An unusual case of autonomous hyperparathyroidism in a patient with X-linked hypophosphatemic rickets and Kallmann syndrome.
We are reporting an unusual patient who presented to our medical center at 18 years of age for evaluation of disabling bilateral lower extremity deformity and delayed puberty. Extensive clinical, laboratory, and radiologic evaluation confirmed the coexistence of 2 X-linked inherited disorders, X-linked hypophosphatemic rickets (XLH) and Kallmann syndrome (KS). Treatment with oral phosphate and calcitriol along with intramuscular testosterone injections was initiated. Despite a dramatic response, the course of treatment was complicated by secondary hyperparathyroidism and, 13 years later, by the development of an autonomous parathyroid adenoma that was surgically resected. Furthermore, the coexistence of XLH and KS has not been reported before. We believe that the proximity of the KAL-1 gene (Xp 22.3), involved in the pathogenesis of KS, to the phosphate regulating endopeptidase on the X chromosome gene (Xp 22.1-22.2), involved in XLH, might be responsible for this association.
Nabbout
Lara Al-Khoury
LA
Department of Medicine, Division of Endocrinology and Metabolism, American University of Beirut Medical Center, Beirut, Lebanon.
Salti
Ibrahim S
IS
Choucair
Mahmoud K
MK
D000293:Adolescent; D000469:Alkaline Phosphatase / Q000097:blood; D002118:Calcium / Q000097:blood; D053098:Familial Hypophosphatemic Rickets / Q000097:blood / Q000150:complications* / Q000235:genetics; D040181:Genetic Diseases, X-Linked; D006801:Humans; D006962:Hyperparathyroidism, Secondary / Q000097:blood / Q000209:etiology*; D017436:Kallmann Syndrome / Q000097:blood / Q000150:complications* / Q000235:genetics; D008297:Male; D010281:Parathyroid Hormone / Q000097:blood; D010710:Phosphates / Q000008:administration & dosage / Q000009:adverse effects; D010758:Phosphorus / Q000097:blood; D013997:Time Factors
D010281:Parathyroid Hormone; D010710:Phosphates; D010758:Phosphorus; D000469:Alkaline Phosphatase; D002118:Calcium