The A allele codes for a specific glycosyltransferase enzyme called α-1-3-N-acetylgalactosaminyltransferase. This enzyme's job is to take a sugar molecule called N-acetylgalactosamine and attach it to the end of the H antigen precursor structure on red blood cells. This addition converts the H antigen into the A antigen. The enzyme is very specific in the sugar it transfers and where it places it. The B allele codes for a different, but similar, enzyme (α-1-3-galactosyltransferase) that transfers a different sugar (galactose). The O allele produces a non-functional enzyme, so no sugar is added, and the H antigen remains unmodified.

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Zambia

• loveness Phiri – 1084 pts

• Visual Pathway Lesions
• Positive and Negative Symptoms
• Hallucinations and Delusions
• Antipsychotic Medications
• Emergency: Environmental Emergencies