Search results for "gene deletion"
showing 10 items of 159 documents
A role for the peroxisomal 3-ketoacyl-CoA thiolase B enzyme in the control of PPARα-mediated upregulation of SREBP-2 target genes in the liver.: ThB …
2011
International audience; Peroxisomal 3-ketoacyl-CoA thiolase B (Thb) catalyzes the final step in the peroxisomal β-oxidation of straight-chain acyl-CoAs and is under the transcription control of the nuclear hormone receptor PPARα. PPARα binds to and is activated by the synthetic compound Wy14,643 (Wy). Here, we show that the magnitude of Wy-mediated induction of peroxisomal β-oxidation of radiolabeled (1-(14)C) palmitate was significantly reduced in mice deficient for Thb. In contrast, mitochondrial β-oxidation was unaltered in Thb(-/-) mice. Given that Wy-treatment induced Acox1 and MFP-1/-2 activity at a similar level in both genotypes, we concluded that the thiolase step alone was respons…
Mitochondrial biogenesis fails in secondary biliary cirrhosis in rats leading to mitochondrial DNA depletion and deletions
2011
Chronic cholestasis is characterizedby mitochondrial dysfunction, associated with loss of mitochondrialmembrane potential, decreased activities of respiratory chaincomplexes, and ATP production. Our aim was to determine themolecular mechanisms that link long-term cholestasis to mitochondrialdysfunction. We studied a model of chronic cholestasis inducedby bile duct ligation in rats. Key sensors and regulators of theenergetic state and mitochondrial biogenesis, mitochondrial DNA(mtDNA)-to-nuclear DNA (nDNA) ratio (mtDNA/nDNA) relativecopy number, mtDNA deletions, and indexes of apoptosis (BAX,BCL-2, and cleaved caspase 3) and cell proliferation (PCNA) wereevaluated. Our results show that long…
Clinical Significance of Rare Copy Number Variations in Epilepsy A Case-Control Survey Using Microarray-Based Comparative Genomic Hybridization
2012
Objective To perform an extensive search for genomic rearrangements by microarray-based comparative genomic hybridization in patients with epilepsy. Design Prospective cohort study. Setting Epilepsy centers in Italy. Patients Two hundred seventy-nine patients with unexplained epilepsy, 265 individuals with nonsyndromic mental retardation but no epilepsy, and 246 healthy control subjects were screened by microarray-based comparative genomic hybridization. Main Outcomes Measures Identification of copy number variations (CNVs) and gene enrichment. Results Rare CNVs occurred in 26 patients (9.3%) and 16 healthy control subjects (6.5%) (P = .26). The CNVs identified in patients were larger (P = …
Identification of the novel D297fsX318 PINK1 mutation and phenotype variation in a family with early-onset Parkinson's disease
2008
Herein we first describe a novel homozygous single nucleotide deletion in PINK1 exon 4 (889delG) which results in a loss of kinase domain on the PINK1 protein (D297fsX318). This mutation was identified in two brothers with early-onset Parkinson disease (EOPD) from a Sicilian consanguineous family. Of note, while one of the two patients developed mental deterioration and psychiatric problems, the other showed no cognitive decline. The present study supports the view that PINK1 is a pathogenic gene in some Italian families with EOPD and contributes to define the PINK1-associated phenotype. Herein we first describe a novel homozygous single nucleotide deletion in PINK1 exon 4 (889delG) which r…
Clinical manifestations and management of four children with Pearson syndrome.
2011
Pearson marrow-pancreas syndrome is a fatal disorder mostly diagnosed during infancy and caused by mutations of mitochondrial DNA. We hereby report on four children affected by Pearson syndrome with hematological disorders at onset. The disease was fatal to three of them and the fourth one, who received hematopoietic stem cell transplantation, died of secondary malignancy. In this latter patient transplantation corrected hematological and non-hematological issues like metabolic acidosis, and we therefore argue that it could be considered as a useful option in an early stage of the disease.
A novel two base pair deletion in the factor V gene associated with severe factor V deficiency
2001
We studied a family in which the proband, a 13-year-old boy, had unmeasurable plasma levels of coagulation factor V antigen and activity. Clinical symptoms were severe, with several episodes of haemorrhages in the mucosal tracts (gastrointestinal, nose and urinary) and recurrent haemarthroses that caused permanent arthropathy. Sequence analysis of the factor V gene demonstrated the presence of a novel 2 base pair (bp) homozygous deletion in exon 13 at positions 2833-2834. This mutation, present in the heterozygous state in the asymptomatic mother and absent in the healthy brother, introduced a frameshift and a premature stop at codon 900. This would predict the synthesis of a truncated fact…
Targeted next-generation sequencing of deafness genes in hearing-impaired individuals uncovers informative mutations
2014
Purpose: Targeted next-generation sequencing provides a remarkable opportunity to identify variants in known disease genes, particularly in extremely heterogeneous disorders such as nonsyndromic hearing loss. The present study attempts to shed light on the complexity of hearing impairment. Methods: Using one of two next-generation sequencing panels containing either 80 or 129 deafness genes, we screened 30 individuals with nonsyndromic hearing loss (from 23 unrelated families) and analyzed 9 normal-hearing controls. Results: Overall, we found an average of 3.7 variants (in 80 genes) with deleterious prediction outcome, including a number of novel variants, in individuals with nonsyndromic h…
RNA cytosine methylation by Dnmt2 and NSun2 promotes tRNA stability and protein synthesis.
2012
The function of cytosine-C5 methylation, a widespread modification of tRNAs, has remained obscure, particularly in mammals. We have now developed a mouse strain defective in cytosine-C5 tRNA methylation, by disrupting both the Dnmt2 and the NSun2 tRNA methyltransferases. Although the lack of either enzyme alone has no detectable effects on mouse viability, double mutants showed a synthetic lethal interaction, with an underdeveloped phenotype and impaired cellular differentiation. tRNA methylation analysis of the double-knockout mice demonstrated complementary target-site specificities for Dnmt2 and NSun2 and a complete loss of cytosine-C5 tRNA methylation. Steady-state levels of unmethylate…
Mutation analysis of the SPG4 gene in Italian patients with pure and complicated forms of spastic paraplegia
2010
Mutations in the SPG4 gene are the most common causes of hereditary spastic paraplegia (HSP) accounting for up to 40% of autosomal dominant (AD) forms and 12-18% of sporadic cases. The phenotype associated with HSP due to mutations in the SPG4 gene tends to be pure. There is increasing evidence, however, of patients with complicated forms of spastic paraplegia in which SPG4 mutations were identified. A cohort of 38 unrelated Italian patients with spastic paraplegia, of which 24 had a clear dominant inheritance and 14 were apparently sporadic, were screened for mutations in the SPG4 gene.We identified 11 different mutations, six of which were novel (p.Glu143GlyfsX8, p.Tyr415X, p.Asp548Asn, c…
A Novel Deletion in the Thyrotropin Beta-Subunit Gene Identified by Array Comparative Genomic Hybridization Analysis Causes Central Congenital Hypoth…
2014
<b><i>Background:</i></b> Isolated central congenital hypothyroidism (ICCH) is rare but important. Most ICCH patients are diagnosed later, which results in severe growth failure and intellectual disability. <b><i>Objective:</i></b> We describe a boy with ICCH due to a large homozygous <i>TSHβ </i>gene deletion. <b><i>Results:</i></b> A 51-day-old male Turkish infant, whose parents were first cousins, was admitted for evaluation of prolonged jaundice. His clinical appearance was compatible with hypothyroidism. Venous thyrotropin (TSH) was undetectably low, with a subsequent low free T4 and a low free T3, sugg…