Given a question and a context passage, generate the answer having the word or phrase from the context passage. Here, the answer should be a shortest continous span from the passage.

Context: The authors describe a family with six patients with muscular dystrophy with a variable course. One is a compound heterozygote for CAPN3 mutations (calpainopathy) and the others have a single CAPN3 mutation. Linkage analysis and sequencing revealed a XK gene mutation (McLeod syndrome). This illustrates the variable phenotype of XK mutations and suggests the possibility that CAPN3 heterozygotes may have their condition caused by nonallelic mutations in other unrelated genes. 
 Question: Mutation of which gene is associated with McLeod syndrome?
xk

Context: Looking to stop a three-game losing streak, the Raiders welcomed Derek Carr back after missing one week due to injury to face the Los Angeles Chargers. However, things did not start well for Carr as he threw an interception on his first pass of the day and the Chargers took over at the Raider 30-yard line. the defense held the Chargers to a field goal attempt from 48 yards out which was no good. The Raiders took advantage and moved the ball down the field before Carr hit Michael Crabtree from 23 yards out to give the Raiders a 7-0 lead. Neither team could muster much offense until midway through the second quarter when the Chargers moved 82 yards and scored on a Melvin Gordon touchdown run from one yard out to tie the game. With, 1:34 remaining in the half, the Raiders moved into Charger territory and connected on a Giorgio Tavecchio 44-yard field goal as time expired to give the Raiders a 10-7 lead at the half. On their first possession of the second half, the Raiders moved deep into Charger territory, but managed no points as Carr was intercepted for the second time in the game. The teams exchanged punts and fumbles as the game moved into the fourth quarter. The Chargers finally managed some offense as Philip Rivers hit Melvin Gordon for a six-yard touchdown pass to give the Charger at 14-10 lead. On their ensuing possession, Cordarrelle Patterson took the ball on an end around and scampered 47 yards for a touchdown. Giorgio Tavecchio would, however, miss the ensuing point after to leave the Raider lead at two points, 16-14. After exchanging punts, the Chargers took over with 4:09 remaining in the game. Rivers hit Hunter Henry for a 23-yard pass play to move the ball into Raider territory. with less than two minutes remaining, the Chargers moved the ball to the Raider 10 yard line and lined up for the game-winning field goal with three second left in the game. The field goal was good and the Raiders suffered their fourth straight loss, falling to 2-4 on the season. The four losses through six gamed equaled the number of losses they suffered the entire season the prior year. The Raider defense again struggled, giving up 343 total yards while the offense struggled as well, managing only 274 yards. Carr's two interceptions proved costly in his return. After the game, the team said his poor play was not due to his injury. 
 Question: Who is the Raiders field goal kicker?
giorgio tavecchio

Context: Lysine 1423 of neurofibromin (neurofibromatosis type I gene product [NF1]) plays a crucial role in the function of NF1. Mutations of this lysine were detected in samples from a neurofibromatosis patient as well as from cancer patients. To further understand the significance of this residue, we have mutated it to all possible amino acids. Functional assays using yeast ira complementation have revealed that lysine is the only amino acid that produced functional NF1. Quantitative analyses of different mutant proteins have suggested that their GTPase-activating protein (GAP) activity is drastically reduced as a result of a decrease in their Ras affinity. Such a requirement for a specific residue is not observed in the case of other conserved residues within the GAP-related domain. We also report that another residue, phenylalanine 1434, plays an important role in NF1 function. This was first indicated by the finding that defective NF1s due to an alteration of lysine 1423 to other amino acids can be rescued by a second site intragenic mutation at residue 1434. The mutation partially restored GAP activity in the lysine mutant. When the mutation phenylalanine 1434 to serine was introduced into a wild-type NF1 protein, the resulting protein acquired the ability to suppress activated phenotypes of RAS2Val-19 cells. This suppression, however, does not involve Ras interaction, since the phenylalanine mutant does not stimulate the intrinsic GTPase activity of RAS2Val-19 protein and does not have an increased affinity for Ras proteins. 
 Question: Which is the gene mutated in type 1 neurofibromatosis?

nf1