation , Receptor, Notch1/genetics , Animals , Case-Control Studies , Female , Heart Defects, Congenital/etiology , Heart Defects, Congenital/genetics , Humans , Male , Mice , Mice, Inbred C57BL , Mice, Knockout , Exome Sequencing
3.
Am J Hum Genet ; 106(1): 129-136, 2020 01 02.
Article in English | MEDLINE | ID: mdl-31883644

ABSTRACT

Birth defects occur in up to 3% of all live births and are the leading cause of infant death. Here we present five individuals from four unrelated families, individuals who share similar phenotypes with disease-causal bi-allelic variants in NADSYN1, encoding NAD synthetase 1, the final enzyme of the nicotinamide adenine dinucleotide (NAD) de novo synthesis pathway. Defects range from the isolated absence of both kidneys to multiple malformations of the vertebrae, heart, limbs, and kidney, and no affected individual survived for more than three months postnatally. NAD is an essential coenzyme for numerous cellular processes. Bi-allelic loss-of-function mutations in genes required for the de novo synthesis of NAD were previously identified in individuals with multiple congenital abnormalities affecting the heart, kidney, vertebrae, and limbs. Functional assessments of NADSYN1 missense variants, through a combination of yeast complementation and enzymatic assays, show impaired enzymatic activity and severely reduced NAD levels. Thus, NADSYN1 represents an additional gene required for NAD synthesis during embryogenesis, and NADSYN1 has bi-allelic missense variants that cause NAD deficiency-dependent malformations. Our findings expand the genotypic spectrum of congenital NAD deficiency disorders and further implicate mutation of additional genes involved in de novo NAD synthesis as potential causes of complex birth defects.


Subject(s)
Carbon-Nitrogen Ligases with Glutamine as Amide-N-Donor/genetics , Congenital Abnormalities/etiology , Multiple Organ Failure/etiology , Mutation, Missense , NAD/deficiency , Alleles , Amino Acid Sequence , Congenital Abnormalities/pathology , Female , Genotype , Gestational Age , Humans , Infant , Infant, Newborn , Male , Multiple Organ Failure/pathology , Pedigree , Phenotype , Pregnancy , Sequence Homology
4.
Mol Cell Biol ; 29(10): 2889-98, 2009 May.
Article in English | MEDLINE | ID: mdl-19289503

ABSTRACT

In Saccharomyces cerevisiae, transcriptional silencing occurs at the cryptic mating-type loci (HML and HMR), telomeres, and ribosomal DNA (rDNA; RDN1). Silencing in the rDNA is unusual in that polymerase II (Pol II) promoters within RDN1 are repressed by Sir2 but not Sir3 or Sir4. rDNA silencing unidirectionally spreads leftward, but the mechanism of limiting its spreading is unclear. We searched for silencing barriers flanking the left end of RDN1 by using an established assay for detecting barriers to HMR silencing. Unexpectedly, the unique sequence immediately adjacent to RDN1, which overlaps a prominent cohesin binding site (CARL2), did not have appreciable barrier activity. Instead, a fragment located 2.4 kb to the left, containing a tRNA(Gln) gene and the Ty1 long terminal repeat, had robust barrier activity. The barrier activity was dependent on Pol III transcription of tRNA(Gln), the cohesin protein Smc1, and the SAS1 and Gcn5 histone acetyltransferases. The location of the barrier correlates with the detectable limit of rDNA silencing when SIR2 is overexpressed, where it blocks the spreading of rDNA heterochromatin. We propose a model in which normal Sir2 activity results in termination of silencing near the physical rDNA boundary, while tRNA(Gln) blocks silencing from spreading too far when nucleolar Sir2 pools become elevated.


Subject(s)
DNA, Ribosomal/genetics , Gene Expression Regulation, Fungal , Gene Silencing , Heterochromatin/metabolism , Histone Deacetylases/metabolism , Saccharomyces cerevisiae , Silent Information Regulator Proteins, Saccharomyces cerevisiae/metabolism , Sirtuins/metabolism , Cell Cycle Proteins/genetics , Cell Cycle Proteins/metabolism , Chromosomal Proteins, Non-Histone/genetics , Chromosomal Proteins, Non-Histone/metabolism , DNA, Ribosomal/metabolism , Genome, Fungal , Histone Acetyltransferases/metabolism , Histone Deacetylases/genetics , Microarray Analysis , RNA Polymerase III/metabolism , RNA, Transfer, Gln/genetics , RNA, Transfer, Gln/metabolism , Saccharomyces cerevisiae/genetics , Saccharomyces cerevisiae/metabolism , Silent Information Regulator Proteins, Saccharomyces cerevisiae/genetics , Sirtuin 2 , Sirtuins/genetics , Cohesins
5.
IUBMB Life ; 60(3): 159-64, 2008 Mar.
Article in English | MEDLINE | ID: mdl-18380007

ABSTRACT

Nuclear receptor (NR) coregulators are key modulators of hormone signaling. Discovery of steroid receptor RNA activator (SRA), a coregulator that is active as a RNA, transformed thinking in the field of hormone action. The subsequent identification of SRA-binding coregulator proteins, including p68, SHARP and more recently SLIRP, has provided important insight into SRA's mechanism of action and potentially offers new opportunities to target NR signaling pathways for therapeutic gain. Here we outline advances in the field of NR coregulator biology, with a bias on recent progress in understanding SRA-protein interactions.


Subject(s)
RNA, Untranslated/metabolism , RNA/metabolism , Receptors, Cytoplasmic and Nuclear/metabolism , Signal Transduction/physiology , Animals , DNA-Binding Proteins , Homeodomain Proteins/metabolism , Humans , Mitochondria/metabolism , MyoD Protein/metabolism , Nuclear Proteins/metabolism , RNA, Long Noncoding , RNA, Untranslated/genetics , RNA-Binding Proteins/metabolism , Tumor Suppressor Protein p53/metabolism
SELECTION OF CITATIONS
SEARCH DETAIL
...