These changes were tested by a narrower band size and increasing migration of RBC plasma membrane proteins band 3 and band 4.5 using SDS-PAGE.15,16 The details of the mechanism of development of CDA II remain to be clarified in patients given the lack of an analogous animal model although it is an autosomal recessive disease associated with mutations in SEC23B responsible for coding a core component of the coat protein complex.6 This evidence concerns the gene SEC23B and autosomal recessive disease.