Human Reproduction, Vol. 16, No. 1, 63-66,
January 2001
© 2001 European Society of Human Reproduction and Embryology
Pseudo dicentric chromosome (5;21): a rare example of maternal germline mosaicism: Case Report
1 Institute for Human Genetics, University of Göttingen and 2 Department of Obstetrics and Gynaecology, University of Göttingen, Germany
Karyotyping of a malformed male newborn revealed the unbalanced karyotype of 46,XY, psudic(5;21)(q12;p13), +5 resulting in trisomy for the short arm of chromosome 5 and partial trisomy for 5q. Both parents had normal karyotypes in their peripheral blood lymphocytes. A second pregnancy ended in a miscarriage at 16 weeks gestation, sonographically 12 weeks. Karyotyping of chorionic villi from the abortus revealed the same unbalanced karyotype that had been identified in the first child. Fluorescence in-situ hybridization analysis confirmed a trisomy 5p. Microsatellite marker analysis ruled out illegitimacy and proved the maternal origin of the trisomic section of chromosome 5. Extended chromosome analysis of 60 metaphase cells from maternal skin fibroblasts and 40 metaphase cells from lymphocytes did not reveal mosaicism for psudic(5;21). These findings suggest the presence of a maternal germline mosaicism.
Key words: genetic counselling/germ line mosaicism/gonadal mosaicism/parental origin/translocation
3 To whom correspondence should be addressed at: Institut für Humangenetik, Universität Göttingen, Heinrich-Düker-Weg 12, D-37073 Göttingen, Germany. E-mail: wengel{at}gwdg.de