They are at least a thousand times larger than the 1980 eruption of Mount St. Helens, which produced only 1 km3 (0.2 cu mi) of material, and at least six times larger than the 1815 eruption of Mount Tambora, the largest eruption in recent history, which produced 160 km3 (38 cu mi) of volcanic deposits.
Listen. 1  This severe homocystinuria is caused by rare MTHFR gene mutations (sometimes in combination with a second common MTHFR gene mutation). In severe MTHFR deficiency, signs and symptoms become apparent in infancy, however the condition can be milder, presenting in later childhood or adulthood.
The most common symptoms are similar to a flu-like or mononucleosis-like illness within several days to weeks after exposure to the virus, including. 1  fever; 2  headache; 3  open sores or ulcers in the mouth (like canker sores, also known as aphthous ulcers); 4  fatigue; weight loss;  sweating or night 1  sweats; appetite 2  loss; rash that may come and go quickly;