Clinical, cytogenetic, and molecular testing of Argentine patients with retinoblastoma.
OBJECTIVE
The purpose of this study is to determine the clinical, chromosomal, and molecular characteristics of Argentine patients with unilateral and bilateral retinoblastoma.


METHODS
Eighty-six patients belonging to 82 families were studied; 59% of them were examined during the first year of life. Leukocoria was the most common reason for consultation. Other presenting signs were strabismus and glaucoma. Enucleation of the affected eye was performed in 85% of the cases and the complication rate was 13%.


RESULTS
An appropriate therapy allowed the survival of 84 of the 86 patients. Two children with malformations and growth retardation had an abnormal karyotype with a deletion in 13q14. Segregation analysis of polymorphic sites within the retinoblastoma gene and the parental origin of the allele lost in the tumor were analyzed in 30 of the 82 families. Five mutant alleles transmitted through the germline and six de novo germline mutant alleles were identified in 12 patients with hereditary retinoblastoma. Most de novo germline mutant alleles were paternally derived. Molecular analysis of nonhereditary retinoblastoma showed loss of heterozygosity in three of eight cases. From these, two maternal alleles and one paternal allele were lost, thus not indicating a significant difference in the parental origin for the lost allele.


CONCLUSIONS
These data are useful for deoxyribonucleic acid diagnosis of susceptibility to retinoblastoma in relatives of hereditary patients, even if mutations have not been identified.
Arbetman
A
A
Genética y Biología Molecular, Facultad de Farmacia y Bioquímica, University of Buenos Aires, Argentina.
Abdala
M
M
Fandiño
A
A
Herrera
J
J
Baranzini
S
S
Borelina
D
D
Parma
D
D
Manzitti
J
J
Barreiro
C
C
Giliberto
F
F
Szijan
I
I
D000483:Alleles; D001118:Argentina; D002882:Chromosomes, Human, Pair 13 / Q000235:genetics; D020732:Cytogenetic Analysis; D015353:Eye Enucleation; D005260:Female; D017353:Gene Deletion; D018095:Germ-Line Mutation; D006801:Humans; D007223:Infant; D007621:Karyotyping; D019656:Loss of Heterozygosity; D008297:Male; D010375:Pedigree; D019572:Retinal Neoplasms / Q000235:genetics* / Q000503:physiopathology*; D012175:Retinoblastoma / Q000235:genetics* / Q000503:physiopathology*; D016019:Survival Analysis