T/F: Hemochromatosis is the most frequent hemoglobinopathy
False
Sickle cell anemia is the most frequent hemoglobinopathy
Sickle cell disease is inherited in a(n) ______________ pattern.
a) autosomal dominant
b) autosomal recessive
c) x-linked
d) mitochondrial inheritance
b) autosomal recessive
When offspring inherit both defective genes (HOMOZYGOUS expression), the result is Sickle Cell Disease
Unaffected carriers of sickle cell are said to have sickle cell "trait." This patient is exhibiting _______________ expression for sickle cell.
a) homozygous
b) heterozygous
b) heterozygous
A single hemoglobin molecule can bind ___ molecule(s) of oxygen.
a) 1
b) 2
c) 3
d) 4
d) 4
One molecule of hemoglobin (Hb) has 4 globin chains (tetramer). Each globin chain binds a single heme molecule. Each heme molecule can bind 1 oxygen molecule. Therefore, Hemoglobin can have 4 O2 binding sites.
T/F: Hemoglobin only carries oxygen through the blood.
False
Hemoglobin functions in O2 and CO2 transport
Sickle cell anemia results from a point mutation (missense mutation) resulting in a substitution of a normal amino acid in the chain. Specifically, HbS is a Glutamate to _______________ substitution at residue 6 of beta-globin chains.
a) histidine
b) prol
d) valine
T/F: Sickle cell disease significantly changes the protein, Hemoglobin A to Hemoglobin S, and drastically alters how this protein transports oxygen in the blood.
False
It does change HbA to HbS; however, it does NOT alter how this protein transports oxygen in the blood.
Hemoglobin S is more common among persons whose ancestry is geographically connected to all of the following, except?
a) sub-Saharan Africa
b) South America
c) Central America (+ Cuba)
d) Saudi Arabia
e) East Asia
f) India
g) Mediterranean regions
e) East Asia
Heterozygous expression of HbS results in decreased risk of infection by which of the following parasites?
a) Plasmodium malariae
b) Plasmodium vivax
c) Plasmodium ovale
d) Plasmodium falciparum
d) Plasmodium falciparum
The "heterozygote advantage" is likely due to the clearance of sickled cells by the __________________.
a) liver
b) spleen
c) kidneys
d) GI tract
b) spleen
Clearance of sickled cells by the spleen may explain the protective effect against P. falciparum. Parasites lower the pH which promotes sickling. Clearance of infected cells disrupts the parasite's life cycle
Which of the following is not a method of testing/screening for sickle cell anemia?
a) Hemoglobin solubility test
b) Hemoglobin electrophoresis
c) CBC
d) Serum immunoglobulin levels
e) Family history
f) Newborn screening
d) Serum immunoglobulin levels
- Family history of sickle cell disease or parents of proband to be known carriers
- Complete blood count (CBC): normocytic anemia with target cells. When hypoxemia is present, sickled cells are also reported
Non-sickling beta hemoglobin disorders such as ___________________ can interact with a sickle cell disease mutation to cause clinically significant disease.
a) aplastic anemia
b) Thalassemia
c) iron deficiency anemia
b) Thalassemia
Management of sickle cell disease largely consists of altering the patients environment in which of the following ways?
a) Avoid dehydration
b) Avoid change in altitude
c) Avoid extreme temperatures
d) Prevention of infection
e) Avoid physical stress
ALL OF THEM!
Hereditary Hemochromatosis (HH) is characterized by too much absorption of which common mineral?
a) zinc
b) magnesium
c) iron
d) potassium
c) iron
Toxic accumulation of iron happens particularly in 3 organs. Which of the following are not one of those 3 organs? (select all that apply)
a) heart
b) pancreas
c) spleen
d) kidneys
e) liver
c) spleen
d) kidneys
Too much iron is absorbed, causing its toxic accumulation in parenchymal cells, particularly of the liver, heart and pancreas
Which of the following are clinical hallmarks of advanced HH? (select all that apply)
a) skin pigmentation
b) nephrotoxicity
c) cirrhosis
d) splenomegaly
e) diabetes
f) cardiac failure
a) skin pigmentation
c) cirrhosis
e) diabetes
f) cardiac failure
Hereditary Hemochromatosis (HH) is inherited in a(n) ______________ pattern.
a) autosomal dominant
b) autosomal recessive
c) x-linked
d) mitochondrial inheritance
b) autosomal recessive
T/F: HH typically presents at age 40 years or older.
True
T/F: HH is more common in females than males.
False
10 times more common in males than in females
Hereditary hemochromatosis (type 1 HH) is caused by a single mutation in which gene?
a) APC gene
b) HFE gene
c) SLE gene
d) MYH gene
b) HFE gene
Hereditary hemochromatosis (type 1 HH) is caused by a single mutation in the HFE gene (C282Y)
Which of the following is not true of HFE gene mutations?
a) HFE mutations exhibit penetrance
b) HFE mutations exhibit variable expressivity
c) only one copy of the mutated allele is required for expression
d) HFE mutations exhibit a sex-influenced phenot
c) only one copy of the mutated allele is required for expression
Mutations exhibit penetrance, variable expressivity and sex-influenced phenotype
A patient presents with cardiomyopathy, arthritis, and hyperpigmented skin. Imaging shows an enlarged liver with signs for possible cirrhosis or hepatocellular carcinoma. Physical exam reveals shrunken testicles. This patient is most likely exhibiting sig
c) late stage hemochromatosis
LATER SIGNS & SYMPTOMS include hepatomegaly, hepatic cirrhosis, hepatocellular carcinoma, diabetes mellitus, cardiomyopathy, hypogonadism, arthritis, and hyperpigmented skin.
A patient presents with right upper quadrant pain, fatigue, and arthralgias. They are most likely exhibiting signs and symptoms of:
a) sickle cell anemia
b) early stage hemochromatosis
c) late stage hemochromatosis
d) none of the above
b) early stage hemochromatosis
EARLY SIGNS & SYMPTOMS include right upper quadrant, fatigue, and arthralgias.
You order a CBC and serum levels for a patient you suspect may have hemochromatosis. Which of the following lab results would indicate hemochromatosis? (select all that apply)
a) saturation of the molecule responsible for iron transfer
b) serum saturation
a) saturation of the molecule responsible for iron transfer
b) serum saturation of the molecule responsible for iron storage
d) elevated serum liver enzyme levels
Elevated transferrin saturation, serum ferritin concentrations and serum liver enzymes:
- tr
A ________________ biopsy with a hepatic iron index greater than 2 is diagnostic for hemochromatosis.
a) spleen
b) liver
c) kidney
d) bone marrow
b) liver
Genetic testing for mutations of the HFE gene are performed through:
a) gel electrophoresis
b) polymerase chain reaction analysis
c) gram staining
d) serum iron levels
b) polymerase chain reaction analysis
PCR for HFE gene