gms | German Medical Science

104th DOG Annual Meeting

21. - 24.09.2006, Berlin

Using formalin fixed and paraffin embedded tumour tissue and healthy eye tissue in retinoblastoma patients for detection of postzygous RB1 gene mutations

Meeting Abstract

  • M. Kontic - Kathedra for postgraduate studies in human genetics, School of Medicine, Belgrade
  • M. Kontic - Miltary Medical Academy, Belgrade, Serbia and Montenegro
  • V. Krstic - Institute of Ophthalmology, Clinical Centre of Serbia, Belgrade
  • D. Rasic - Institute of Ophthalmology, Clinical Centre of Serbia, Belgrade
  • Z. Latkovic - Institute of Ophthalmology, Clinical Centre of Serbia, Belgrade
  • A. Pestana - Oncolab, Instituto de Investigaciones Biomedicas "Alberto Sols", Madrid, Espana

Deutsche Ophthalmologische Gesellschaft e.V.. 104. Jahrestagung der Deutschen Ophthalmologischen Gesellschaft (DOG). Berlin, 21.-24.09.2006. Düsseldorf, Köln: German Medical Science; 2006. Doc06dogP139

The electronic version of this article is the complete one and can be found online at: http://www.egms.de/en/meetings/dog2006/06dog661.shtml

Published: September 18, 2006

© 2006 Kontic et al.
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Outline

Text

Objective

Detection of sporadic, postzygous RB1 mutation in DNA from formalin fixed, paraffin embeded tumor samples in retinoblastoma patients.

Methods

Whole blood from 13 unilateral retinoblastoma patients, 4 bilateral retinoblastoma patients and 22 of their parents as well as 13 tumor samples and healthy parts of ocular tissues from paraffin blocks available from the same patients were collected. DNA was extracted from all samples and linkage analysis and microsatellite markers method were performed. Microsatellite markers used are selected on bases of noticed heterozigosity in tumor tissues and their close connection to RB1 gene.

Results

Ten losses of heterozigosity (LOH) were found in the area of two intragene microsatellite loci within RB1 locus and of that 8 LOH in tumor DNA-s of unilateral, 2 LOH in bilateral patients and 2 big deletions of RB1 were identified. Linkage analysis revealed inheritance of RB1 alleles in 10 retinoblastoma families. A loss of heterozygosity was found in 63.16% of all tumors.

Conclusions

Knudson's "two hit" hypothesis on retinoblastoma etiology by detecting the second mutational event - loss of heterozigosity and great deletions in tumor DNA is confirmed. In our hands, DNA from whole blood offers better results in somatic mutations analysis then DNA from eye tissue in paraffin outside tumor, so that it is better to use whole blood in this type of research.