Osteosclerotic bone disorder - Pyknodysostosis

Pyknodysostosis is an autosomal recessive osteoclastic dysfunction characterized by generalized hyperostosis and short stature which has mere 10 cases reported from India out of 133 globally reported cases. This rare disorder is due to defective lysosomal cysteine protease cathepsin K in chromosome 21. A male child of 11 years underwent radiological investigation for stunted growth. Examination revealed less height for age, retarded mandibular growth, dysmorphic facial growth, and proportionately short fingers. Radiological findings showed generalized osteosclorosis, hypoplastic paranasal air sinuses, spool-shaped dorsolumbar vertebral bodies, acro-osteolysis of terminal phalanges, and scalloped acetabulum with increased bone density. Management of child should be aimed at correcting anemia and primary prevention of fractures. The postnatal craniofacial development needs to be monitored. Long-term management should aim at genetic mapping and therapy with bone marrow transplantation.