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).
For most ALS genes, only one mutated copy is needed to cause disease. This is called a âdominantâ gene. For other genes, both copies must be mutated to cause disease. This is called a ârecessiveâ gene. During formation of eggs and sperm, gene pairs split up, so that an egg (or sperm) contains only one gene copy.