Question

1) What is the germline genotype? How is the germline genotype typically determined (what tissue(s))?

2) Why are the vast majority of somatic mutations not detectable in a blood test?

3) 72 year old woman diagnosed with breast cancer (no family history). IF there is a

BRCA1 mutation involved, what samples do you need to collect to genotype?

a. blood

b. tumor

c. urine

d. normal mammary tissue from the other breast

for 3 I got B since sporatic cancer cannot be tested wit blood, so you have to test the tumor itself or am I wrong?

Answer 1

1. Germline genotype

              * Germline genotype is a collection body cells or tissues which are well diffferenciated or

                 segregated in the processes of reproduction and they can pass on their genetic materials

                 to next generation.

                  Eg; gamates such as egg and sperm.

2. Somatic mutations are quit small and it is very inconsistent between cells that result in low threshold

    to trigger variant calling when checking the blood sample so it is difficult to detect in blood test.

3. b) Tumor, Tumor cells are used as a sample for this type of sporatic or non-hereditory cancers and

        now use Microarray analysis (DNA microarry) is one of the method for detection of this type of

         tumors.