The great white shark is notable for its size, with mature female individuals growing up to 6.1 m (20 ft) in length and 1,950 kg (4,300 lb) in weight. However most are smaller, males measuring 3.35 to 3.96 m (11 ft 0 in to 13 ft 0 in) and females 4.57 to 4.88 m (15 ft 0 in to 16 ft 0 in) on average.
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.
By analyzing brain tissue from patients with ALS or FTD, Dr. Petrucelli and his team discovered that the abnormal protein, which they call C9RANT, is generated as a result of repeat expansions of nucleotides in the noncoding region of the C9ORF72 gene. These expansions are the most common cause of ALS and FTD.