The great white shark is very well known for its size, with the  largest individuals known to have approached or exceeded 6 metres  (20 ft) in length and 2,268 kilograms (5,000 lb) in weight. It  reaches maturity at around 15 years of age and can have a life span  of over 30 years.
Benign fasciculation syndrome is characterized by occasional or nearly continuous twitching of various skeletal (voluntary) muscles in the body. This type of muscle twitching can also be seen in association with serious disorders like spinal injury, multiple sclerosis (MS) or amyotrophic lateral sclerosis (ALS).
Because records on ALS have not been kept throughout the country, it is hard to estimate the number of ALS cases in the United States. ALS is slightly more common in men than women. ALS is age related; most people find out they have it when they are between 55 and 75 years of age, and live from 2 to 5 years after symptoms develop. How long a person lives with ALS seems to be related to age; people who are younger when the illness starts live slightly longer. To read the latest prevalence of ALS for Oct. 2010 â December 11, 2011, click here. About 5â10% of ALS cases occur within families.