causes condition has contributing genetic variation causes molecular phenotype Alpha Thalassemia Genotype Reduced Alpha/Beta Synthesis Ratio Alpha Thalassemia Silent Carrier Alpha Thalassemia Silent Genotype Request inclusion into relevant ontology -/alpha alpha/alpha SCDO (Jade Hotchkiss) None A genotype whereby one of the four alpha-globin genes is faulty, either as a result of a single nucleotide variant (SNP) or of a deletion. Heterozygous Deletion of HBA1 or HBA2