Meiotic segregation and interchromosomal effect in the sperm of a double translocation carrier: a case report.
BACKGROUND
Infertility is a natural mechanism of selection intended to prevent the delivery of a child with malformations or mental retardation. Male infertility is closely related to chromosomal abnormalities. This study was focused on the analysis of meiotic segregation involving a Robertsonian translocation, 45,XY,der(13;13) [56]/45,XY,der(13;14) [44] and the evaluation of possible interchromosomal effects.


RESULTS
Hybridisation with LSI 13q14 and subtelomere 14q probes and WCP13 SpectrumGreen and WCP14 SpectrumOrange probes showed a high proportion of unbalanced gametes, corresponding to 71.2% of the spermatozoa. The disomic frequencies of the sexual chromosomes and chromosome 18 of the patient were higher (5.28% and 2.55%, respectively) than those of the control (0.6% and 0.59%, respectively).


CONCLUSIONS
Meiotic segregation studies in sperm are an important tool for genetic counselling of chromosomal aberrations, allowing for a prediction of the risks and consequent implications for the reproductive life. The patient with this rare translocation exhibited meiotic segregation fidelity, and a high rate of unbalanced gametes with disomic spermatozoa.
Juchniuk de Vozzi
Maria S
MS
Department of Genetics, School of Medicine of Ribeirão Preto, University of São Paulo, Ribeirão Preto, SP, Brazil. lrmartel@fmrp.usp.br.
Santos
Silvio A
SA
Pereira
Ciro S
CS
Cuzzi
Juliana F
JF
Laureano
Lucimar Af
LA
Franco
José G
JG
Martelli
Lucia
L