Sickle Cell anaemia all are true except
The shift from HbF to HbS occurs due to point mutation.
Microvascular occlusion is a severe complication of SCA
Deoxygenation of RBC can lead to extensive membrane damage
Adults but not children; with  sickle  cell  disease  are  functionally  asplenic,  making them  susceptible  to  infections  caused  by  encapsulated  bacteria,  such  as  pneumococci.