1. Human Genetic Disorders
Their symptoms…

2. Albinism inherit genes that do not make the proper amounts of pigment!

3. Albinism
Homozygous
recessive

4. Cystic Fibrosis (CF) homozygous recessive trait on (autosomes)*

5. Sickle Cell Anemia (substitution of adenine for thymine) homozygous recessive*

6. Sickle Cell Anemia

7. Polydactyly (autosomal) homozygous recessive*

8. Polydactyly

9. Webbing of Fingers (autosomal)!

10. Webbing of Toes (autosomal)*

11. Klinefelters Syndrome XXY Nondisjunction
Tallness with extra long arms and legs
Abnormal body proportions (long legs, short trunk)
Enlarged breasts
Lack of facial and body hair
Small firm testes
Small penis
Lack of ability to produce sperm
Diminished sex drive
Sexual dysfunction
Learning disabilities
Personality impairment

12. Klinefelters syndrome presenting “leg ulcers”
1/50 –1/1000 are born
With KS
Extra X chr. #47
Due to anaphase lag
(fails to separate)
Chronic venus
Insufficiencies
Obesity
Reduced testosterone
Therapy (cause)

13. Turners syndrome X Nondisjunction
Turner syndrome is a birth defect caused by the absence of an X chromosome in some or all cells of a female, which inhibits sexual development and usually causes infertility.
MONOSOMY – zygote with 45 chromosomes

14. Continue…
In Turner syndrome, an error occurring very early in development results in an abnormal number and arrangement of chromosomes. Most commonly, an individual with Turner syndrome will be born with 45 chromosomes in each cell rather than 46. The missing chromosome is an X chromosome. The affected person is always female

15. Mosaics…
More than half of all girls with Turner syndrome are mosaics, which means that the mutation occurs in some but not all cells of their body. Therefore, Turner syndrome can vary in severity. The fewer the affected cells, the milder the disease
1 / 2,500 female births have turners syndrome

16. Symptoms of Turner Syndrome
short stature
webbed skin of the neck
abnormal eye features (drooping eyelids)
abnormal bone development, such as a "shield-shaped," broad flat chest
absent or retarded development of secondary sexual characteristics that normally appear at puberty, including sparse pubic hair and small breasts
coarctation (narrowing) of the aorta
bicuspid aortic valve
infertility
dry eyes
absence of menstruation

17. Webbed Neck

18. Webbed Neck

19. Turner’s syndrome

20. Mom and her daughter with Turner’s Syndrome*

21. Down’s Syndrome nondisjunction*

22. Children with Down’s syndrome Trisomy 21*

23. Who gets dwarfism and bone dysplasias?
Bone dysplasias and dwarfism are rare. The most common type of dwarfism (achondroplasia) occurs in one in 15,000 children.
A defective gene that stops bone from growing in the usual way causes most bone dysplasias. Sometimes this gene is passed on from a parent to a child (genetic).
Much more often, though, the condition arises from a new change in the gene (spontaneous genetic mutation), and the baby is the first in her family to be affected.

24. Achondroplasia
Autosomal
dominant

25. *

26. Thumbelina has dwarfism*

27. Huntington’s Disease (HD) (autosomal dominant allele)*

28. Symptoms of HD Mild forgetfulness and irritability
Appears between yrs. Old
Loss of muscle control
Uncontrollable physical spasms
Severe mental illness
Eventually death

29. Phenylketonura (PKU) Autosomal homozygous dominant
Lacking amino acid phenylalanine
Loss of motor skills, mental dibilitation
Treatment: diet change, restricted diet

30. Tay Sach Autosomal recessive Normal 1st 6 months
Deterioration of nerve cells
Treatment: enzyme replacement therapy

31. Cri DU Chat Syndrome Missing piece of chromosome #5
Most are not inheritted
High pitch cry that sounds like a cat
Intellectual disability and delayed development
Small head size
Treatment: behavior modified programs

32. Marfan’s Syndrome Dominant
Defective connective tissue, tall, long limbs, thin fingers (heart valves and aorta)
Treatment: as problems arise

33. Muscular Dystrophy Genetic or malnurishment (prenatal)
Progressive skeletal weakness

34. Hemophilia X linked disorder Lack of blood clotting factor (platelets)
Treatment: transfusions platelets

35. Vocab… Pleiotropy = one gene for many characteristics. Ex: sickle cell
Polygenic = many genes for one characteristic. Ex: skin color, height