Εκτίμηση της δυνατότητας ανίχνευσης του μωσαϊκισμού με μικροσυστοιχίες CGH+SNP

Postgraduate Thesis uoadl:2810665 376 Read counter

Unit:
Κατεύθυνση Ιατρική Γενετική: Κλινική και Εργαστηριακή Κατεύθυνση
Library of the School of Health Sciences
Deposit date:
2018-10-16
Year:
2018
Author:
Vasilopoulou Maria
Supervisors info:
Μαρία Τζέτη, Αναπληρώτρια Καθηγήτρια, Ιατρική, ΕΚΠΑ
Ιωάννα Traeger-Συνοδινού, Καθηγήτρια, Ιατρική, ΕΚΠΑ
Ελένη Φρυσίρα, Καθηγήτρια, Ιατρική, ΕΚΠΑ
Original Title:
Εκτίμηση της δυνατότητας ανίχνευσης του μωσαϊκισμού με μικροσυστοιχίες CGH+SNP
Languages:
Greek
Translated title:
Εκτίμηση της δυνατότητας ανίχνευσης του μωσαϊκισμού με μικροσυστοιχίες CGH+SNP
Summary:
Introduction: Mosaicism describes the presence in an individual or a tissue of at least two cell lineages that differ genetically but are derived from a single zygote. Mosaicism can be categorized into three types: somatic, gonadal and gonosomal. An increasing number of studies have highlighted the significance of mosaicism and although mosaic abnormalities are a relatively frequent event, some mosaic patients may not be diagnosed due to failure to recognize clinical indications, technical limitations of the methodology that is used or inappropriate sampling tissue.
Purpose: In this study, the aim was to evaluate the threshold of mosaicism detection using oligonucleotide-based microarray CGH+SNP.
Materials and Methods: Τwo samples with known abnormalities on chromosomes 15 and X were combined with appropriate quantities of gender-matched normal DNA in order to mimic 75%, 50%, 25%, 20%, 15% and 10% levels of mosaicism. These artificial mosaic samples were hybridized to Agilent 4x180K and 8x60K oligo-aCGH. All abnormal and normal DNA had previously been tested by array-CGH.
Results: According to our results, oligo array-CGH can detect the presence of mosaicism in levels as low as 15-20%. However, at such low levels of mosaicism, the results may be inaccurate. Moreover, we observed a decrease in the rate of log2ratio as the degree of mosaicism reduced.
Conclusion: The results of this study are consistent with the literature that oligonucleotide-based array-CGH can accurately detect levels of mosaicism >25-30%. More studies with a larger number of samples should be done in order to accurately predict the degree of mosaicism detection from array CGH. Finally, combining more than one methods (chromosome analysis, FISH, aCGH, QF-PCR) seems to offer a more accurate diagnosis of the level of mosaicism.
Main subject category:
Health Sciences
Keywords:
Microarrays, Oligo array-CGH, Mosaicism, Threshold of detection
Index:
No
Number of index pages:
0
Contains images:
Yes
Number of references:
102
Number of pages:
75
Μεταπτυχιακή Διπλωματική Εργασία_Βασιλοπούλου Α. Μαρία.pdf (2 MB) Open in new window