Tamoxifen has to be metabolized via first pass metabolism to an active metabolite (endoxifen). The patient has decreased concentrations of the metabolized product indicating that the patient’s pair of cytochrome P450 alleles aren’t metabolizing tamoxifen correctly. The question is asking what the chances are the sister has the same genotype, which would be 25% --> 1/2 * 1/2 = 1/4
If some one can help me understand bc im a bit confused. I understand the thought process and I realized that this was an AR disease and I also got the 1/4 affected, 1/2 carrier and 1/4 unaffected. But I chose 0% bc I figured if it was an AR disease the 1 child already diseased was homozygous affected (1/4 affected). Which lead me to think that the other sister was either a carrier or not affected at all. Am I just over thinking this or am I not fully understanding whats going on?
submitted by bubbles(31), 2019-06-08T22:34:28Z
Can someone explain properly how we know that this trait follows Mendelian genetics and is autosomal recessive and furthermore how the parents were heterozygous?
I guessed a lot on this question and got lucky :(