Interesting medical tidbits with an African twist

Back at PCH I worked with kiddos that had cancer - varying kinds including cancers of the blood or tumors of the central nervous system just to name a few. Here in Africa, there seems to be an unusually high amount of Burkitt's Lymphoma, which is a malignant cancer of the lymphatic system. I read somewhere that Burkitt’s accounts for almost 75% of African childhood malignancies but back in the US I saw just a handful of kids with Burkitt’s. I was talking about this with one of the physicians here and she shared this interesting fact with me:

Yep, Burkitt’s is the most common childhood cancer in equatorial Africa. Here in Africa they call it "endemic" Burkitt's which has a different etiology as compared to the "sporadic" Burkitt's at home in the states. With endemic Burkitt's there seems to be a connection between other common viruses that play a role in increasing risk for Burkitt’s. Epstein-Barr virus, which commonly causes mono, is one of these. B-lymphocytes in these children have been infected with EBV. Unfortunately EBV coupled with chronic malaria (which so many Africans have) causes a reduced resistance to the virus. This allows the virus to change the infected B-lymphocytes into cancerous cells, leading to the development of lymphoma. Interestingly though, in areas where malaria had been eradicated, Burkitt’s Lymphoma has declined dramatically. Who knew Malaria prevention might help eliminate cancer in Africa?

Back at PCH I also was part of a comprehensive clinic for kids with Sickle Cell Disease. Interesting fact #2: Those with Sickle Cell trait have a genetic advantage for malaria prevention.

Sickle Cell Disease is a blood disorder in which red blood cells are sickle shaped due to a hemoglobin gene mutation. The sickled cells get stuck in small blood vessels during periods of high activity, resulting in pain, fever, swelling and tissue damage – often called a vaso-occlusive crisis. In order to have full Sickle Cell Anemia you must have two copies of the mutant gene, one given by each parent. So those with just one mutant gene and one healthy gene have something called sickle cell trait. Kids with sickle cell trait don’t experience nearly the physical effect of the disease as those with sickle cell anemia.

The beauty of sickle cell trait is that it provides a reduced susceptibility to certain types of malaria. Since the gene is recessive, carriers can produce a few sickled red blood cells (too few to cause symptoms but just enough to provide resistance against malaria). The malaria plasmodium can’t infest itself fully in red blood cells that are sickled, so the cells rupture making the plasmodium unable to reproduce itself. In some African regions, up to 40 percent of the population carries at least one mutant hemoglobin gene, keeping Malaria away in these folks. It’s kind of crazy how genetics works out sometimes!