Genetic Disorders. Overview 6 billion base pairs of DNA ~ 3 meters of DNA Approximately 30,000 –...
-
Upload
arlene-baldwin -
Category
Documents
-
view
214 -
download
0
Transcript of Genetic Disorders. Overview 6 billion base pairs of DNA ~ 3 meters of DNA Approximately 30,000 –...
![Page 1: Genetic Disorders. Overview 6 billion base pairs of DNA ~ 3 meters of DNA Approximately 30,000 – 70,000 genes * Approximately 80-100,000 proteins These.](https://reader030.fdocuments.us/reader030/viewer/2022032702/56649cf15503460f949c037a/html5/thumbnails/1.jpg)
Genetic Disorders
![Page 2: Genetic Disorders. Overview 6 billion base pairs of DNA ~ 3 meters of DNA Approximately 30,000 – 70,000 genes * Approximately 80-100,000 proteins These.](https://reader030.fdocuments.us/reader030/viewer/2022032702/56649cf15503460f949c037a/html5/thumbnails/2.jpg)
Overview• 6 billion base pairs of DNA
~ 3 meters of DNA
• Approximately 30,000 – 70,000 genes
* Approximately 80-100,000 proteins
• These genes are spread across 24 different chromosomes
**One chromosome each from each parent, for a total of 23 pairs, or 46 chromosomes per cell**
![Page 3: Genetic Disorders. Overview 6 billion base pairs of DNA ~ 3 meters of DNA Approximately 30,000 – 70,000 genes * Approximately 80-100,000 proteins These.](https://reader030.fdocuments.us/reader030/viewer/2022032702/56649cf15503460f949c037a/html5/thumbnails/3.jpg)
• All normal human cells (except sex cells) have 46 chromosomes, half of which are from mom, and the other half are from dad. (23 pairs of homologous chromosomes)
• 2 sets (46) of homologous chromosomes =DIPLOID
![Page 4: Genetic Disorders. Overview 6 billion base pairs of DNA ~ 3 meters of DNA Approximately 30,000 – 70,000 genes * Approximately 80-100,000 proteins These.](https://reader030.fdocuments.us/reader030/viewer/2022032702/56649cf15503460f949c037a/html5/thumbnails/4.jpg)
• Pictures of chromosomes grouped in order and in pairs = Karyotype
![Page 5: Genetic Disorders. Overview 6 billion base pairs of DNA ~ 3 meters of DNA Approximately 30,000 – 70,000 genes * Approximately 80-100,000 proteins These.](https://reader030.fdocuments.us/reader030/viewer/2022032702/56649cf15503460f949c037a/html5/thumbnails/5.jpg)
Chromosome Number
Homologous chromosomes
Autosomal chromosomes
= non sex determining chromosomes, same shaped homologous
Sex chromosomes
Karyotype Normal male
Dark bands = Genes
Diploid!
![Page 6: Genetic Disorders. Overview 6 billion base pairs of DNA ~ 3 meters of DNA Approximately 30,000 – 70,000 genes * Approximately 80-100,000 proteins These.](https://reader030.fdocuments.us/reader030/viewer/2022032702/56649cf15503460f949c037a/html5/thumbnails/6.jpg)
Sex chromosomes:
X = female, Y = male
X/Y = male
X/X = female
![Page 7: Genetic Disorders. Overview 6 billion base pairs of DNA ~ 3 meters of DNA Approximately 30,000 – 70,000 genes * Approximately 80-100,000 proteins These.](https://reader030.fdocuments.us/reader030/viewer/2022032702/56649cf15503460f949c037a/html5/thumbnails/7.jpg)
![Page 8: Genetic Disorders. Overview 6 billion base pairs of DNA ~ 3 meters of DNA Approximately 30,000 – 70,000 genes * Approximately 80-100,000 proteins These.](https://reader030.fdocuments.us/reader030/viewer/2022032702/56649cf15503460f949c037a/html5/thumbnails/8.jpg)
…still sex determination
• Probability of having a boy or a girl.
X Y
X
X
Dad
Mom
X Y
X Girl Boy
X Girl Boy
XX
XX
XY
XY
50% chance for boy
50% chance for girl
![Page 9: Genetic Disorders. Overview 6 billion base pairs of DNA ~ 3 meters of DNA Approximately 30,000 – 70,000 genes * Approximately 80-100,000 proteins These.](https://reader030.fdocuments.us/reader030/viewer/2022032702/56649cf15503460f949c037a/html5/thumbnails/9.jpg)
Chromosomal disorders
• What if you have extra chromosome?
• What if you are missing a chromosome?
Chromosomal disorders usually:
Increase chance of having disorders, such as mental retardation, sterility, and decrease life expectancy.
![Page 10: Genetic Disorders. Overview 6 billion base pairs of DNA ~ 3 meters of DNA Approximately 30,000 – 70,000 genes * Approximately 80-100,000 proteins These.](https://reader030.fdocuments.us/reader030/viewer/2022032702/56649cf15503460f949c037a/html5/thumbnails/10.jpg)
Is anything wrong?
Chromosome 21 trisomy Down syndrome
Male
![Page 11: Genetic Disorders. Overview 6 billion base pairs of DNA ~ 3 meters of DNA Approximately 30,000 – 70,000 genes * Approximately 80-100,000 proteins These.](https://reader030.fdocuments.us/reader030/viewer/2022032702/56649cf15503460f949c037a/html5/thumbnails/11.jpg)
Trisomy 21( extra on the 21st)- Down Syndrome
• Redundant neck fold/flat occipital (back of the head)• Low set ears• Protruding/large tongue* Wide space between 1st & 2nd toes
![Page 12: Genetic Disorders. Overview 6 billion base pairs of DNA ~ 3 meters of DNA Approximately 30,000 – 70,000 genes * Approximately 80-100,000 proteins These.](https://reader030.fdocuments.us/reader030/viewer/2022032702/56649cf15503460f949c037a/html5/thumbnails/12.jpg)
![Page 13: Genetic Disorders. Overview 6 billion base pairs of DNA ~ 3 meters of DNA Approximately 30,000 – 70,000 genes * Approximately 80-100,000 proteins These.](https://reader030.fdocuments.us/reader030/viewer/2022032702/56649cf15503460f949c037a/html5/thumbnails/13.jpg)
Trisomy 13 (47,XY,+13) – Cleft Lip
![Page 14: Genetic Disorders. Overview 6 billion base pairs of DNA ~ 3 meters of DNA Approximately 30,000 – 70,000 genes * Approximately 80-100,000 proteins These.](https://reader030.fdocuments.us/reader030/viewer/2022032702/56649cf15503460f949c037a/html5/thumbnails/14.jpg)
Cleft Lip- a split or indentation in the lip of a newborn baby.
![Page 15: Genetic Disorders. Overview 6 billion base pairs of DNA ~ 3 meters of DNA Approximately 30,000 – 70,000 genes * Approximately 80-100,000 proteins These.](https://reader030.fdocuments.us/reader030/viewer/2022032702/56649cf15503460f949c037a/html5/thumbnails/15.jpg)
Sex Chromosome Abnormalities
• Turner syndrome
• Klinefelter syndrome (XXY)
• Triple X
• XYY
![Page 16: Genetic Disorders. Overview 6 billion base pairs of DNA ~ 3 meters of DNA Approximately 30,000 – 70,000 genes * Approximately 80-100,000 proteins These.](https://reader030.fdocuments.us/reader030/viewer/2022032702/56649cf15503460f949c037a/html5/thumbnails/16.jpg)
Is anything wrong?
X
Turner’s syndrome
![Page 17: Genetic Disorders. Overview 6 billion base pairs of DNA ~ 3 meters of DNA Approximately 30,000 – 70,000 genes * Approximately 80-100,000 proteins These.](https://reader030.fdocuments.us/reader030/viewer/2022032702/56649cf15503460f949c037a/html5/thumbnails/17.jpg)
Turner Syndrome• 45 Chromosomes , only one sex chromosome• The incidence is about 1 in 5000 female births
but this is only the tip of the iceberg because 99% of Turner syndrome embryos are spontaneously aborted.
• Individuals are very short, they are usually infertile.
• Characteristic body shape changes include a broad chest with widely spaced nipples and may include a webbed neck.
• IQ and lifespan are unaffected.
![Page 18: Genetic Disorders. Overview 6 billion base pairs of DNA ~ 3 meters of DNA Approximately 30,000 – 70,000 genes * Approximately 80-100,000 proteins These.](https://reader030.fdocuments.us/reader030/viewer/2022032702/56649cf15503460f949c037a/html5/thumbnails/18.jpg)
![Page 19: Genetic Disorders. Overview 6 billion base pairs of DNA ~ 3 meters of DNA Approximately 30,000 – 70,000 genes * Approximately 80-100,000 proteins These.](https://reader030.fdocuments.us/reader030/viewer/2022032702/56649cf15503460f949c037a/html5/thumbnails/19.jpg)
Is anything wrong?
XXY
Klinefelter’s syndrome
![Page 20: Genetic Disorders. Overview 6 billion base pairs of DNA ~ 3 meters of DNA Approximately 30,000 – 70,000 genes * Approximately 80-100,000 proteins These.](https://reader030.fdocuments.us/reader030/viewer/2022032702/56649cf15503460f949c037a/html5/thumbnails/20.jpg)
• Klinefelter Syndrome 47,XXY*The incidence at birth is about 1 in 1000 males. *Testes are small and fail to produce normal levels of testosterone which leads to breast growth in about 40% of cases and to poorly developed secondary sexual characteristics.
*Males are sterile.
*These males are taller and thinner than average and generally have a slight reduction in IQ (10-15 points below sibs). Many Kleinfelter males lead a normal life.
*Very rarely more extreme forms of Kleinfelter's syndrome occurwhere the patient has 48, XXXY or even 49, XXXXY karyotype.These individuals are generally severely handicap.
![Page 21: Genetic Disorders. Overview 6 billion base pairs of DNA ~ 3 meters of DNA Approximately 30,000 – 70,000 genes * Approximately 80-100,000 proteins These.](https://reader030.fdocuments.us/reader030/viewer/2022032702/56649cf15503460f949c037a/html5/thumbnails/21.jpg)
![Page 22: Genetic Disorders. Overview 6 billion base pairs of DNA ~ 3 meters of DNA Approximately 30,000 – 70,000 genes * Approximately 80-100,000 proteins These.](https://reader030.fdocuments.us/reader030/viewer/2022032702/56649cf15503460f949c037a/html5/thumbnails/22.jpg)
XXX Syndrome
![Page 23: Genetic Disorders. Overview 6 billion base pairs of DNA ~ 3 meters of DNA Approximately 30,000 – 70,000 genes * Approximately 80-100,000 proteins These.](https://reader030.fdocuments.us/reader030/viewer/2022032702/56649cf15503460f949c037a/html5/thumbnails/23.jpg)
Triple X syndrome is not inherited, but usually occurs as a random event during the formation of the reproductive cells.
*There may be a growth spurt until the age of approximately eight years of age, resulting in a taller than average final height
*They often have a increased risk of learning disabilities and delayed speech and language skills.
*They have a slightly lower intelligence level than their siblings (the IQ may be ten to fifteen points lower than their siblings).
*Females with this condition are not at any increased risk for medical problems.
XXX Syndrome
![Page 24: Genetic Disorders. Overview 6 billion base pairs of DNA ~ 3 meters of DNA Approximately 30,000 – 70,000 genes * Approximately 80-100,000 proteins These.](https://reader030.fdocuments.us/reader030/viewer/2022032702/56649cf15503460f949c037a/html5/thumbnails/24.jpg)
XYY Syndrome
![Page 25: Genetic Disorders. Overview 6 billion base pairs of DNA ~ 3 meters of DNA Approximately 30,000 – 70,000 genes * Approximately 80-100,000 proteins These.](https://reader030.fdocuments.us/reader030/viewer/2022032702/56649cf15503460f949c037a/html5/thumbnails/25.jpg)
Men who have XYY's syndrome are substantially taller, tend to be wiry-built, and tend to have severe acne.
Minor birth defects -- like pectus, crooked eye, and minor outturning of the elbows, are supposed to be common in XYY's.
![Page 26: Genetic Disorders. Overview 6 billion base pairs of DNA ~ 3 meters of DNA Approximately 30,000 – 70,000 genes * Approximately 80-100,000 proteins These.](https://reader030.fdocuments.us/reader030/viewer/2022032702/56649cf15503460f949c037a/html5/thumbnails/26.jpg)
Color Blindness
![Page 27: Genetic Disorders. Overview 6 billion base pairs of DNA ~ 3 meters of DNA Approximately 30,000 – 70,000 genes * Approximately 80-100,000 proteins These.](https://reader030.fdocuments.us/reader030/viewer/2022032702/56649cf15503460f949c037a/html5/thumbnails/27.jpg)
Colorblindness• 3 human genes
associated with color vision are located on the X chromosome.
• Because males have
one X chromosome, all the genes will be expressed, even if they are recessive.