Examples include hormones, enzymes, and antibodies. Each mature reproductive cell carries a single set of 23 chromosomes, half the amount as somatic cells. The tests indicate only a probability for developing the disorder. The several classes of RNA molecules play important roles in protein synthesis and other cell activities. The inheritance of these disorders follows the ratios first described by Gregor Mendel.
Normal females carry two X chromosomes.
Normal males carry one Y and one X chromosome.