2012, Number 40
Oral 2012; 13 (40)
Ochoa CFS, De Dios CA, Aparicio RJM, Cabrera SS, Hernández TN
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ABSTRACTPseudoachondroplasia is a genetic disease characterized by a growth factor alteration, is a disorder of bone growth; is characterized by severe growth deficiency and deformations such as bow legs and hyperlordosis. Prevalence is estimated at around 1/60,000. The disorder is usually discovered during the second year of life with the onset of slow growth and walking difficulties. The short stature becomes more prominent with age and the hands and feet appear short and wide. Joint laxity is a general clinical feature, but predominantly affects the hands. Defective epiphyseal growth causes early arthrosis. The limb deformation is caused by metaphyseal lesions. Genetic transmission is autosomal dominant, but most isolated cases are due to de novo mutations. The disorder is caused by small mutations or deletions in the COMP gene (19p13.1) coding for the cartilage oligomeric matrix protein. Diagnosis is made on the basis of epiphyseal and metaphyseal anomalies detected on radiographs during the second year of life. The principle differential diagnosis is achondroplasia, the meaning of the word (a=without; chondro=cartilage and plasia=development), literally means "without cartilage formation," but the craniofacial anomalies present in this disorder are absent in patients with pseudoachondroplasia and radiographic findings differ significantly. Forms of multiple epiphyseal dysplasia may also be included in the differential diagnosis. Genetic counseling may be proposed and the recurrence risk is 50%. Prenatal diagnosis is feasible if the mutation has been detected in an affected parent. Treatment is based on physiotherapy, management of the spinal deformation and corrective orthopedic surgery. Intensive physical activity should be avoided.