What are the signs and symptoms of Dyggve-Melchior-Clausen syndrome? Affected newborns may be small at birth, but otherwise appear normal. Skeletal findings are often recognized first between 1 and 18 months. With age, other characteristics begin to develop. Chest deformities, feeding difficulties, and developmental delay usually occur before 18 months. Disproportionate short stature usually occurs after 18 months. Additional features may include a long skull, distinctive facial appearance, a protruding jaw, microcephaly, and claw-like hands. Intellectual disability occurs in most cases, ranging from moderate to severe. Affected individuals can also develop a protruding breastbone; spinal abnormalities; abnormal bones in the hands, fingers, toes, wrists, and long bones of the arms and legs; and joint contractures, especially of the elbows and hips. Secondary problems resulting from the skeletal abnormalities may include spinal compression, dislocated hips, and restricted joint mobility. These problems may in turn cause a waddling gait. The Human Phenotype Ontology provides the following list of signs and symptoms for Dyggve-Melchior-Clausen syndrome. If the information is available, the table below includes how often the symptom is seen in people with this condition. You can use the MedlinePlus Medical Dictionary to look up the definitions for these medical terms. Signs and Symptoms Approximate number of patients (when available) Abnormality of epiphysis morphology 90% Abnormality of the hip bone 90% Abnormality of the metaphyses 90% Cognitive impairment 90% Limb undergrowth 90% Pectus carinatum 90% Short stature 90% Short thorax 90% Skeletal dysplasia 90% Abnormality of the metacarpal bones 50% Abnormality of the wrist 50% Hyperlordosis 50% Hypoplasia of the odontoid process 50% Kyphosis 50% Limitation of joint mobility 50% Microcephaly 50% Neurological speech impairment 50% Sloping forehead 50% Spinal canal stenosis 50% Attention deficit hyperactivity disorder 7.5% Autism 7.5% Shoulder dislocation 7.5% Abnormality of the nervous system - Autosomal recessive inheritance - Avascular necrosis of the capital femoral epiphysis - Barrel-shaped chest - Beaking of vertebral bodies - Brachycephaly - Broad foot - Broad palm - Camptodactyly - Carpal bone hypoplasia - Coarse facial features - Cone-shaped epiphyses of the phalanges of the hand - Coxa vara - Deformed sella turcica - Disproportionate short-trunk short stature - Distal ulnar hypoplasia - Enlargement of the costochondral junction - Flat acetabular roof - Flat glenoid fossa - Genu valgum - Hallux valgus - Hypoplastic facial bones - Hypoplastic iliac wing - Hypoplastic ischia - Hypoplastic pelvis - Hypoplastic sacrum - Hypoplastic scapulae - Iliac crest serration - Irregular iliac crest - Lumbar hyperlordosis - Mandibular prognathia - Multicentric ossification of proximal femoral epiphyses - Multicentric ossification of proximal humeral epiphyses - Narrow greater sacrosciatic notches - Platyspondyly - Postnatal growth retardation - Prominent sternum - Rhizomelia - Scoliosis - Severe global developmental delay - Shield chest - Short femoral neck - Short metacarpal - Short metatarsal - Short neck - Spondyloepimetaphyseal dysplasia - Thickened calvaria - Thoracic kyphosis - Waddling gait - Wide pubic symphysis - X-linked recessive inheritance - The Human Phenotype Ontology (HPO) has collected information on how often a sign or symptom occurs in a condition. Much of this information comes from Orphanet, a European rare disease database. The frequency of a sign or symptom is usually listed as a rough estimate of the percentage of patients who have that feature. The frequency may also be listed as a fraction. The first number of the fraction is how many people had the symptom, and the second number is the total number of people who were examined in one study. For example, a frequency of 25/25 means that in a study of 25 people all patients were found to have that symptom. Because these frequencies are based on a specific study, the fractions may be different if another group of patients are examined. Sometimes, no information on frequency is available. In these cases, the sign or symptom may be rare or common.