scholarly journals Molecular mechanism in a rare autosomal recessive case of xeroderma pigmentosum - a case report

2014 ◽  
Vol 03 (03) ◽  
pp. 178-183
Author(s):  
Vijaya Ramanathan ◽  
Anand Ramanathan
Keyword(s):  
Case Report ◽  
Xeroderma Pigmentosum ◽  
Chromosomal Instability ◽  
Autosomal Recessive ◽  
Excision Repair ◽  
Sister Chromatid Exchanges ◽  
Ocular Manifestations ◽  
Nucleotide Excision ◽  
Chromosomal Breaks ◽  
Chromatid Exchanges

AbstractChromosomal instability syndromes are a special group of disorders of cytogenetic interest which comprises of several rare, autosomal recessive conditions. Following exposure to sunlight, excessive chromosomal instability, breakage, defective nucleotide excision repair in DNA, defective apoptosis and increased susceptibility to neoplasia occurs. Xeroderma pigmentosum (XP) is characterised by the presence of chromosomal breakages, associated with increased frequency of sister chromatid exchanges. This is a case report of a 6 year old, male child having XP with dermal and ocular manifestations. Chromosomal breaks in chromosomal spread are seen. If it occurs in families, consanguinous marriages should be avoided; appropriate genetic counselling suggested and simple sun guarding techniques with appropriate protection from UV exposure can reduce the morbidity in these patients.

scholarly journals SISTER CHROMATID EXCHANGE IN XERODERMA PIGMENTOSUM CELLS THAT ARE DEFECTIVE IN DNA EXCISION REPAIR OR POST-REPLICATION REPAIR

Genetics ◽  
1975 ◽  
Vol 81 (2) ◽  
pp. 349-355
Author(s):  
Sheldon Wolff ◽  
Judy Bodycote ◽  
G H Thomas ◽  
James E Cleaver
Keyword(s):  
Dna Repair ◽  
Sister Chromatid ◽  
Xeroderma Pigmentosum ◽  
Excision Repair ◽  
Sister Chromatid Exchanges ◽  
Normal Limits ◽  
Repair Enzymes ◽  
Sister Chromatids ◽  
Post Replication Repair ◽  
Chromatid Exchanges

ABSTRACT The formation of sister chromatid exchanges has been postulated to depend upon the action of DNA repair enzymes. Our experiments with various human cell lines show that the yield of sister chromatid exchanges is within normal limits in both excision-repair-defective and post-replication-repair-defective cells from the autosomal recessive disease, xeroderma pigmentosum. These results indicate that hypotheses invoking known DNA repair processes to account for the recombination of sister chromatids are inadequate and that the exact enzymatic processes are as yet unknown.

Increase of sister chromatid exchanges in excision repair deficient xeroderma pigmentosum

1989 ◽  
Vol 81 (3) ◽  
Author(s):  
Rosa Aledo ◽  
Georges Renault ◽  
Marguerite Prieur ◽  
MarieFran�oise Avril ◽  
Bertrand Chr�tien ◽  
...  
Keyword(s):  
Sister Chromatid ◽  
Xeroderma Pigmentosum ◽  
Excision Repair ◽  
Sister Chromatid Exchanges ◽  
Chromatid Exchanges

scholarly journals Xeroderma Pigmentosum Diagnosis Using a Flow Cytometry-Based Nucleotide Excision Repair Assay

2018 ◽  
Vol 138 (2) ◽  
pp. 467-470 ◽  
Author(s):  
Eiji Nakano ◽  
Seiji Takeuchi ◽  
Ryusuke Ono ◽  
Mariko Tsujimoto ◽  
Taro Masaki ◽  
...  
Keyword(s):  
Flow Cytometry ◽  
Nucleotide Excision Repair ◽  
Xeroderma Pigmentosum ◽  
Excision Repair ◽  
Nucleotide Excision

scholarly journals The crystal structure of human XPG, the xeroderma pigmentosum group G endonuclease, provides insight into nucleotide excision DNA repair

2020 ◽  
Vol 48 (17) ◽  
pp. 9943-9958
Author(s):  
Rocío González-Corrochano ◽  
Federico M Ruiz ◽  
Nicholas M I Taylor ◽  
Sonia Huecas ◽  
Srdja Drakulic ◽  
...  
Keyword(s):  
Dna Binding ◽  
Xeroderma Pigmentosum ◽  
Mutational Analysis ◽  
Excision Repair ◽  
Genetic Diseases ◽  
Complementation Group ◽  
Repair System ◽  
High Plasticity ◽  
Starting Point ◽  
Nucleotide Excision

Abstract Nucleotide excision repair (NER) is an essential pathway to remove bulky lesions affecting one strand of DNA. Defects in components of this repair system are at the ground of genetic diseases such as xeroderma pigmentosum (XP) and Cockayne syndrome (CS). The XP complementation group G (XPG) endonuclease cleaves the damaged DNA strand on the 3′ side of the lesion coordinated with DNA re-synthesis. Here, we determined crystal structures of the XPG nuclease domain in the absence and presence of DNA. The overall fold exhibits similarities to other flap endonucleases but XPG harbors a dynamic helical arch that is uniquely oriented and defines a gateway. DNA binding through a helix-2-turn-helix motif, assisted by one flanking α-helix on each side, shows high plasticity, which is likely relevant for DNA scanning. A positively-charged canyon defined by the hydrophobic wedge and β-pin motifs provides an additional DNA-binding surface. Mutational analysis identifies helical arch residues that play critical roles in XPG function. A model for XPG participation in NER is proposed. Our structures and biochemical data represent a valuable tool to understand the atomic ground of XP and CS, and constitute a starting point for potential therapeutic applications.

Nucleotide Excision Repair in the Three Domains of Life

2011 ◽  
Vol 2 (1) ◽  
Author(s):  
David A Farnell
Keyword(s):  
Dna Repair ◽  
Nucleotide Excision Repair ◽  
Xeroderma Pigmentosum ◽  
Excision Repair ◽  
Human Diseases ◽  
Repair Pathway ◽  
Functional Conservation ◽  
Wide Range ◽  
Nucleotide Excision ◽  
Domains Of Life

Nucleotide excision repair (NER) is a vital DNA repair pathway which acts on a wide range of helix-distorting lesions. The importance of this pathway is highlighted by its functional conservation throughout evolution and by several human diseases, such as xeroderma pigmentosum, which are caused by a defective NER pathway. This review summarizes the NER mechanisms present in all three domains of life: eukaryotes, bacteria, and archaea.

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