Bone Abstracts

Background: Periosteal reaction can be a manifestation of various underlying medical conditions, including tumor, infection, trauma, metabolic or genetic diseases.

Presenting problem: A 2 year-old male presented for evaluation of periosteal bone formation in symmetrical distribution of proximal humerus, radius, ulnar, femur, and clavicles, noted after having persistent fussiness, irritability and inability to bear weight and use arms for 3 weeks. He had a complex medical history: 30 week prematurity, hiatal hernia (post repair), intestinal malrotation, and mild cardiac left outflow tract obstruction with mild left ventricular hypertrophy. His feeding was elemental formula via gastrojejunostomy tube.

Clinical management: He had normal serum calcium, phosphorus, alkaline phosphatase, CRP, LDH, vitamin D, and PTH levels. Vitamin C was elevated at 138 μmol/l (normal 23–114), thus ruling out scurvy. Coagulation studies and vitamin A were normal. Abdominal and chest CT scan obtained due to concern for underlying malignancy demonstrated tortuosity and ectasia of aorta. This finding in addition to his past medical history raises suspicion of arterial tortuosity syndrome (ATS). DNA sequencing revealed homozygous mutation in the SLC2A10 gene, confirming ATS. He had very low serum copper (<10 μg/dl; normal 75–153) and ceruloplasmin levels (<7 mg/dl; normal 21–53), indicating copper deficiency. He was treated with one intravenous copper infusion followed by daily enteral copper. Serum copper and ceruloplasmin levels repeated one month later were normal, while gradual clinical improvement in bone pain was noted, suggesting that the skeletal changes were attributed to copper deficiency. Repeat bone radiograph 1 month after treatment showed a more exuberant maturing periosteal new bone formation along the proximal to mid femur and tibia, suggesting bone healing.

Discussion: Copper deficiency impairs bone collagen and elastin integrity, thereby manifesting as metabolic bone disease, the work up of which led to diagnosis of ATS in this patient. Periosteal reaction has not been reported in ATS, a rare connective tissue disease that can have skeletal abnormalities. It is unclear whether copper deficiency is solely secondary to malabsorption in the jejunum or may be associated with ATS due to loss of glucose transporter 10 that may have an indirect role in copper metabolism.

Disclosure: The authors declared no competing interests.