challenge: What is the association between mutations in the DCDC2 gene and a specific learning disorder?
  
  A. Mutations in DCDC2 have no known impact on learning disorders
  B. Mutations in DCDC2 are linked to an increased risk of mathematics disability
  C. Mutations in DCDC2 are associated with reading disability, also referred to as developmental dyslexia
  D. Mutations in DCDC2 are correlated with an increased risk of attention deficit hyperactivity disorder
  Answer: 