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Karyotype
Disorder
Edwards
Syndrome
Karyotype
Trisomy 18
47,XX,+18
Or
47,XY,+18
Trisomy 13
47,XX,+13
Or
47,XY,+13
Trisomy 21
47,XX,+21
Or
47,XY,+21
Implications
Mental retardation, failure to thrive, severe
heart defects, micrognathia, malformed ears,
clenched fists w/ overlap. 2nd and 3rd digits,
rocker-bottom feet
Midline defects- holoprosencephaly,
cyclopia, micropthlamia, absence of eyes,
cleft lip and palate, rocker-bottom feet,
congenital <3 and urogen. Defects
Hypotonia, short stature, short neck, flat
nasal bridge, protruding tongue, open
mouth, short broad hands, transverse palmar
crease, IQ= 30-60
-congenital heart defects, leukemia, and
early onset Alzheimers
Viability
*80% are female
*95% aborted spont.
Turner
Syndrome
Monosomy
45,XO,-X
1/ 4000 livebirths
Only viable monosomy
Klinefelter
Syndrome
Trisomy
47,XXY,+X
Often detected at puberty in females
Short stature, webbed neck, shielded chest
with wide-spaced nipples, lymphedema of
hands and feet, gonadal dysgenesis (streak
gonads), primary amenhorrea, infertility,
risk for cardiovasc abnormalities,
intelligence normal
Tall stature, thin and long legs,
hypogonadism, infertility, gynecomastia,
learning difficulties
Patau
Syndrome)
Down
Syndrome
*Infants rarely survive past 1
month
*75-80% spont. Aborted
1/1000 (males)
Chart of common genetic disorders
The following diagram is of a set of human chromosomes. This diagram is known as a KARYOTYPE.
There are several things that can been seen in such a diagram.
Karyotype A
1.
Notice that the chromosomes are paired up. How many pairs of chromosomes do you see?
2. Look carefully at the chromosomes. There are at least 3 characteristics that they are paired up
upon. List the 3
a.
b.
c.
3.
What is the sex of this individual?
4. What do you think the regions of the light and dark bands are?
5. If you start at chromosome 1 and work to chromosome 22 there is a trend in size. What is this
trend?
6. How do you think this trend (question 5) affects the amount of genetic information on each of
the chromosomes?
7. How many pairs of NUMBERED chromosomes are there?
8. What are the NUMBERED chromosomes called?
9. There is a final set of paired chromosomes, these are called SEX CHROMOSOMES. What are the
combination possibilities for the sex chromosomes
10. Every karyotype is specially named. This naming system is based on three things.
a. The number of chromosomes (example: 46)
b. The sex of the individual (example: female)
c. Any extra chromosomes that would cause a genetic defect (example: trisomy 18)
11. What would you name this particular karyotype?
_______________________ ______________________ ___________________
Karyotype B
1. How many pairs of autosomes does this karyotype have?
2. How many pairs of sex chromosomes does this karyotype have?
3. What is the sex of this individual?
4. Are there any TRISOMY’S (three chromosomes instead of a pair) in this karyotype?
5.
What is the technical name of this disorder?
6. What is the common name of this disorder?
7. What will you name this karyotype?
_______________________ ______________________ ___________________
Karyotype C
1. What is the sex of this individual?
2. Are there any TRISOMY’S?
3. Name this karyotype
_______________________ ______________________ ___________________
Karyotype D
1. How many chromosomes are in this individual?
2. Are there any MONOSOMIES (only one chromosome, not a pair) present?
3. What is the genotype for the sex of this individual?
4. What is the name of this disorder?
5. What is the name of this karyotype
_______________________ ______________________ ___________________
Karyotype E
1. What is the sex of this individual?
2. What would you name this karyotype?
_______________________ ______________________ ___________________
Pedigree
What is the symbol for each of the following?
Not affected male=
Not affected female=
Affected male=
Affected female=
Carrier female=
(Sex-linked only)
Pedigree 1: The following pedigree shows a family affected by red-green color blindness, which
is an sex-linked trait (Xb)
1. What are the genotypes of the following individuals?
2. Shade in half of the circle for the carriers.
A__________________________ B________________________ C________________
Pedigree 2: The following pedigree shows a family that has freckles, which is an autosomal
dominant trait (F). An individual without freckles has the recessive trait. Individuals with
freckles are shaded in.
1. What are the genotypes of the following individuals?
I-1 ____________________ II-2_________________ III-2
2. If individual II-2 marries a man who does not have freckles, what is the chance that their
children will have freckles?
Pedigree 3. The following pedigree represents a family in which some individuals are affected
with Hemophilia, a sex-linked disease (XH).
1. Label the genotypes of all the individuals in the pedigree
2. If a female is a carrier, fill in half of the circle.
3. If a female’s genotype is unknown, label the circle with a “U”
Use the above pedigree to answer questions 1-5
1. How many males have hemophilia?
1. How many females have hemophilia?
2. How many children did the first couple (I) have?
3. How many children did the third couple (III) have?
4. If the first male in generation IV marries a woman who is a carrier for the Hemophilia
allele, what is the chance that their son will have hemophilia?
Pedigree 4. The following pedigree shows a family affected by Huntington’s disease. Shaded
individuals have Huntington’s disease, which is an Autosomal Dominant disorder (HH or Hh),
individuals not shaded are recessive and normal for the Huntington’s allele (hh).
Label all of the individual genotypes
1. How many children did individuals I-1 and I-2 have?
2. How many girls did II-1 and II-2 have? How many have Huntington’s disease?
3. How is individual III-2 and II-4 related?
4. How is individual I-2 and III-5 related?
5. If individual III-5 marries a heterozygous woman, what is the chance that their children
could have Huntington’s disease?