Dyggve-Melchior-Clausen syndrome

DMC syndrome may be suspected following a thorough clinical evaluation, a detailed patient history, and identification of characteristic findings (e.g., barrel chest, and disproportionate short stature). Radiographs may confirm specific skeletal abnormalities and findings consistent with DMC syndrome. Genetic testing can also confirm a diagnosis.

GeneTests lists the name of the laboratory that performs clinical genetic testing for Dyggve-Melchior-Clausen syndrome. To view the contact information for this laboratory, click here.

Please note: Most of the laboratories listed through GeneTests do not accept direct contact from patients and their families; therefore, if you are interested in learning more, you will need to work with a health care provider or a genetics professional. Below, we provide a list of online resources that can assist you in locating a genetics professional near you.

Dyggve-Melchior-Clausen (DMC) syndrome is a rare, progressive genetic condition characterized by abnormal skeletal development, microcephaly, and intellectual disability. Only about 100 cases have been reported to date. Skeletal abnormalities may include a barrel-shaped chest with a short truck, partial dislocation of the hips, knock knees, bowlegs, and decreased joint mobility. A small number of affected individuals experience instability in the upper neck vertebrae that can lead to spinal cord compression, weakness and paralysis. Normally, there is growth deficiency resulting in short stature. DMC is caused by mutations in the DYM gene and is inherited in an autosomal recessive manner. Some researchers have described an X-linked pattern of inheritance, which has not been confirmed to date.

DMC syndrome is a progressive condition, meaning that signs and symptoms worsen over time. The orthopedic complications usually progress, which can include lumbar lordosis, thoracic kyphosis, scoliosis, dislocation in the hip joints, deformed knees, and spinal cord compression. Adult height is severely reduced with height ranging from 82 cm to 128 cm (32 in to 50 in). Neurological complications may include hyperactivity, autistic-like behavior, lack of speech, and mild to severe intellectual disability.

The overall health of an affected person is generally good and survival into adulthood is usual.

Treatment of individuals with DMC syndrome depends on the affected person's symptoms and is usually supportive. There is no cure for this condition. Treatments might include spinal fusion of the segments of the spinal column at the top of the spine or other means of vertebral stabilization. Additional surgical techniques may be used to correct various skeletal abnormalities such as dislocation of the shoulder and hip joints. In some cases, hip replacement is required. Children with DMC syndrome may benefit from early intervention and special educational programs.