Complete cytogenetic investigation of oocytes from a young cancer patient with the use of comparative genomic hybridisation reveals meiotic errors.
OBJECTIVE
The complete cytogenetic investigation of human oocytes and the corresponding first polar bodies (PBs) derived from an 18-year old female cancer patient.


METHODS
A whole-genome amplification method combined with comparative genomic hybridisation (CGH) was employed for the analysis of 14 oocytes and their corresponding first PBs.


RESULTS
Chromosome abnormalities were detected in two oocyte-PB complexes. One oocyte had lost X-chromosome material (23,X,-Xcht), while its corresponding first PB showed the reciprocal gain (23,X,+Xcht). Double aneuploidy involving loss of chromatids for chromosomes X and 21 was identified in another first PB (23,X,-21cht,-Xcht). Aneuploidy was attributed to unbalanced pre-division of chromatids at meiosis I.


CONCLUSIONS
Meiotic errors in chromosome segregation can occur even in oocytes derived from young women, confirming the existence of age-independent factors contributing to aneuploidy. Such factors are of relevance to fertility, miscarriage and preimplantation aneuploidy screening for the purposes of increasing IVF success rates. The reliability of CGH in examining the whole chromosome complement of a single cell and of being able to detect chromatid anomalies is confirmed by this study.
Fragouli
Elpida
E
UCL Centre for Preimplantation Genetic Diagnosis, Department of Obstetrics and Gynaecology, 86-96 Chenies Mews, University College London, London, WC1E 6HX, UK. efragouli@hotmail.com
Wells
Dagan
D
Doshi
Alpesh
A
Gotts
Sarah
S
Harper
Joyce C
JC
Delhanty
Joy D A
JD
D000293:Adolescent; D000782:Aneuploidy; D020732:Cytogenetic Analysis; D005260:Female; D023281:Genomics; D006801:Humans; D007247:Infertility, Female / Q000235:genetics*; D008540:Meiosis / Q000235:genetics*; D009190:Myelodysplastic Syndromes; D009865:Oocytes / Q000737:chemistry*; D016133:Polymerase Chain Reaction