Karyotyping spermatozoa after spermatogonial stem cell transplantation by array-CGH

Thanks to advances in chemo- and radiotherapy, cure rates of childhood cancers are high. Long-term survivors face significant adverse effects such as spermatogenic failure and infertility. For adult men sperm banking before treatment may circumvent this adverse effect. However, pre-pubertal patients cannot benefit from this option. A possible solution for the preservation of their fertility is spermatogonial stem cell transplantation (SSCT). The aim of this study is to examine whether spermatozoa obtained after SSCT show genetic abnormalities.
Five to ten months after SSCT epididymal spermatozoa were isolated to perform array-CGH.
Chromosal aberrations, such as polyploidy or aneuploidy could not be detected in spermatozoa from transplanted males. The spermatozoa of two offspring showed a single deviation. The spermatozoa of one male offspring showed a deletion of the H2-M1 gene on chromosome 17. The aberration in the spermatozoa from the other male offspring showed a duplication of the Slc7a12 gen on chromosome 3. This needs to be confirmed.
Our findings show that SSCT can restore the fertility in an otherwise infertile individual without causing significant chromosomal aberrations. These results are important and reassuring for further implementation of SSCT in a clinical setting.