Gray code. The reflected binary code (RBC), also known as Gray code after Frank Gray, is a binary numeral system where two successive values differ in only one bit (binary digit). The reflected binary code was originally designed to prevent spurious output from electromechanical switches.
Neural tube defects happen when the neural tube does not close as expected. Anencephaly occurs when the end of the neural tube that would have developed into the brain does not close properly, resulting in the failure of the development of major portions of brain, skull and scalp.
And unfortunately, her premonition was correct. At 12 weeks, the couple learned that one of the identical twin daughters, the baby girl they had named Skye, would not live past birth due to a condition called anencephaly. With anencephaly, part of the brain does not develop normally.