Krabbe is a genetic disease only transferred by both mother and father. It is not determined by gender. Any children conceived by carrier parents have a 1 in 4 chance of being affected; a 1 in 4 chance of being a non-carrier; and a 2 in 4 chance of being a carrier. Being a carrier does not affect the child's functioning and can only be detected through genetic testing of the DNA code.
The disease itself is an error in the genes that does not allow for proper nerve development in the brain. Each nerve in the body is surrounded by a myelin sheath which carries the electrical impulses to every other nerve. In Krabbe, this sheath is not forming correctly, thereby not allowing a full and proper message to be carried to other nerves.
The area most affected by this is the central nervous system. The CNS controls such things as breathing, body temperature, and all other automatic body functions. Because these functions affect so many others, seizures occur, digestion is inhibited. The body, without many of these basic things, is subjected to a domino effect of other problems--poor muscle control being the one thing that inhibits these children from learning the basic milestones.
The disease eventually affects all brain areas--the nerves not being used, begin to die and with nerve death, areas within the brain begin to shut down and die. This is a terminal illness. Without proper brain functioning the body begins to shut down.