Dyggve-Melchior-Clausen syndrome is a very rare genetic disorder that is characterized by a childhood-onset of mental retardation, microcephaly, various facial changes, and a range of skeletal abnormalities that affect the trunk, the spine, and the limbs. An autosomal recessive pattern of inheritance is established and the majority of patients have affected siblings or first-degree relatives. The diagnosis can be made through a physical examination, a patient history, and plain X-rays of the skeleton.
The clinical presentation of Dyggve-Melchior-Clausen syndrome (DMC), initially described approximately 50 years ago , is distinguished by a combination of several features that develop in early childhood      :
Because Dyggve-Melchior-Clausen syndrome is very rare, the diagnosis may be difficult to attain without a thorough diagnostic workup. Since affected children develop the typical clinical presentation in the first several years of life, the physician should first obtain a detailed patient history from the parents. The history should cover the onset of symptoms and their progression, as well as severity. The fact that many identified patients either come from consanguineous marriages or have first-degree relatives who already suffer from Dyggve-Melchior-Clausen syndrome makes a complete family history crucial for identifying a genetic background of the disease. As soon as clinical suspicion is raised, imaging studies should be employed. Plain radiography of the axial skeleton, the pelvis, and the limbs is the key step for determining the exact type of deformity  . One of the most specific findings seen in this syndrome is the lace-like character of the iliac crests. Small iliac wings, bilateral hip dislocation, a widened pubic symphysis, acetabular hypoplasia, a wide sacroiliac joint and deformed femoral heads are other prominent findings in the hips in these patients  . A barrel-shaped chest with broad ribs, platyspondyly, and a double-hump shape of the bone end-plates provide sufficient evidence to make a solid diagnosis of Dyggve-Melchior-Clausen syndrome  . Genetic studies can be used as a definitive method, which confirm mutations of the dymeclin gene located on chromosome 18     .