Endocrine Abstracts

Introduction: Osteopetrosis is a rare hereditary disease caused by defective osteoclast differentiation or function. Hematopoietic stem cell transplantation (HSCT) is a potentially curative treatment for some forms of osteopetrosis. HSCT is usually performed in infancy. Currently there is also experience of HSCT for osteopetrosis in adults¹. In this clinical case we describe the follow-up of a patient treated with HSCT¹ at the age of 28.

Clinical case: This male patient was diagnosed with osteopetrosis at the age of 5. He has one affected and one healthy sibling. His weight at birth was 4000 g and height 51 cm. He had a developmental delay (he learned to walk at the age of 3). A CA2 mutation (Chr8:86389420 C>G p.Y193X) was revealed. Due to severe anemia and thrombocytopenia the patient required multiple blood transfusions. He also suffered from multiple low-traumatic fractures (clavicle, shoulder, multiple hip, tibia and fibula fractures). Secondary adrenal insufficiency was diagnosed due to extensive bone growth including sella turcica and the patient required hydrocortisone 10-15 mg per day. At the age of 26 his BMD was aboveaverage +6.0 SD Z-score lumber spine and + 5.1 SD Z-score Total Hip. At the age of 28 the patient underwent HSCT¹. He was re-examined in our clinic at the age of 30 with height 147.5 cm; weight −54 kg with significant improvement in his clinical presentation: Hb −123 g/l, thrombocytes −134 × 10⁹ cells/l (152–372 × 10⁹ cells/l), without any low-traumatic fractures, he did not require treatment for secondary adrenal insufficiency anymore: urinary free cortisol −126,9 nmol/24 h; morning cortisol – 352 nmol/l. CT of the head revealed basal ganglia calcifications and thickening of the bones of the facial skeleton, temporal and sphenoid bones.

Conclusion: HSCT was beneficial, leading to the reversal of most dangerous osteopetrosis complications in an adult patient with moderate severity osteopetrosis.

Reference

1. Stepensky P, Grisariu S, Avni B, Zaidman I, Shadur B, Elpeleg O, Sirin M, Hoenig M, Schuetz C, Furlan I, Beer M, von Harsdorf S, Bunjes D, Debatin K-M & Schulz AS. Stem cell transplantation for osteopetrosis in patients beyond the age of 5 years. Blood Adv, 2019 26 862–868.