Question: How many people are affected by Emery-Dreifuss muscular dystrophy ?
Answer: X-linked Emery-Dreifuss muscular dystrophy is the most common form of this condition, affecting an estimated 1 in 100,000 people. The autosomal recessive type of this disorder appears to be very rare; only a few cases have been reported worldwide. The incidence of the autosomal dominant form is unknown.
Source: GHR

Question: Is Emery-Dreifuss muscular dystrophy inherited ?
Answer: 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 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 may experience heart problems associated with this disorder. Other cases of Emery-Dreifuss muscular dystrophy result from mutations in the LMNA gene and are considered to have an autosomal dominant pattern of inheritance. Autosomal dominant inheritance means one copy of the altered gene in each cell is sufficient to cause the disorder. About 75 percent of autosomal dominant Emery-Dreifuss muscular dystrophy cases are caused by new mutations in the LMNA gene and occur in people with no history of the disorder in their family. In the remaining cases, people with this form of the condition inherit the altered LMNA gene from an affected parent. Rarely, LMNA gene mutations can cause a form of Emery-Dreifuss muscular dystrophy that is inherited in an autosomal recessive pattern. Autosomal recessive inheritance means two copies of the gene in each cell are altered. Most often, the parents of an individual with an autosomal recessive disorder are carriers of one copy of the altered gene but do not show signs and symptoms of the disorder.
Source: GHR