Genetics Diseases Exam 1

The disease, named severe acute respiratory syndrome (SARS), is spread by _______ produced when an infected person ________

droplets

sneezes or coughs

How is the DNA vaccines being developed for SARS

To make a DNA vaccine, one of the virus’s genes was isolated using recombinant DNA technology. The viral gene was injected into mice, where it directed the synthesis of a viral protein. The mouse’s immune system responded by making antibodies against the protein, which protected the mouse against future infections with the SARS virus.

What did the actual COVID vaccine inject ?

Viral RNA

SARS (symptoms, inheritance, molecular, fun facts)

Symptoms: cold and flu like symptoms

Inheritance: no inheritance (virus)

Molecular: no molecular

Fun Facts: DNA vaccines are being developed

Creutzfeldt-Jacob Disease (symptoms, inheritance, molecular, fun facts)

Symptoms: Human form of mad cow disease, memory loss —> death

• Cow food doesn’t have enough amino acids or proteins so leftover parts of dead cows are added to food and they eat it so when we eat an infected cow humans can get it

Inheritance: None (prions acquired by eating contaminated meat)

Molecular: Prions are abnormally folded proteins

Fun Facts: Disease and infection transmitted without DNA

Alkaptonuria (symptoms, inheritance, molecular, fun facts)

Symptoms: Black urine due to accumulation of alkapton

Inheritance: none

Molecular: The gene responsible for the enzyme breaking down alkapton is mutated

Fun Fact: Helped establish the link between genes and proteins

Cystic Fibrosis (symptoms, inheritance, molecular, fun fact)

Symptoms:

Inheritance:

Molecular: Deletion of a single amino acid. Makes chloride ion membrane channel fold wrongly.

• glands have thick mucus excretion instead of liquid

Fun Fact:

The disease takes _______ to develop, and _____ people are more likely to develop vCJD than are the _____.

years, young people, the elderly

People can get vCJD by eating meat from cows infected with a brain-wasting disease called ____________

bovine spongiform encephalopathy (BSE)

Prions are created when normal proteins in the body refold into a different and infectious three-dimensional shape that kills cells of the _____ and ________.

brain and nervous system

Archibald Garrod proposed the existence of a relationship among genes, proteins, and phenotypes, based on his studies of infants with a condition called _______

alkaptonuria

Newborns with alkaptonuria have urine that turns _____ when exposed to _____

black when exposed to air

From family histories, Garrod observed that the phenotype of this disorder followed a _____ pattern of inheritance, leading him to conclude that a defective gene was the underlying cause of alkaptonuria.

recessive

The most common mutation in cystic fibrosis is a deletion of the amino acid _____ at amino acid number _____.

phenylalanine at amino acid number 508

This single amino acid change causes the polypeptide to fold improperly inside the ____. The misfolded CFTR is identified as defective and destroyed in the RER; as a result, it does not reach the ________. The phenotype of cystic fibrosis is produced because there is no _______ in the plasma membrane to regulate the flow of chloride ions.

RER, plasma membrane, CFTR protein

Protein refolding diseases are called _____ diseases

prion

Hemophilia (symptoms, inheritance, molecular, fun facts)

Symptoms: Bleeding defects with blood clotting

Inheritance: X-linked recessive

Fun Facts

• One of the parents of Queen Victoria is the one most likely to have received the mutation (her daughters were married with one going to Russia and bringing the mutation there)

• Recombinant technology have made cheap and safe blood clotting factors available

The X-linked form of hemophilia that spread through the royal families of western Europe and Russia in the nineteenth and twentieth centuries probably originated with ______

Queen Victoria

None of the males in previous generations of her family had hemophilia, but one of Victoria’s sons was _____, and at least two of her daughters were ______.

affected

heterozygous carriers

Achindroplasia (symptoms, inheritance, molecular, fun facts)

Symptoms: A form of dwarfism producing short arms, legs, and an elongated skull

Inheritance: Dominant

Fun Fact: Mutation rate is 1.4×10^-5 (very fast mutation rate)

Neurofibromatosis (symptoms, inheritance, molecular, fun facts)

Pigmentation spots and tumors of skin and nervous system

Autosomal dominant

Mutation rate 1.4×10^-4

Huntington Disease (symptoms, inheritance, molecular, fun facts)

Progressive degeneration of the nervous system

Autosomal Dominant

Mutation rate is 1.4×10^-6

Sickle Cell Anemia (symptoms, inheritance, molecular, fun facts)

Anemia and sickle shaped red blood cells

Recessive

Beta-globin gene has a six change from glu to val (GAG —> GUG)

• produces fibers that makes cells stick together

An example of a missense mutation with a large phenotypic effect

Hemoglobin C disease (symptoms, inheritance, molecular, fun facts)

Mild anemia, less serious than sickle cell anemia

Recessive

Beta-globin gene has a six change from glu to lys (GAG —> AAG)

An example of missense mutation that has little phenotypic effect

Beta thalassemia (symptoms, inheritance, molecular, fun facts)

Serious anemia, even fatal

Nucleotide substitution creates a UAG stop codon producing a truncated mRNA

An example of nonsense mutation

Fragile X (symptoms, inheritance, molecular, fun facts)

Mental retardation and other genetic disorders

An X chromosome that carries a nonstaining gap, or break

Region susceptible to break, producing chromosome fragments, deletions, etc

• due to trinucleotide repeats

Allelic expansion is associated with trinucleotide repeats. Anticipation is an associated phenomenon

Xeroderma pigmentosum (symptoms, inheritance, molecular, fun facts)

Extremely sensitive to the sun. Skin cancer enhanced

Autosomal recessive

Mutated genes are involved in DNA repair

Mutation rates directly relate to cancer likelihood. When DNA repair is inactive, effective mutation rates increase

Prader-Willi syndrome & Angelman syndrome (symptoms, inheritance, molecular, fun facts)

Genomic imprinting is associated with this disease

• histone modifications and methylation are eliminated in gametes

Small deletion in chromosome 15

PWS is a genetic mirror image of AS. When the paternal copy is missing, PWS develops. If the maternal copy is missing, AS develops

Crohns Disease (symptoms, inheritance, molecular, fun facts)

Inflamatory bowel disease

NOD2 gene codes for a receptor found on certain immune system cells that recognizes invading bacteria
and activates inflammatory response. Mutant form causes abnormal inflammatory response

Crohns only causes predisposition. In the last 50 years disease has increased greatly, presumably as a result
of unknown environmental factors

Hemolytic disease of the newborn (symptoms, inheritance, molecular, fun facts)

Rh- Mother (makes anti-Rh+ antibodies) rejects fetus that are Rh+

Mother Rh- with multiple offspring Rh+

Mother produces antibodies against fetus

• the placenta protects the initial Rh+ baby from the mothers antibodies but upon birth the mother is exposed to much more Rh+ blood causing her to make many anti- Rh antibodies

• For the second baby she now has many memory cells from the first baby that even though the placenta protects the baby there are small leaks causing the baby to be exposed to the army of attacking antibodies. When the birth occurs the blood mingles exposing even MORE Rh+ blood causing it to be worse for any other babies

Mingling of fetal blood with that of mother commonly occurs during birth, and so the first Rh+ child often is not
affected. However, in response to the presence of the Rh antigen, the mother makes antibodies and subsequent child evoke response.

X-linked agammaglobulinemia (symptoms, inheritance, molecular, fun facts)

Lack mature B cells

Gene controls maturation of B cells

Severe combined immunodeficiency (symptoms, inheritance, molecular, fun facts)

Boy in the bubble had this condition

Both B and T cells are missing

Acquired immunodeficiency syndrome (AIDS) (symptoms, inheritance, molecular, fun facts)

T4 cells gradually decrease

Caused by the HIV virus

RNA is the genetic material

Use condoms

The painting Las Meninas by Diego Velasquez shows Infanta Margarita of the seventeenth-century Spanish court accompanied by her maids and others, including a woman with ________

achondroplasia

The mutation in sickle cell anemia affects the ________ component of hemoglobin

beta globin

This truncated mRNA is not functional, reducing the production of beta globin and causing a serious disorder called _______

beta thalassemia

In the normal allele of the fragile-X gene (MIM 309550), a ___ sequence is present in ____ copies. Mutant copies can carry more than _____ copies, and it appears that trinucleotide repeats may predispose genes to higher rates of mutation.

CGG

6-50

230

If both copies of chromosome 15 are inherited from the mother, the child will have _______; if both copies of chromosome 15 are inherited from the father, the child will have __________.

Prader-Willi syndrome

Angelman syndrome

Crohn disease occurs with a frequency of ______ individuals—mostly young adults.

1 in 1000

The frequency of Crohns has increased greatly over the last 50 years, presumably as a result of ______________.

unknown environmental factors

A genetic predisposition to Crohn disease maps to chromosome _____.

16

In Crohn disease, the protein encoded by the mutant allele is defective and causes an ________ that damages the intestinal wall.

abnormal inflammatory response

If Rh+ blood from the fetus enters the Rh- maternal circulation (this often happens during the birth process), the mother’s immune system will produce antibodies _____ the Rh antigen

against

This heritable disorder, called X-linked agammaglobulinemia (XLA; MIM 300300), usually appears ______ months after birth, when maternal antibodies _____ and the infant’s ___ cell population begins to produce antibodies.

5-6

disappear

B cell

A rare genetic disorder of the immune system causes a complete absence of both antibody-mediated and cell-mediated immune responses.

Severe combined immunodeficiency disease

David, the “boy in the bubble,” had severe combined immunodeficiency and lived in isolation for ____. He died of complications after a _______.

12 years

bone marrow transplant

AIDS is a ________ that develop after infection with the human immunodeficiency virus (HIV)

collection of disorders