NU 545 Test -QUESTIONS WITH ALL
CORRECT ANSWERS!!
Describe the specific chromosomal abnormality responsible for Down Syndrome
The most well known aneuploidy (those that do not contain a multiple of 23 chromosomes) in an
autosome is trisomy of the 21st chromosome. J. Langdon Down 1st described the the disease in
1866. Down syndrome is seen in 1 in 800 births. IQ's between 25 and 70. Facial features: low
nasal bridge, epicentral folds, protruding tongue, and flat low set ears. Congenital heart defects in
1/3 to 1/2 of live born children. Decreased ability to fight respiratory conditions and an increased
susceptibility to leukemia. By age 40 symptoms resembling Alzheimer develop. 97% of Down
Syndrome's cases are caused by nondisjunction during the formation of one of the parent's
gametes or during early embryonic development. 3% from translocations. Risk increases with
maternal age.
Causes of mental retardation.
Chromosomal abnormalities.
What gene abnormality causes cystic fibrosis?
Like autosomal dominant diseases, those caused by autosomal recessive alleles are rare in
populations, although the number of carriers for recessive diseases can be high. The most
common lethal recessive disease in white children, cystic fibrosis, occurs in about 1 in 2500
births. Approximately 1 in 25 whites carries one copy of an allele that can cause cystic fibrosis
(see Chapter 36). Because an individual must be homozygous for a recessive allele to express
thedisease, the carriers are phenotypically normal. Because most recessive alleles are maintained
innormal carriers, they are able to survive in the population from one generation to the next. As
,with many autosomal dominant diseases, many autosomal recessive diseases are characterized by
delayed age of onset, incomplete penetrance, and variable expressivity.
How is a recessive gene inherited?
Autosomal recessive diseases occur when both parents are carriers of the same disease and their
child inherits an altered gene from each of them. Children of carrier parents have:A 25% chance
of inheriting two altered genes and developing the disease.
Inheritance of Hemophilia A?
Hemophilia A and hemophilia B are inherited in an X-linked recessive pattern. The genes
associated with these conditions are located on the X chromosome, which is one of the two sex
chromosomes. In males (who have only one X chromosome), one altered copy of the gene in
each cell is sufficient to cause the condition. In females (who have two X chromosomes), a
mutation would have to occur in both copies of the gene to cause the disorder. Because it is
unlikely that females will have two altered copies of this gene, it is very rare for females to have
hemophilia. A characteristic of X-linked inheritance is that fathers cannot pass X-linked traits to
their sons.
In X-linked recessive inheritance, a female with one altered copy of the gene in each cell is
called a carrier. Carrier females have about half the usual amount of coagulation factor VIII or
coagulation factor IX, which is generally enough for normal blood clotting. However, about 10
percent of carrier females have less than half the normal amount of one of these coagulation
factors; these individuals are at risk for abnormal bleeding, particularly after an injury, surgery,
or tooth extraction.
,Risk factors for DM II; why is obesity an important risk factor for DM II?
An important risk factor is TCF7L2 which encodes a transcription factor involved in the
secretion of insulin. Another association has been found between a common allele of the gene
that incomes peroxisome proliferator-activated receptor gamma (PPAR-y), a nuclear receptor
that is involved in adipocyte differentiation and glucose metabolism. This receptor is the target
of thiazolidinediones (TZD's) a class of drugs commonly used to increase insulin sensitivity in
those with type 2 diabetes. The 2 most important risk factors for DM II are positive family
history and obesity; the latter increases insulin resistance.
Definition of carcinoma
Cancer arising from in epithelial cells
How do cancer cells gain access to the circulation?
cells gain access to circulation through new tumor-associated blood vessels or angiongesis
Mobile tumor cells are able to enter circulation (leakly newsly made blood vessels)
once in circulation, cells must be able to withstand the physiological stress of travel in the blood
and lymphatic circulation
Sometimes they bind to blood platelets=protect themselves
What is adjuvant chemotherapy?
Adjuvant chemotherapy is an approach to fighting cancer that combines different forms of
healing. Chemotherapy and radiation, or chemotherapy and surgery are used together. Usually
the chemotherapy will be used after all of the known and visible cancer has been removed
surgically or with radiation. Adjuvant chemotherapy aims to destroy hidden cancer cells that
, remain but are undetectable.
Adjuvant means additional. Adjuvant chemotherapy is given to patients after primary treatment,
when the doctor thinks there is a high risk the cancer will return. After a primary treatment of
surgery or radiation, adjuvant chemotherapy reduces the risk of recurrence. The elimination of
undetectable microscopic cancer cells that may have traveled to other parts of the body is the
goal of adjuvant chemotherapy.
When adjuvant chemotherapy doesn't result in a full cure it does make the intervals between a
cancer relapse longer. Adjuvant chemotherapy typically begins within three to five weeks of the
surgical removal of the cancer and has different treatment lengths depending on the cancer. For
breast cancer, the adjuvant chemotherapy is administered for three to nine months. In the case of
colon cancer, treatment rarely last more than six months.
Most common time childhood cancers are diagnosed?
Childhood and adolescent cancers are often associated with specific peak times of physical
growth and may occur as a consequence altered cellular regulatory mechanisms at a given time
in the child or adolescents development. Embryonal tumors most often develop before the age of
5 years, acute lymphoblastic leukemia occurs most often in younger children, and bone tumors
occur most often in adolescents.
DES exposure prenatally
CORRECT ANSWERS!!
Describe the specific chromosomal abnormality responsible for Down Syndrome
The most well known aneuploidy (those that do not contain a multiple of 23 chromosomes) in an
autosome is trisomy of the 21st chromosome. J. Langdon Down 1st described the the disease in
1866. Down syndrome is seen in 1 in 800 births. IQ's between 25 and 70. Facial features: low
nasal bridge, epicentral folds, protruding tongue, and flat low set ears. Congenital heart defects in
1/3 to 1/2 of live born children. Decreased ability to fight respiratory conditions and an increased
susceptibility to leukemia. By age 40 symptoms resembling Alzheimer develop. 97% of Down
Syndrome's cases are caused by nondisjunction during the formation of one of the parent's
gametes or during early embryonic development. 3% from translocations. Risk increases with
maternal age.
Causes of mental retardation.
Chromosomal abnormalities.
What gene abnormality causes cystic fibrosis?
Like autosomal dominant diseases, those caused by autosomal recessive alleles are rare in
populations, although the number of carriers for recessive diseases can be high. The most
common lethal recessive disease in white children, cystic fibrosis, occurs in about 1 in 2500
births. Approximately 1 in 25 whites carries one copy of an allele that can cause cystic fibrosis
(see Chapter 36). Because an individual must be homozygous for a recessive allele to express
thedisease, the carriers are phenotypically normal. Because most recessive alleles are maintained
innormal carriers, they are able to survive in the population from one generation to the next. As
,with many autosomal dominant diseases, many autosomal recessive diseases are characterized by
delayed age of onset, incomplete penetrance, and variable expressivity.
How is a recessive gene inherited?
Autosomal recessive diseases occur when both parents are carriers of the same disease and their
child inherits an altered gene from each of them. Children of carrier parents have:A 25% chance
of inheriting two altered genes and developing the disease.
Inheritance of Hemophilia A?
Hemophilia A and hemophilia B are inherited in an X-linked recessive pattern. The genes
associated with these conditions are located on the X chromosome, which is one of the two sex
chromosomes. In males (who have only one X chromosome), one altered copy of the gene in
each cell is sufficient to cause the condition. In females (who have two X chromosomes), a
mutation would have to occur in both copies of the gene to cause the disorder. Because it is
unlikely that females will have two altered copies of this gene, it is very rare for females to have
hemophilia. A characteristic of X-linked inheritance is that fathers cannot pass X-linked traits to
their sons.
In X-linked recessive inheritance, a female with one altered copy of the gene in each cell is
called a carrier. Carrier females have about half the usual amount of coagulation factor VIII or
coagulation factor IX, which is generally enough for normal blood clotting. However, about 10
percent of carrier females have less than half the normal amount of one of these coagulation
factors; these individuals are at risk for abnormal bleeding, particularly after an injury, surgery,
or tooth extraction.
,Risk factors for DM II; why is obesity an important risk factor for DM II?
An important risk factor is TCF7L2 which encodes a transcription factor involved in the
secretion of insulin. Another association has been found between a common allele of the gene
that incomes peroxisome proliferator-activated receptor gamma (PPAR-y), a nuclear receptor
that is involved in adipocyte differentiation and glucose metabolism. This receptor is the target
of thiazolidinediones (TZD's) a class of drugs commonly used to increase insulin sensitivity in
those with type 2 diabetes. The 2 most important risk factors for DM II are positive family
history and obesity; the latter increases insulin resistance.
Definition of carcinoma
Cancer arising from in epithelial cells
How do cancer cells gain access to the circulation?
cells gain access to circulation through new tumor-associated blood vessels or angiongesis
Mobile tumor cells are able to enter circulation (leakly newsly made blood vessels)
once in circulation, cells must be able to withstand the physiological stress of travel in the blood
and lymphatic circulation
Sometimes they bind to blood platelets=protect themselves
What is adjuvant chemotherapy?
Adjuvant chemotherapy is an approach to fighting cancer that combines different forms of
healing. Chemotherapy and radiation, or chemotherapy and surgery are used together. Usually
the chemotherapy will be used after all of the known and visible cancer has been removed
surgically or with radiation. Adjuvant chemotherapy aims to destroy hidden cancer cells that
, remain but are undetectable.
Adjuvant means additional. Adjuvant chemotherapy is given to patients after primary treatment,
when the doctor thinks there is a high risk the cancer will return. After a primary treatment of
surgery or radiation, adjuvant chemotherapy reduces the risk of recurrence. The elimination of
undetectable microscopic cancer cells that may have traveled to other parts of the body is the
goal of adjuvant chemotherapy.
When adjuvant chemotherapy doesn't result in a full cure it does make the intervals between a
cancer relapse longer. Adjuvant chemotherapy typically begins within three to five weeks of the
surgical removal of the cancer and has different treatment lengths depending on the cancer. For
breast cancer, the adjuvant chemotherapy is administered for three to nine months. In the case of
colon cancer, treatment rarely last more than six months.
Most common time childhood cancers are diagnosed?
Childhood and adolescent cancers are often associated with specific peak times of physical
growth and may occur as a consequence altered cellular regulatory mechanisms at a given time
in the child or adolescents development. Embryonal tumors most often develop before the age of
5 years, acute lymphoblastic leukemia occurs most often in younger children, and bone tumors
occur most often in adolescents.
DES exposure prenatally
