Classification of chromosomes

Classification of chromosomes

1. Classification of chromosomes DR: Eman Farghaly By:Hasnaa Salama 390 ALEXANDRIA FACULTY OF Medicine

2. Chromosomes are classified according to length into 7 major groups :A,B,C,D,E,F&G

3. Group A Chromosomes 1: 3 Chromosomes 1 & 2 have similar lengths , but… Chromosmes 1& 3 are METACENTRIC ,but….

4. Group B Chromosomes 4 & 5. Chromosomes 4 & 5 are very similar ! They are large & sub- metacentric .

5. GROUP C Chromosomes 6:12 &(XX) or only one X. middle-sized & Metacentric or Sub- metacentric . Female 16 C Chrom . Male 15 C Chrom . or

6. Group D Chromosomes 13:15. middle-sized & Acrocentric . They have Satellites. Easy to be distinguished!

7. Group E Chromosomes 16:18. Smaller than chrom . D P-arm of chrom . 17 &18 is shorter than chrom . 16. 16  Metacentric . 17&18  sub- metacentric

8. Group F Chromosomes 19&20. They are Metacentric . Chromosomes 19 and 20 can’t be distinguished!

9. Group G Chromosomes 21,22 & Y. Chrom . 21&22 are the smallest pair. They have Satellites. Chrom . Y is longer than 21&22. Y does not have Satellites .

10. Spectral Karyotyping

11. Summary Classification of chromosomes according to length>>> 7 groups (A,B,C,D,E,F &G). Spectral karyotyping >>>> leukemia