Yu, Lung-ChihLung-ChihYuLin, MarieMarieLin2012-10-202018-07-062012-10-202018-07-062011http://ntur.lib.ntu.edu.tw//handle/246246/243345Purpose of review: The molecular genetics of the blood group I system and the regulation mechanism for I antigen expression in postnatal red blood cells are intriguing. This review summarizes their elucidation and recent findings. RECENT FINDINGS: Accumulating data from the molecular analysis of individuals with the adult i phenotype supports the proposed molecular genetic mechanism for the partial association of the adult i phenotype with congenital cataracts. Recent investigations have shown that the regulation of I antigen formation during erythropoiesis is determined by transcription factor CCAAT/enhancer binding protein-α (C/EBPα) and the phosphorylation status of C/EBPα Ser-21 residue. Summary: The human I locus is organized such that it has an uncommon genetic architecture and expresses three different I transcript forms. The results obtained from molecular analysis of two adult i groups, with and without congenital cataracts, demonstrate that the molecular background accounts for the partial association between these two traits and suggest that an I gene defect may lead directly to the development of congenital cataracts. Analysis of the regulation for I antigen expression shows that the regulation during erythropoiesis and granulopoiesis share a common mechanism, with dephosphorylation of the Ser-21 residue on C/EBPα playing the critical role. ? 2011 Wolters Kluwer Health | Lippincott Williams & Wilkins.en-USadult i phenotype; blood groups; CCAAT/enhancer binding protein-α; congenital cataracts; I antigen[SDGs]SDG3blood group I antigen; CCAAT enhancer binding protein alpha; serine; antigen expression; congenital cataract; dephosphorylation; erythropoiesis; gene locus; granulopoiesis; human; molecular genetics; perinatal period; phenotype; priority journal; protein phosphorylation; regulatory mechanism; review; Cataract; Erythrocytes; Erythropoiesis; Glycosphingolipids; Humans; I Blood-Group System; Leukopoiesisjournal article10.1097/MOH.0b013e32834baae92-s2.0-80054744145http://ntur.lib.ntu.edu.tw/bitstream/246246/243345/-1/44.pdf