The function of G-Protein’s become defective and abnormal after the addition ADP-ribose to the G protein by the A sub unit. this phenomenon is called as ADP-ribosylation which result in the permanent activation of G-protein . When the G-Protein become active, the enzyme adenyl cyclase converts ATP into cAMP. Increase concentration in the cAMP blocks the transportation of sodium from the lumen into the bloodstream. the amount of Chloride and bicarbonate also increases. Due to the continuous increase of the ions, water moves into by osmosis from the bloodstream and cholera occurs.
Then, we can say the genotype of both the parents was heteroxenous... It is because, o is recessive and can dominant only in presence of other recessive gene.
So, both parents blood group genotype would be: Ib Io
