This diversity is a result of its fast replication cycle, with the generation of about 1010 virions every day, coupled with a high mutation rate of approximately 3 x 10−5 per nucleotide base per cycle of replication and recombinogenic properties of reverse transcriptase.This complex scenario leads to the generation of many variants of HIV in a single infected patient in the course of one day. This variability is compounded when a single cell is simultaneously infected by two or more different strains of HIV. When simultaneous infection occurs, the genome of progeny virions may be composed of RNA strands from two different strains. This hybrid virion then infects a new cell where it undergoes replication. As this happens, the reverse transcriptase, by jumping back and forth between the two different RNA templates, will generate a newly synthesized retroviral DNA sequence that is a recombinant between the two parental genomes. This recombination is most obvious when it occurs between subtypes.The closely related simian immunodeficiency virus (SIV) has evolved into many strains, classified by the natural host species. SIV strains of the African green monkey (SIVagm) and sooty mangabey (SIVsmm) are thought to have a long evolutionary history with their hosts.
Neonatal Hemochromatosis is a rare and severe liver disease of unknown origin, though research suggests that it may be alloimmune condition. Its characteristics are similar to hereditary hemochromatosis, where iron deposition causes damage to the liver and other organs and tissues. Causes
The causes of neonatal hemochromatosis are still unknown, but recent research has led to the hypothesis that it is an alloimmune disease. Evidence supporting this hypothesis includes the high rate among siblings (>80%). This evidence along with other research indicates that neonatal hemochromatosis could be classified as a congenital alloimmune hepatitis. Diagnosis
Differential diagnosis
The condition is sometimes confused with juvenile hemochromatosis, which is a hereditary hemochromatosis caused by mutations of a gene called hemojuvelin. While the symptoms and outcomes for these two diseases are similar, the causes appear to be different. Treatment
Effective treatment of the disease has been confined to liver transplants. Success has also been reported with an antioxidant chelation cocktail, though its effectiveness cannot be confirmed. Based on the alloimmune cause hypothesis, a new treatment involving high-dose immunoglobulin to pregnant mothers who have had a previous pregnancy with a confirmed neonatal hemochromatosis outcome, has provided very encouraging results. References
Further reading
Andrews N (1999). "Disorders of iron metabolism". New England Journal of Medicine. 341 (26): 1986–95. doi:10.1056/NEJM199912233412607. PMID 10607817. link

External links
Hemachromatosis page at the National Center for Biotechnology Information