Please explain in detail the below: The data below comes from a young couple who
ID: 67412 • Letter: P
Question
Please explain in detail the below: The data below comes from a young couple who both have siblings with a genetic disorder of amino acid metabolism. The amino acid pathway that is disordered has 4 enzymes coded for by 4 independently assorting genes. You have the RFLP data collected from the couple (C1 and C2) their parents and their affected sibs (C1’s parents are P1 and P2 and the affected sib is S1) (C2’s parents are P3 and P4 and her affect sib is S2). Their parents are unaffected by the disorder. Each gene has an RFLP that is linked to the gene.
1) Based on this data is there a significant chance a child born to C1 and C2 will have the disorder? Explain why.
2) Are C1 or C2 carriers for the disorder? Explain why.
3) What is the probability a child born to C1 and C2 could be a double?
RFLP FOR GENE 1
size
P1
P2
S1
C1
C2
S2
P3
P4
14kb
X
X
X
X
X
10kb
X
X
X
X
8kb
X
X
X
4kb
X
X
X
RFLP FOR GENE 2
size
P1
P2
S1
C1
C2
S2
P3
P4
16kb
X
X
X
X
X
10kb
X
X
X
X
6kb
X
X
X
2kb
X
X
X
RFLP FOR GENE 3
size
P1
P2
S1
C1
C2
S2
P3
P4
20kb
X
X
X
X
X
15kb
X
X
10kb
X
X
X
X
X
X
45Kb
X
X
RFLP FOR GENE 4
size
P1
P2
S1
C1
C2
S2
P3
P4
12kb
X
X
X
X
10kb
X
X
X
X
X
X
X
8kb
X
X
6kb
X
size
P1
P2
S1
C1
C2
S2
P3
P4
14kb
X
X
X
X
X
10kb
X
X
X
X
8kb
X
X
X
4kb
X
X
X
Explanation / Answer
C1 and C2 both are carriers of the disease. Since both are carriers , there is definitely a chance of a child being born with the disease.
The 10kb locus present in gene 3 is actually responsible for disease in S1. This locus is also present in C1. The 2okb and 45kb locus of gene 3 is responsible for disease in S2. Out of these, 20kb locus is making C2 the carrier.
Talking directly, S1 and S2 siblings are affected, means all parents are carriers and the disease is autosomal recessive. So, probability of having a child with the disease in a cross between C1 and C2 will be 1/4.