Pathpharm 2 week 2 Flashcards
One gene may “mask” another gene when the 2 are found together on a heterozygote. This refers to:
The principle of dominance.
The______________ gene’s characteristics are observable
“dominant”
The concealed gene is called_________
“recessive”
Genes for a ____________ disease occur in heterozygotes who carry 1 copy of the gene, but do not express the disease
“recessive”
What are some Injurois Genetic Factors that can lead to disease?
Nuclear alterations, Alterations in the plasma membrane structure, shape, receptors, or transport mechanisms
Sickle cell anemia and muscular dystrophy are examples of diseases caused by:
injurious genetic factors
_________________ result from a deficiency, excess, or structural abnormality in a chromosome.
Chromosomal disorders
Aneuploidy is a common chromosomal disorder resulting from:
an extra chromosome or a missing chromosome
Structural abnormalities involve:
loss (deletion) or excess (duplication) of part of a chromosome
What are two examples of chromosomal disorders?
Down’s syndrome, Cri du Chat
Trisomy 21 will cause which disease?
Down’s Syndrome
______________ occurs when some cells have 3 copies of chromosome 21, but others do not.
Mosaic Down’s syndrome
____________ occurs when nearly all or part of a chromosome 21 becomes attached to another chromosome in the cell
Translocation Down’s Syndrome
T or F: Translocation Down’s syndrome is inheritable.
TRUE
___________ results when a piece of chromosome 5 is missing.
Cri-du-chat
Infants with Cri-du-chat often have:
a high-pitched cry that sounds like a cat
T or F: No matter what the size of the deletion on chromosome 5 the effects on the person will be the same.
FALSE. Studies suggest the larger the deletion the more severe retardation will occur.
____________________________ disorders occur when a mutation is present in one copy of a gene carried on an autosome.
Autosomal dominant disorders
Children of a person with an autosomal dominant disorder have a __________ chance of inheriting the mutation
50.00%
T or F: In respect to autosomal dominant disorders- Males and females are equally likely to inherit the mutation and to be affected
TRUE
In this type of disorder Family history typically reveals the disorder in sequential generations
autosomal dominant disorders
What are two examples of Autosomal Dominant Disorders?
Huntington’s disease, Neurofibromatosis
____________ is a progressive brain disorder that causes uncontrolled movements, mental and emotional problems, and loss of thinking abilit
Huntington’s disease
________________ occur when two mutations — one in each gene, for a gene on an autosome — are necessary to cause disease.
autosomal recessive disorders
______________(such as parents of an affected individual) carry one copy of the mutated gene, are asymptomatic, and are considered carriers.
Heterozygotes
If two carriers have children, each child has what odds of inheriting normal or affected genes?
25% chance of inheriting both mutations and having the disease, a 50% chance of one mutation and being an unaffected carrier, and a 25% chance of inheriting both normal alleles.
Sickle Cell anemia, Cystic Fibrosis are both examples of:
Autosomal Recessive Disorders
Cystic firbrosis results from:
abnormal sodium transport leading to airway and pancreatic duct obstruction
T or F: In autosomal recessive defects, only one parent needs to donate a defective gene.
FALSE. BOTH parents must donate the defective gene
________________________ are present when a mutation occurs in a gene on the X chromosome
X linked Recessive Disorder
In this type of disorder a single mutation is sufficient to cause disease in a male; women with a single mutation are heterozygotes and are considered carriers.
X linked Recessive Disorder
T or F: Carriers of X-linked recessive disorders may be asymptomatic or symptomatic, depending on the level of X-chromosome inactivation in relevant tissues.
TRUE
Sons of carriers have a________ risk of being affected; daughters of carriers have a _______ risk of being carriers
50% ;50%
What is gene therapy?
Gene therapy is a technique for correcting defective genes responsible for disease development.
What is the most common method that researchers use in gene therapy?
A normal gene may be inserted into a nonspecific location within the genome to replace a nonfunctional gene.
An abnormal gene could be swapped for a normal gene through homologous recombination, The abnormal gene could be repaired through selective reverse mutation, which returns the gene to its normal function, and The regulation (the degree to which a gene is turned on or off) of a particular gene could be altered are all examples of:
gene therapy
What are genes?
specific sequences of bases that encode instructions on how to make proteins.
T or F: Genes perform most life functions and even make up the majority of cellular structures.
FALSE. PROTIENS perform most life functions and even make up the majority of cellular structures.
In most gene therapy studies what occurs?
a “normal” gene is inserted into the genome to replace an “abnormal,” disease-causing gene.
A carrier molecule called a ________ must be used to deliver the therapeutic gene to the patient’s target cells.
vector
What is the most common vector in gene therapy today?
a virus that has been genetically altered to carry normal human DNA.
T or F: The Herpes simplex virus is used in gene therapy.
TRUE
What 4 main factors have kept gene therapy from becoming and effective treatment for genetic disease?
Negative immune responses: Anytime a foreign object is introduced into human tissues the immune system is designed to attack the invader; problems with viral vectors: toxicity, immune and inflammatory responses, gene control and targeting issues, and fear that the viral vector may recover its ability to cause disease; short-lived nature of gene therapy: Patients will have to undergo multiple rounds of gene therapy., and multigene disorders:Multigene or multifactorial disorders would be especially difficult to treat effectively using gene therapy
_____________ have the remarkable potential to develop into many different cell types in the body during early life and growth
stem cells
Stem cells are distinguished from other cell types by which two important characteristics?
- unspecialized cells capable of renewing themselves through cell division, 2. under certain physiologic or experimental conditions, they can be induced to become tissue- or organ-specific cells with special functions
T or F: In the heart, gut, and bone marrow stem cells regularly divide to repair and replace worn out or damaged tissues.
FALSE. Stem cells regularily divide in the gut and bone marrow, but they only divide in the heart and pancreas under special conditions.
______________ is a chromosomal condition that is associated with mental retardation, a characteristic facial appearance, and poor muscle tone (hypotonia) in infancy. People with this condition are at an increased risk for heart defects, digestive problems such as gastroesophageal reflux or celiac disease, hearing loss, and cancer of blood-forming tissue (leukemia). Additionally, some people have reduced activity of the thyroid gland (hypothyroidism).
Down syndrome
_____________ is also known as “5p-“ syndrome because it results from a deletion of the short (p) arm of chromosome 5
cri-du-chat
This disorder is characterized by mental retardation and delayed development, distinctive facial features, small head size (microcephaly), low birth weight, and weak muscle tone (hypotonia) in infancy.
Cri-du-chat
T or F: Cri-du-chat syndrome is inheritable.
FALSE. It is a random event.
Early signs and symptoms of this disease can include irritability, depression, small involuntary movements, poor coordination, and trouble learning new information or making decisions.
Huntington’s syndrome
Mutations in the______ gene cause Huntington disease.
HD
this inherited disorder causes progressive damage to the respiratory system and chronic digestive system problems
cystic fibrosis
Mutations in the CFTR gene cause_________
cystic fibrosis
Hemophilia is a___________ disorder
x-linked recessive
____________is a disorder that affects coagulation
Hemophilia
People with __________ hemophilia experience episodes of excessive bleeding in childhood, but have few bleeding problems after puberty.
hemophilia B Leyden
____________ is a genetic disorder caused by a missing or incomplete X chromosome. Girls who have it are short, their ovaries don’t work properly, and most are infertile. They are at risk for health difficulties such as high blood pressure, kidney problems, diabetes, cataracts, osteoporosis and thyroid problems.
Turner syndrome
Physical features of Turner’s syndrome include:
Short, “webbed” neck with folds of skin from tops of shoulders to sides of neck, Low hairline in the back, Low-set ears, and Swollen hands and feet
Males with a chromosomal make-up of 47,XXY is associated with which syndrome?
Klinefelter syndrome
Why is the shortage of testosterone that occurs with Klinefelter syndrome an issue?
It can lead to delayed or incomplete puberty, breast enlargement (gynecomastia), reduced facial and body hair, and an inability to have biological children (infertility). Some affected individuals may have undescended testes (cryptorchidism), the opening of the urethra on the underside of the penis (hypospadias), or an unusually small penis (micropenis).
________________ is a genetic disorder that mainly affects how nerve cells form and grow by causing tumors to grow on nerves.
Neurofibromatosis
What are the three types of Neurofibromatosis?
Type 1 (NF1), Type 2 (NF2), and Schwannomatosis
This type of Neurofibromatosis usually starts in childhood, can be present at birth, and causes skin changes and deformed bones.
Type 1
Type 2 (NF2) causes:________________ and symptoms often start_____________
hearing loss, ringing in the ears, and poor balance; in the teen years.
Schwannomatosis causes___________, and it is the (most common/rarest) type.
intense pain; rarest
T or F: Both boys and girls can exhibit Duchenne muscular dystrophy
FALSE. Because of the way it is inherited only boys will get the disease, but girls will be carriers.
What is gene mapping?
mapping genes to a specific location on a chromosome.
Why is gene mapping helpful for researchers?
Gene mapping assists researchers in finding the location of a mutation so they can fix it more efficiently.
Define Oncogenes:
mutant genes; in their normal non-mutant state direct synthesis of proteins that positively regulate proliferation. Once mutated proliferation becomes unchecked
What is the purpose of Tumor suppressor genes?
Encode proteins that in their normal state negatively regulate proliferation (suppress tumor growth)
What type of gene is sometimes referred to as an “anti-oncogene”?
Tumor suppressor gene
What is a Proto-oncogene?
A normal, nonmutant gene that codes for cellular growth
This cancer treatment is used to stop metastasis, used when surgery is not an option (difficult to reach places)
radiation
Some cons of radiation are:
side effects include nausea, vomiting, diarrhea, fatigue and skin redness and irritation at the site of the therapy; death of skin tissue (atrophy), skin pain and/or itching and greater vulnerability to infection.
This type of cancer treatment is effective in removing single masses; surgeon specifically targets cancer cells
surgery
What are some cons of surgery as a cancer treatment?
cons: not effective in treating metastasized cancers; risk for bleeding and infection post-op
This type of cancer treatment has the pro: can be administered in an outpatient setting
chemotherapy
What are some cons to chemotherapy?
harmful to all cells, not just cancer cells; fatigue, nausea/vomiting, dizzy, hair loss, reduced blood counts, immunosuppression and increased infection risk. Long term effects include infertility and damage to the heart, lungs and kidneys.
