Genetic Diagnosis

Question 1

What is an indirect diagnosis?

Answer 1

Markers are used to infer whether the individual has inherited the chromosome segment containing the disease-causing mutation

Question 2

When do you use southern blot rather than PCR in a RFLP analysis?

Answer 2

• When the studied gene has a too long polymorphism to amplify with a PCR. Ex: myotonic dystrophy
• in indirect genetic analysis

Question 3

When do you use an indirect genetic analysis using STRP?

Answer 3

STRP allow establish markers of the locus causing disease - can have multiple alleles (each one with different numbers of repeats) ▶️ make then linkage analysis

Question 4

RFLP can be used for direct and indirect test, but what is the different?

Answer 4

• direct test: mutation causing disease is the same as the one that alters the restriction site
• indirect test: the mutation of the restriction site (marker) has occurred independently of the mutation site. Is better if is near with the mutation causing disease - must establish linkage phase

Question 5

What is the major limitation of the direct genetic analysis?

Answer 5

Must know the disease causing mutation.

Question 6

What is a direct genetic diagnosis?

Answer 6

The mutation itself is examined