<prompt> An afro-american kid of 6 years of age presented with abdominal pain, chronic hemolysis and abnormal RBC shape on peripheral smear. Most likely disorder responsible for this conditionTrinucleotide repeatPoint mutationAntibiodise against RBC membraneGenetic imprinting  <response>: Diagnosis here is sickle cell disease results from point mutation ,results in substitution of valine for glutamic acid at 6 position of beta globulin chain. Reference: GHAI Essential pediatrics, 8th edition 