reet
Forum Fanatic
Topics: 152
Posts: 1,411
|
A female neonate has profound hypotonia. The only known complication of pregnancy was polyhydramnios. The mother has a lack of facial expression and weak muscles; she says she did not have any problems as an infant or child. Which of the following best explains the difference in presentations in the mother and child?
A) Anticipation
B) Delayed onset
C) Genetic heterogeneity
D) Incomplete penetrance
E) Pleiotropy
___________________
Live as u were to die tommorow. Learn as if u were to live forever.
|
| reet
Forum Fanatic
Topics: 152
Posts: 1,411
|
SEE ATTACHMENT..
38. A 3-year-old boy is suspected of having an X-linked immunodeficiency. To establish the pattern of transmission of this genetic defect, DNA is extracted from the T and B lymphocytes of his parents, his two sisters ages 5 and 7 years, and his 3-month-old brother. After restriction enzyme digestion, the digested DNA is subjected to gel electrophoresis and probed with a DNA marker that distinguishes the maternal and paternal X chromosome alleles. The results are shown. Based on this DNA analysis, which of the following statements is correct concerning the inheritance of this genetic deficiency?
A) The brother has inherited the defective gene
B) Both parents can transmit the defective gene
C) Sister 1 is a carrier
D) Sister 2 is a carrier
E) Both sisters are carriers
F) Neither sister is a carrier
Attached Files:
Doc3.doc (28 KB, 108 downloads)
Edited by reet on 02/09/06 - 09:56 AM
___________________
Live as u were to die tommorow. Learn as if u were to live forever.
|
| druas
Forum Elite
Topics: 47
Posts: 339
|
1) anticipation
2) ??
|
| Natasa
Forum Elite
Topics: 9
Posts: 291
|
Myotonic dystrophia for the first and I agree with druas-ANTICIPATION.(due to increased number in CTG repeats).
AS for the second:Where are the results shown?
|
| Natasa
Forum Elite
Topics: 9
Posts: 291
|
I thought it would be E but on the second thought:If mother is heterozygous(carrier) and father is affected-there is 50-50 chances for the sisters to be carriers and 50% of sons will be affected with the disorder.
So-both mother and father can transmit the gene?
|
| reet
Forum Fanatic
Topics: 152
Posts: 1,411
|
attachment below...
In the family represented by the pedigree, affected persons have a disease characterized by mitochondrially inherited late-onset optic atrophy. Assuming that the family and personal medical history of the partner is unremarkable, the risk for optic atrophy to develop in the male child of IV-9 is closest to<?
A ) 0%
B ) 25%
C ) 50%
D ) 75%
E ) 100%
Attached Files:
photo.doc (37 KB, 83 downloads)
Edited by reet on 02/09/06 - 09:57 AM
___________________
Live as u were to die tommorow. Learn as if u were to live forever.
|
| abissun
Forum Senior
Topics: 2
Posts: 16
|
1) A. Anticipation
2) D. Sister 2 is carrier
3) A. 0%
whts the ans reet?
|
| doc179
Forum Guru
Topics: 67
Posts: 1,217
|
I agree with abissum for the ans for all the 3 qs
|
| elisamik
Forum Senior
Topics: 2
Posts: 39
|
agree w/abissum as well.
|
| msyamp
Forum Fanatic
Topics: 60
Posts: 1,462
|
answer is what abissm said.
___________________
If you think you can You can! If you think you cant you are right again!!
|
| Geroo
Forum Guru
Topics: 114
Posts: 799
|
can someone axplain q 3 please.why 0%?
|
| msyamp
Forum Fanatic
Topics: 60
Posts: 1,462
|
it is leber's optic atrophy also called mitochondrial optic atophy. it is a mitochondrially transmitted. it is transmitted from the ovum(mother) but not sperm(father) to the children.so here IV 9 is a male and father. he produces only sperms so cannot transmit mitochondria to his any child. so no disease.
___________________
If you think you can You can! If you think you cant you are right again!!
|
| ts97
Forum Senior
Topics: 13
Posts: 128
|
For question 3: isn't it 100% (E) the answer? The child VI-9 has the mother affected, so he is affected too, as his siblings VI-8 and VI-10.
|
| elissa
Forum Newbie
Topics: 2
Posts: 49
|
ts97 : the question relates to the offspring of IV9. IV9 is male. his sperm has mito in the tail, which drops off at conception, so no male mito can be passed on to the next generation....only female. There's also another thread about this. 
|
|
| |
| | | | | | | | | | | | | | |
