The human major histocompatibility com-plex includes approximately 14 class II HLA genes within the HLA-D region, most of which exist in multiple allelic forms.One of these genes, the DQ3.2.3 gene, accounts for the well-documented association of HLA-DR4 with insulindependent diabetes mellitus and is the single allele most highly correlated with this disease. We analyzed the

No abstract

The molecular basis for the hereditary persistence of fetal hemoglobin (HPFH) phenotype was studied in a Chinese individual who was heterozygous for a nondeletion form of A gamma-HPFH. Both allelic A gamma-globin genes were isolated by molecular cloning and subjected to nucleotide sequence analysis. One A gamma gene promoter showed a cytosine to thymine transition at position -196, whereas the other promoter was normal. This mutation at position -196 has now ben found in unrelated individuals with the A gamma-HPFH phenotype from Italy, Sardinia, and China, suggesting that it may have arisen independently. The implications of this mutation for models of fetal globin gene switching are discussed.