Which Genetic or Chromosomal Abnormality Below Is Correctly Described

Multiple Choice

Which genetic or chromosomal abnormality below is correctly described?

A) In phenylketonuria, a child is unable to produce a critical enzyme, which results in an accumulation of poisons and in turn causes profound intellectual disabilities.
B) In Tay-Sachs disease, the body starts producing abnormally shaped red blood cells.
C) In Down syndrome, the brain tissues of the cortex degenerate, resulting in death.
D) In sickle-cell anemia, a child receives an extra chromosome resulting in mental retardation.