Chromosome territories, X;Y translocation and Premature Ovarian Failure: is there a relationship?
BACKGROUND
Premature ovarian failure (POF) is a secondary hypergonadotrophic amenorrhea occurring before the age of 40 and affecting 1-3% of females. Chromosome anomalies account for 6-8% of POF cases, but only few cases are associated with translocations involving X and Y chromosomes.This study shows the cytogenetic and molecular analysis of a POF patient came to our attention as she developed a left ovary choriocarcinoma at the age of 10 and at 14 years of age she presented secondary amenorrhea with elevated levels of gonadotropins.


RESULTS
Breakpoint position on X and Y chromosomes was investigated using Fluorescent In Situ Hybridisation (FISH) with a panel of specific BAC probes, microsatellite analysis and evaluation of copy number changes and loss of heterozigosity by Affymetrix(R) GeneChip platform (Santa Clara, CA, USA). Patient's karyotype resulted 46, X, der(Y)t(X;Y)(q13.1;q11.223). X inactivation study was assessed by RBA banding and showed preferential inactivation of derivative chromosome. The reciprocal spatial disposition of sexual chromosome territories was investigated using whole chromosome painting and centromeres probes: patient's results didn't show a significant difference in comparison to normal controls.


CONCLUSIONS
The peculiar clinical case come to our attention highlighted the complexity of POF aetiology and of the translocation event, even if our results seem to exclude any effect on nuclear organisation. POF phenotype could be partially explained by skewed X chromosome inactivation that influences gene expression.
Lissoni
Sara
S
Department of Neuroscience and Biomedical Technologies, University of Milan-Bicocca, via Cadore 48, 20052, Monza, Italy. leda.dalpra@unimib.it.
Baronchelli
Simona
S
Villa
Nicoletta
N
Lucchini
Valeria
V
Betri
Enrico
E
Cavalli
Pietro
P
Dalprà
Leda
L