In hereditary spherocytosis mutation not seen is?

Hereditary spherocytosis is an inherited disorder caused by intrinsic defects in RBC membrane skeleton that render red cells spheroid less deformable and vulnerable to splenic sequestration and destruction. The pathogenic mutation most commonly affect ankyrin, band 3, spectrin or band 4.2. No Na cl channel protein mutation is seen. Ref:Robbins and Cotran Pathologic basis of disease.South Asia Edition-9 volume 1.page no. 632,633