Download Biology 3201 Chromosomal Mutations Information Table

Chromosomal Mutations
Disorder
(Name or Type)
Deletion
Inversion
Duplication
Translocation
Down Syndrome
Turner Syndrome
Klinefelters Syndrome
Jacobs Syndrome
Triple X Syndrome
Chromosome
Type Involved
Amount of
Genetic Material
Involved
Cause of the Disorder
(Include mutagen or non-disjunction, information from previous columns, and
any other appropriate information)
NA
Several genes or
a portion of the
chromosome
Natural mutagens (viruses), physical mutagens (irradiation), or chemical
mutagens cause a piece of the chromosome to be broken off.
Loss of genes from chromosome 5 causes mental handicap and facial
abnormalities. This includes abnormal larynx and the baby cries like a cat
(Cri-du-cat).
NA
Several genes or
a portion of the
chromosome
Physical or chemical mutagens cause a gene segment to become free from
its chromosome momentarily and it gets reinserted in reverse order.
Some forms of autism are thought to be associated with this event. Children
with this disorder have difficulty communicating or forming relationships.
They may rock back and forth or exhibit other repetitive behaviors.
NA
Several genes or
a portion of the
chromosome
Physical or chemical mutagens cause a gene segment to repeat itself too
many times.
Fragile X chromosome is a well studied example of this problem. See Figure
16.28, p.552
NA
Several genes or
a portion of the
chromosome
Physical or chemical mutagens cause a gene segment to be lost from one
chromosome and become attached to another non-homologous chromosome.
If a section of chromosome 14 is exchanged with a section of chromosome 21 this
might cause Down syndrome. If part of chromosome 14 is exchanged with
chromosome 8 this might cause cancer. If genes from chromosome 22 and 9 get
exchanged this might lead to leukemia.
Whole
chromosome(s)
Nondisjunction (trisomy) of the 21st pair of autosomal chromosomes due to a problem
in meiosis. This can also occur via tranlocation of genetic material from chromosome
14 to chromosome 21. This problem can develop in males or females.
Person has 47 chromosomes in every cell in the body instead of the normal
46. Person is mentally handicapped, short, stocky, thick neck, and thick
tongue (may cause speech problems).
Whole
chromosome(s)
Nondisjunction (monosomy) of the sex chromosomes due to a problem in
meiosis. This can also occur due to a significant amount of chromosomal
deletion of one of the X chromosomes. This problem develops in females.
Person has 45 chromosomes in every cell in the body instead of the normal 46 (ie. only one sex
chromosome – the X chromosome) OR the person has a significant amount of information missing
from one X chromosome in every cell. In this case they will have the normal number of
chromosomes (46) in every cell. Other symptoms include: short with female genitalia but no
ovaries or menstrual period, webbed neck, heart defects, kidney and skeletal abnormalities,
learning difficulty, and thyroid disfunction. Treatments include: Injections of HGH to improve
height and injections of estrogen to begin development of secondary sex characteristics.
Whole
chromosome(s)
Nondisjunction (trisomy) of the sex chromosomes due to a problem in
meiosis. This genotype can occur in males or females but the problem
typically gets manifested in males.
The male has an extra X chromosome (ie. XXY) that produces 47 chromosomes in
every cell in the body. The male may only develop immature sex organs (and be
sterile), be unable to grow facial hair, have breast development. Most have normal
intelligence. Treatments include: hormone therapy and reconstructive therapy.
Whole
chromosome(s)
Nondisjunction (trisomy) of the sex chromosomes due to a problem in
meiosis. This problem develops in males.
All cells in this person will have 47 chromosomes (ie. with XYY). Ninety-six percent of
men with this disorder are normal. The other four percent may develop acne that is
hard to remove (persistent), may be tall, may have speech or reading problems, may
be more aggressive, may be less sympathetic to the feelings of others, and may have
lower mental ability.
Whole
chromosome(s)
Nondisjunction (trisomy) of the sex chromosomes due to a problem in
meiosis. This problem occurs in females.
Person has 47 chromosomes (ie. XXX) in every cell in the body. The person
will have normal intelligence, normal appearance, but may be sterile.
Autosome
Sex
Sex
Sex
Sex
Symptoms of the Disorder
(Include treatments where appropriate to do so)