1. Karyotypes& Chromosome Mutations

3. Look at the karyotype for the mutation

5. A karyotype is an organized profile of a person's chromosomes.
In a karyotype, chromosomes are arranged and numbered by size, from largest to smallest.

6. Karyotypes are done by doctors to diagnose some genetic disorders

7. A normal human karyotype has 46 chromosomes (23 pairs):
#1-22 are called autosomes
#23 are called sex chromosomes

9. XX~ female XY~ male

10. RECALL…What is a mutation?
Any mistake or change in DNA sequence
Mutations can only be inherited if they occur in sex cells
Two types: Gene or chromosomal

11. Chromosomal mutation: affects whole or part of a chromosome
Gene mutation:
Changes to the bases in the DNA of ONE gene

12. Chromosomal Mutations
Change in # of chromosomes OR structure of the chromosome
Abnormality detected on karyotype
Five types

13. Can YOU spot the chromosomal mutation??

15. 1) Deletion
Loss of all or part of a chromosome

17. 2) Duplication
Produce extra copies of parts of a chromosome.

19. 3) Inversion
Part of a chromosome breaks out and reinserts backwards.

21. 4) Translocation
Part of a chromosome breaks off & attaches to another chromosome

22. 5) Nondisjunction
Improper separation of homologous chromosomes during meiosis
Results in extra or missing chromosomes in gametes

24. Remember—normally have 2 copies of each
Types of Nondisjunction
Trisomy~ 3 copies of a chromosome
Monosomy~ 1 copy of a chromosome
Remember—normally have 2 copies of each

25. Can you spot the mutation?

26. Down Syndrome – Trisomy 21
Intellectual and developmental disabilities
may have heart defects and respiratory problems

27. 2. Look at the karyotype for the mutation

28. Trisomy 18 (Edwards syndrome)
abnormal brain function that is very severe
Heart, Kidney, intestinal problems
Severe developmental delays
usually die within years old g/

29. 3. Look at the karyotype for the mutation

30. Trisomy 13 (Patau syndrome)
Extra fingers or toes
Cleft lip or palate, Close set eyes, Scalp defects
Problems with heart and brain structure
die within 1-2 years old
somy13.org/

31. 4. Look at the karyotype for the mutation

32. Trisomy on Sex Chromosomes
XYY Syndrome – Extra Y
normal appearance, may be taller than average, delayed development of speech and motor skills, not likely to be inherited
XXX Syndrome – Triple X
normal appearance, may be taller than average, delayed development of speech and motor skills, not likely to be inherited, sometimes sterile/infertile

33. 5. Look at the karyotype for the mutation

34. Klinefelter’s Syndrome – XXY
Sterile/infertile, normal appearance
May be taller than average
May have less body or facial hair
delayed development of speech and motor skills
NOT more inclined toward homosexuality or bisexuality
ets/fs31.pdf

35. 6. Look at the karyotype for the mutation

36. Monosomy Missing part or all of second X chromosome
Turner Syndrome – X
Missing part or all of second X chromosome
usually sterile/infertile
Shorter than average height, heart and kidney problems, Normal intelligence
99% embryos miscarriage or stillborn

37. Look at the karyotype for the mutation

38. What is the mutation?
Boy or Girl?

39. Trisomy 18

41. Trisomy 13 (Patau syndrome)
Extra fingers or toes
Cleft lip or palate (deformed lips)
Heart and brain structure problems
Die within 1-2 years of age

42. Trisomy on Sex Chromosomes
XYY Syndrome – Extra Y
Males only, taller than average, learning disabilities, behavior issues
XXX Syndrome – Triple X
Female only, Delayed learning ability, low speech abilities, Hit milestones slower

43. What is the mutation?
Boy or Girl?

44. Turner’s Syndrome 45,X Webbed neck Infertile
Swollen hands & feet at birth
Heart defects

45. Chromosomal Mutations Videos
Visualizing Nondisjunction