Salvatrice A Lauricella, Martina Busè, Simona Cavani, Helenia C Cuttaia, Michela Malacarne, Marcella V Mazara, Mauro Pierluigi and Maria Piccione
Mosaicism in association with derivative chromosomes is a well-known fact. Derivative chromosomes often tend to rearrange and/or be reduced in size during karyotype evolution, because of their instability. This can determine the disappearance of a derivative chromosome at least in the most frequently studied tissue, the peripheral blood.
We report on a case of a rare complex structural chromosomal abnormality in mosaic, in a female patient who was referred to us for infertility. Patient’s karyotype was performed twice: The first time two cell lines were detected (a 45 chromosomes and a 46 chromosomes cell line respectively) both with a derivative chromosome 18, resulting from a translocation between chromosome 18 and 21. Six months later, a second karyotype showed only the 45 chromosome cell line. FISH analysis and array-CGH, subsequently performed to better characterize this complex rearrangement, showed a partial deletion of the short and long arm of chromosome 21.