The development of pseudohypoparathyroidism. Involvement of progressively increasing serum parathyroid hormone concentrations, increased 1,25-dihydroxyvitamin D concentrations, and 'migratory' subcutaneous calcifications
R. C. Tsang, P. Venkataraman, M. Ho, J. J. Steichen, J. Whitsett and F. Greer
The hormonal changes in the development of pseudohypoparathyroidism ( PSH )
have not, to our knowledge, been previously reported. The male sibling of a
child with PSH was studied for 2 1/2 years. At 1 year of age he had
generalized subcutaneous calcifications that subsequently migrated over his
body. At 3 years of age and over a six-month period, serum calcium levels
fell; serum phosphorus, parathyroid hormone (PTH), and
1,25-dihydroxyvitamin D (1,25-[OH]2D) concentrations increased. There was
no calcemic, phosphaturic, or urinary cyclic adenosine monophosphate
response to PTH. The concentration of serum PTH was suppressed by infusion
of calcium and doubled with edetic acid infusion, indicating that the
parathyroids were sensitive to changes in calcium levels. Thus, increasing
PTH and increased 1,25-(OH)2D concentrations occur in the development of
PSH . Migratory skin calcifications may occur. We speculate that increasing
the serum PTH level reflects increasing compensatory parathyroid production
to overcome a progressive PTH receptor defect and serves, with increased
1,25-(OH)2D concentrations, to prevent severe falls in serum calcium
concentrations in the early stage of the disease.
