Neonatal transient distal renal tubular acidosis in a patient with pseudohypoparathyroidism type 1a

Pseudohypoparathyroidism is characterized by hypocalcemia, hyperphosphatemia and hyperparathyroid hormone (PTH)-emia defined by target organ (kidney and bone) unresponsiveness to PTH. Because the clinical symptoms and hypocalcemia appear when the patients are approximately 3 years of age, the clinical features during early infancy remain unknown. An infant female patient had transient renal tubular acidosis (RTA), which improved only with conservative therapy. Thereafter, the patient exhibited the characteristics of Albright’s hereditary osteodystrophy, including short stature, round and puffy face, obesity, and psychomotor retardation. According to the clinical findings of PTH-resistant hypocalcemia, hyperphosphatemia and hyper-PTH-emia, which simultaneously occurred with growth hormone (GH) deficiency and hypothyroidism, the clinical diagnosis of pseudohypoparathyroidism type 1a was made when the patient was 1 year 8 months of age. This is the first report of a patient with pseudohypoparathyroidism who had neonatal RTA. We herein discuss the basic pathogenesis of the coincidental nature of these two problems. This case report might help to elucidate the clinical features of neonatal patients with pseudohypoparathyroidism type 1a.