Malaria and Alexander the great: how important is family history?

Alexander the Great died from an acute febrile illness in 323 BC. Recent analyses have suggested several possible causes of his death and one among them is malaria. However, the analyses of Alexander's terminal illness have failed to consider his family history. Carriers of mutations for alpha and beta thalassemias, and glucose-6-phosphate dehydrogenase deficiency are protected against severe forms of malaria and their pattern of inheritance is well established. Alexander c father; Phillip II, was from Macedonia where selection pressure from malaria was strong. Accordingly, he likely possessed one or more of the protective genotypes. His mother Olympias, however, was a descendant of Doric migrants from the North and her ancestors resided subsequently for centuries in the mountainous Epirus where selection pressure of malaria was weak. Hence it is unlikely that she possessed one or more of the genotypes protective against malaria. Therefore, the relative risk of Alexander the Great being genetically more susceptible to and succumbing from malaria was greater than for his father and the Macedonian generals among whom he died

Cancer excess from consanguinity in Arab Emirates-Analysis of effect of consanguinity rate and relative risk

Consanguinity increases the chances of homozygosity, and homozygosity of cancer-susceptibility genes was shown to increase the risk of malignancy. Consanguinity is associated with increased cancer risk in younger individuals in studies from Asia, Europe, and North America. Among the citizens of United Arab Emirates [UAE], studies have found that consanguinity rate is around 50% and the relative risk [RR] of cancer in younger individuals with consanguineous parents is between 1.1 ans 2.1. The objective of the study was to estimate: i]the absolute number of cancer cases in UAE that could be attributed to parental consanguinity and ii] the changes that would occur in absolute number of cancer cases as a result of changes in consanguinity rates. These calculations were performed using a population less than 55-year-old, consanguinity rates, relative risk and incidence of cancer. The cancer incidence and population data were obtained from the Cancer Registry of UAE. To examine the changes that would occur in the excess number of cancer cases using different consanguinity rates within the range of RR we used consanguinity rates that varied from 0 to 60% and RR, from 1.1 to 2.1. The calculation shows that among 100.000 individuals younger than 55, between 1.5 and 10 individuals developed cancer attributable to parental consanguinity. The absolute number of cases in the country lies between 10 and 65. The cancer risk attributable to consanguinity is approximately between 9% and 52%. In conclusion, the absolute number of cancer cases in UAE attributable to parental consanguinity is relatively small