This document provides information about various prenatal and postnatal cytogenetic examinations used to detect chromosomal abnormalities: 1. Prenatal examinations include chorionic villi sampling, amniocentesis, and cordocentesis to obtain fetal tissue for chromosomal analysis between 11-24 weeks of pregnancy. Ultrasound can detect increased nuchal translucency and biochemical tests measure fetal protein levels. 2. Postnatal examinations analyze chromosomes from peripheral blood, skin, bone marrow or other tissues from individuals being tested for possible chromosomal causes of developmental issues, infertility or tumors. 3. The karyotyping process cultures lymphocytes to grow and arrest in metaphase for chromosome staining, imaging and analysis

1. Practical 5 Chromosomal analysis Karyotyping

6. Prenatal examinations fetus chorion amnion umbilical cord Chorionic villi sampling (CVS) Amniocentesis Cordocentesis 10. 11. 12. 13. 14. 15. 16. 17. 18. 19. 20. 21. 22. 23. 24. End of prenatal examinations Weeks of pregnancy

7. Chorionic villi

8. Chorionic villi sampling since 11th week of pregnancy Transabdominal CVS Transvaginal (transcervical) CVS – biopsy from the placenta and examining the baby's chromosomes

9. Chorionic villi sampling Tissue of chorionic villi Examination under the stereomicroscope

10. Schedule of prenatal examinations Chorionic villi sampling Amniocentesis Cordocentesis 11. 16. 20. Pregnancy (weeks) 12 th – 20 th week Ultrasound Biochemical test in 16 th week AFP, hCG, E3, PAPP 24. End of prenatal examinations

11. Ultrasound examination i s offer ed to all pregnant women An instrument called a transducer emits sound waves that bounce or echo off internal organs. This information is relayed to a computer, which produces an image on a nearby screen.

13. Ultrasound examination

18. Amniocentesis 15 th – 16 th week of pregnancy

20. Amniocentesis

26. Prenatal examinations fetus chorion amnion umbilical cord Chorionic villi sampling (CVS) Amniocentesis Cordocentesis 10. 11. 12. 13. 14. 15. 16. 17. 18. 19. 20. 21. 22. 23. 24. End of all prenatal examinations Weeks of pregnancy

27. For all of invasive prenatal samplings written consent of the mother is necessary.

33. Solid staining of chromosomes We use only Giemsa-Romanowski solution 6 – 12 13 – 15 19 – 20 21 – 22 4 – 5

34. G-banding (GTG) Trypsin + Giemsa

35. Each G-band has concrete number : Xq27.3 Chromosome X with G-bands

40. Put the slides back to boxes, please.

42. See you next week!