Endocrine Abstracts

Introduction: Hypophosphatemic rickets is uncommon and is either genetic, usually of the X-linked kind (OMIM 307800)or acquired, often related to underlying malignancy (tumor-induced osteomalacia, TIO). Adult-onset cases of unknown aetiology have been described, although they are uncommon.I report such a case occuring after pregnancy.
Case Report: A 39 year-old Serbian woman developed proximal limb weakness and limb girdle pain 6 months after a normal vaginal delivery of a healthy child. Biochemical evaluation demonstrated hypophosphatemia with secondary hyperparathyroidism. Measurements during pregnancy were normal on three occasions. Plain radiograhs demonstrated Looser's zones in the pubic rami, and an isotope bone scan revealed increased activity at multiple sites. No underlying tumor was demonstrated and there was no family history or clinical features to support a diagnosis of X-linked hypophosphataemia. Treatment was undertaken with calcitriol, oral phosphate and calcium supplementation with good clinical and biochemical response. The occurence of hypophosphatemic rickets occuring after pregnancy has not previously been described and the aetiology is obscure.