Read the passage and answer the following question.
The genes that code for the human leukocyte antigen(HLA) antigens, also known as the major histocompatibility complex(MHC) genes, are all located on human chromosome $6$. Two brothers and a sister participated in a bone marrow donor registration, and their HLA typing results are given.
| ID |
HLA-A |
HLA-B |
HLA-C |
HLA-DR |
| $1$ |
A$1$, A$3$ |
B$5$, B$7$ |
C$3$, Cw$19$ |
DR$3$, DR$9$ |
| $2$ |
A$1$, A$6$ |
B$2$, B$6$ |
C$2$, C$16$ |
DR$4$, DR$13$ |
| $3$ |
A$1$, A$6$ |
B$2$, B$6$ |
C$2$, C$16$ |
DR$4$, DR$13$ |
The probability of the fourth sibling that would be similar to one of the three.