How do people inherit Emery-Dreifuss muscular dystrophy?
Emery-Dreifuss muscular dystrophy can have several different patterns of inheritance. When this condition is caused by mutations in the EMD gene, it is inherited in an X-linked recessive pattern. A condition is considered X-linked if the mutated gene that causes the disorder is located on the X chromosome, one of the two sex chromosomes. In males (who have only one X chromosome), one altered copy of the gene in each cell is sufficient to cause the condition. Males are affected by X-linked recessive disorders much more frequently than females. A striking characteristic of X-linked inheritance is that fathers cannot pass X-linked traits to their sons. In females (who have two X chromosomes), a mutation typically must be present in both copies of the EMD gene to cause X-linked Emery-Dreifuss muscular dystrophy. Females who carry one altered copy of the EMD gene usually do not experience the muscle weakness and wasting that are characteristic of this condition. In some cases, however, they
