Chromosomal Mutations & their effects

1. Chromosomal Mutations & their effects

2. Karyotype • A picture of the chromosomes of an individual or a species, including number, form, and size of the chromosomes. • Often used to diagnosis chromosomal abnormalities.

3. Chromosomes • Humans have 23 pairs • 22 pairs are autosomes • 1 pair are sex chromosomes • (women = XX, men = XY) • Chromosomes have a centromere that holds the chromatids (two parts of the chromosome) together. • The top ½ of the chromosome is called the “p” arm and the bottom ½ is “q”

4. Nondisjunction Disorder • Nondisjunction is the failure of chromosome pairs to separate during meiosis (making of gametes – sex cells) • it can cause some gametes to gain an extra chromosome and others to lose one • Monosomy = A chromosome having no homologue (matching chromosome) • Trisomy =The condition of having three copies of a given chromosome in each somatic (body) cell rather than the normal number of two.

7. Normal Male Karyotype Normal Female Karyotype

8. Turners Syndrome 1 in 5,000 births 45 chromosomes X only #23 MonosomyNondisjunction

9. Turners Syndrome 96-98% do not survive to birth No menstruation No breast development No hips Broad shoulders and neck

10. Cri-Du-Chat Syndrome 1 in 216,000 births 46 chromosomes XY or XX #5 Deletion of upper arm of chromosome

11. Cri-Du-Chat Syndrome Moon-shaped face Heart disease Mentally retarded Malformed larynx Normal lifespan

12. Aniridia-Wilms Tumor Syndrome 1 in 50,000,000 births 46 chromosomesXY or XX #11 Deletion of upper arm

13. Aniridia-Wilms Tumor Syndrome Mentally retarded Growth retarded Blindness Tumors on kidneys Short lifespan

14. Thirteen Q Deletion Syndrome 1 in 500,000 births 46 chromosomesXY or XX #13 Deletion of lower arm

15. Thirteen Q Deletion Syndrome Mentally retarded Deformed face No thumbs Heart disease Short lifespan

16. Prader-Willi Syndrome 1 in 5,000,000 births46 chromosomes XY=97% XX=3% #15 Deletion of lower arm

17. Prader-Willi Syndrome Small bird-like head Mentally retarded Respiratory problems Obesity Short lifespan

18. Eighteen Q Deletion Syndrome 1 in 10,000,000 births 46 chromosomesXY or XX #18 Deletion of lower arm

19. Eighteen Q Deletion Syndrome Mentally retarded Heart disease Abnormal hands and feet Large eyes Large ears Normal lifespan

20. Cat-Eye Syndrome 1 in 1,000,000 births 46 chromosomesXY or XX #22 Deletion of bottom arm

21. Cat-Eye Syndrome Fused fingers and toes Mentally retarded Small jaw Heart problems Normal lifespan

22. Four-Ring Syndrome 1 in 10,000,000 births 46 chromosomesXY or XX #4 Inversion

23. Four-Ring Syndrome Cleft palate Club feet Testes don’t descend Short lifespan

24. Down Syndrome Trisomy Down Syndrome 1 in 31,000 births46 chromosomes XY=97% XX=3% #14/21 Translocation 1 in 1,250 births 47 chromosomesXY or XX #21 Trisomy Nondisjunction

25. Down Syndrome Short, broad hands Stubby fingers Rough skin Impotency in males Mentally retarded Small round face Protruding tongue Short lifespan

26. Patau’s Trisomy Syndrome 1 in 14,000 births 47 chromosomesXY or XX #13 Trisomy Nondisjunction

27. Patau’s Trisomy Syndrome Small head Small or missing eyes Heart defects Extra fingers Abnormal genitalia Mentally retarded Cleft palate Most die a few weeks after birth

28. Edward’s Trisomy Syndrome 1 in 4,400 births47 chromosomes XX=80% XY=20% #18 Trisomy Nondisjunction

29. Edward’s Trisomy Syndrome Small head Mentally retarded Internal organ abnormalities 90% die before 5 months of age

30. Jacob’s Syndrome 1 in 1,800 births 47 chromosomesXYY only #23 Trisomy Nondisjunction

31. Jacob’s Syndrome ? Normal physicallyNormal mentally Increase in testosterone Acne Normal lifespan

32. Kleinfelter Syndrome 1 in 1,100 births 47 chromosomesXXY only #23 Trisomy Nondisjunction

33. Kleinfelter Syndrome Scarce beard Longer fingers and arms Sterile Delicate skin Low mental ability Normal lifespan

34. Triple X Syndrome 1 in 2,500 births 47 chromosomesXXX only #23 TrisomyNondisjunction

35. Triple X Syndrome Normally physically Normal mentally Tall Fertile normal lifespan