A boy and his maternal uncle have haemophilia A. Polymerase chain reaction (PCR) analyses of three exons of the gene responsible for haemophilia A, F8C, are shown in the figure below. The analyses included DNA from a normal male (lane 1), the affected boy (lane 2), his affected uncle (lane 3), and the boy’s mother (lane 4).
What is the most likely explanation for the presence of a band corresponding to exon 4 in the mother?
The mother:
Wähle eine der folgenden: