Pyknodysostosis- A Challenging Diagnosis

Abstract

We report a case of a 7-year-old boy presented to us with short stature, born at full term by SVD with an immediate cry and a birth weight of 03 kg, breast-fed for 2 years. There are no apparent signs of development delay. By the age of two, the mother was concerned about physical and developmental delays.
 The patient had a male sibling with a history of repeated fractures and sensorineural hearing loss, labelled osteopetrosis.
 EXAMINATION:
 
 An active male child of 95cm and 12 kg falls below the 3rd centile.
 He had frontal bossing, mildly hypoplastic maxillae, a wide open fontanelle, and sutural diastasis.
 
 INVESTIGATIONS:
 
 Complete Blood Count, Thyroid profile, Serum Calcium, Phosphorus and Alkaline Phosphatase. All normal.
 A skeletal survey showed an increase in bone density. Sutural diastasis, multiple Wormian bones, thickening of the Calvaria, thickening of long bones with medullary sparing, and spool deformity of vertebral bodies.
 
 DIFFERENTIAL DIAGNOSIS
 
 Pyknodysostosis
 Hypothyroidism
 Osteopetrosis
 
 CONCLUSION:
 Additional X-rays, including the mandible, showed an obtuse angle, the clavicle was laterally deficient, and the hand showed acro osteolysis. The patient was diagnosed with a rare case of pyknodysostosis.