Support in coping with the effects of the disease is available through the MND Associations in each State, and research is being undertaken which gives hope for the future. Other fact sheets, including Genes and Chromosomes, Genetic Counselling, Prenatal Diagnosis, and Drawing up your Family Health Tree, are available from the Genetics Education Program of NSW , P O Box 317, St Leonards, NSW 2065. Choi WT, Zajac JD et al. When a baby is conceived, each parent passes on one copy of each of their genes to the baby. The sex of a child is determined by inheritance from their parents of X and Y chromosomes.
Females have two X chromosomes, one from each parent.
The sons of men with Kennedy's disease do not get the disease, and do not pass on the mutation. The daughters of men with Kennedy's disease are called obligatory carriers . Females have two X-chromosomes, one from their father, and one from their mother. Since males have only one X chromosome to pass on, their daughters always receive the X chromosome carrying the genetic mutation. Because they also have a normal X chromosome, they do not develop the disease.