Final answer:
Duchenne muscular dystrophy (DMD) has an X-linked recessive inheritance pattern, affecting primarily males with females typically being carriers. Symptoms start in early childhood with muscle weakness, eventually leading to severe mobility loss and breathing difficulties.
Step-by-step explanation:
Duchenne Muscular Dystrophy Inheritance
Duchenne muscular dystrophy (DMD) is a severe form of muscular dystrophy primarily affecting boys due to its X-linked recessive inheritance pattern. Males have one X and one Y chromosome, while females have two X chromosomes. In the case of DMD, a mutation on the X chromosome causes the disease. Since males only have one X chromosome, if it carries the mutation, they will express the disorder. Females, however, have two X chromosomes and must have the mutated gene on both to express the disease, which is extremely rare. Hence, females are typically carriers of the disorder without showing symptoms.
The progression of DMD includes a decline in muscle function, starting with the lower limbs and eventually affecting the upper body. Initial symptoms are often seen when a child begins walking, with difficulties in motion and balance. As the disease advances, muscle strength decreases, leading to a dependence on mobility aids and, ultimately, respiratory failure. This pattern of progression and the vital functions it impacts are crucial when discussing DMD's consequences.