[The relevance of molecular biology studies in the genetic counselling of Argentine retinoblastoma families].
OBJECTIVE
Evaluate the relevance of RB1 mutations detection in the genetic counselling of Argentine retinoblastoma families.


METHODS
We included in this study 34 Argentine families with bilateral and unilateral Retinoblastoma (Rb). 130 DNA samples from leukocytes, tumors and chorionic villus were analyzed by indirect and direct molecular biology assays like Southern blot, segregation of polymorphisms BamHI, Rbi4, XbaI y Rb 1.20 (PCR-RFLP, PCR-STR), PCR-heteroduplex and sequencing of RB1 gene.


RESULTS
Molecular biology analysis was informative in 18 out of 34 families studied (53%), 56% with bilateral and 44% with unilateral Rb. DNA tumor samples of 11 patients were available and could be studied by loss of heterozygosity (LOH) detection, that allowed us to identify the mutated RB1 allele in 9 (82%) patients. When tumor samples were not analized, the studies were informative only in 9 out of 23 patients (39%); we used direct mutation detection in 17 (41% informative) and indirect assays in 20 (60% informative) patients.


CONCLUSIONS
The results prove the necessity to have DNA tumor, when the patient has been enucleated, and emphasize the importance of direct mutation detection in families with early sporadic Rb without tumor sample. The RB1 molecular biology contributed to the adequate genetic counselling of Argentine patients and relatives and their appropriate early treatment planning (Arch Soc Esp Oftalmol 2009; 84: 557-562).
Parma
D L
DL
Universidad de Buenos Aires, Facultad de Farmacia y Bioquímica, Cátedra de Genética y Biología Molecular, Ciudad Autónoma de Buenos Aires, Buenos Aires, Argentina. dlparma@yahoo.com
Dalamon
V K
VK
Fernández
C
C
Szijan
I
I
Damel
A
A
D001118:Argentina; D002675:Child, Preschool; D005260:Female; D005817:Genetic Counseling; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D025202:Molecular Diagnostic Techniques; D009154:Mutation; D010375:Pedigree; D012175:Retinoblastoma / Q000235:genetics*; D016160:Retinoblastoma Protein / Q000235:genetics
D016160:Retinoblastoma Protein