Chapter 5 practice questions

Question 1

Tay Sachs

Tranmission pattern:
Mutation::

Answer 1

AR

Frameshift mutation: 4 base-pair deletion for the gene that codes for the enzyme Hexaminidase A that leads to the appearance of a stop codon that stops reading early to make the enzyme nonfunctional (nonsense mutation)

Question 2

______ change the remaining sequences of AA in a protein

Answer 2

Frameshift mutation

Question 3

CF is what type of mutation

Answer 3

Non-frameshift mutation: 3 base pair deletion that removes AA 508 (Phe)

Question 4

Gaucher disease has a mutation of what enzyme

Answer 4

glucocerebrosidase

Question 5

Child is more prone to infections, has hepatosplenomegaly, anemia, leukopenia

what is this?

Answer 5

Gaucher disease (defeciency in glucocerebrocidase).

T1: No CNS involvement: splenomegaly and panocytosis, thrombocytopenia and bone problems; jews

T2: acute infantile with CNS involvement ; no jews

T3: intermediate (begins in adolscence or early adulthood

Question 6

Enzyme in Pompe disease

Answer 6

acid maltase (alpha 1,4 glucosidase)

Question 7

What are we likely to find in histo of Pompe disease

Answer 7

lysosomal storage of glyogen in all organs

CARDIOMEGALY IS MOST PROMINENT: GLYCOGEN IN MYOCARDIAL CELLS

Question 8

______ is a def in hexoaminidase A and is associated with severe mental retardation and death before 10 yo

Answer 8

Tay sachs

Question 9

In Robertsonian translocation, how much normal genetic material is present or deleted

Answer 9

ALMOST all is present because only a small amount of the p arm from each translocated chromosome is lost

Question 10

In balanced recipricol translocations, what is the possibility of inheriting the defect?

Answer 10

same possbility of inheriting defect exists.

Question 11

How do pts with Down syndrome who are mosciac vs those are have a complete extra chromosome present differently

Answer 11

In mosaic ppl, greater numbers of normal cells have the correct chromosomal compliments, which may allow the infant with severe abnormalaties of chromosome numbers to survive to term and beyond

Question 12

DiGeorge syndrome

Answer 12

Di-george syndrome is an immundeficieny d/t deletion of 22q11.2; decrease in TBX1 => pharyngeal arches 3, 4 and (5?)
Hypoparathyroidism => hypoplasia of thymus and parathyroid=> decrease in amount of T -cells (more prone to viral and fungal infections) and hypocalcemia

Question 13

bb has numerous biral and fungal infections since birth; hypocalcemia; chromosome 22

Answer 13

DIGEORGE SYNDROME => immunodefieincy d/t deletion of Chr22q11.2

Question 14

Fragile X syndrome is a loss of function disorder. describe what this means for this disease

Answer 14

Fragile X syndrome:

FMR1 protein is a translation regulator that help to reduce protein synthesis.

Thus, a reduction of FMR1P (loss of function) means that we will have increased protein translations from mRNA to alter their synpatic activity and cause mental retardation.