Pseudohypoparathyroidism

This is a rare condition that can easily be diagnosed with the proper diagnostic steps. 

Classic presentation

  • Hypocalcemia (low blood calcium)
  • Hyperphosphatemia (high blood phosphate)
  • Elevated PTH (parathyroid hormone) concentrations with target tissue unresponsiveness to biologic actions of PTH
  • With or without Albright’s Hereditary Osteodystrophy (AHO) phenotype (specific appearance of patient)

houston pseudohypoparathyroidism

History

In 1942 Dr. Albright  described 3 patients with AHO phenotype and laboratory hypocalcemia findings in which the administration of parathyroid tissue extracts did not promote an increase in serum calcium or phosphaturia. This chemistry was basis of hypothesis of parathyroid hormone resistance. The AHO phenotype is a foreshortened 4th or 5th metacarpal (brachydactyly) in 92%, short stature in 76%, Rounded face          in 71%, low IQ in 64%, Obesity in 61%, and subcutaneous calcification in 35%.In 1966, Tashjian et al. demonstrated elevated PTH concentrations in these patients. In 1969, Chase et al.  presented that there was no urinary cAMP generation in patients with PHP and that the pathogenesis of this abnormality should be related to a renal defect in the generation of urinary cAMP by the PTH receptor. Since the 2000’s, Weinstein et al and Levine et al Investigating the molecular/genetic basis of the disease which is based on mutations in PTH- G-protein receptor. Specific mutations in this receptor lead to specific clinical manifestations.




References
Albright F et al. Pseudohypoparathyroidism: an example of Seabright-Bantam Syndrome. The Journal of Clinical Endocrinology & Metabolism Vol. 88, No. 9 4055-4058
Copyright © 2003 by The Endocrine Society. 
Pseudohypoparathyroidism and Mechanisms of Resistance toward Multiple Hormones: Molecular Evidence to Clinical Presentation. Murat Bastepe and Harald Jüppner Endocrinology Vol. 145, No. 12 5459-5464. Minireview: GNAS: Normal and Abnormal Functions Lee S. Weinstein, Jie Liu, Akio Sakamoto, Tao Xie and Min Chen Arq Bras Endocrinol Metab vol.50 no.4 São Paulo Aug. 2006
Williams Textbook Endocrinology Annals of the New York Academy of Sciences. Volume 1068 Page 250 - April 2006. Autosomal-Dominant Pseudohypoparathyroidism Type Ib is Caused by Different Microdeletions Within or Upstream of the GNAS Locus. Harald Juppner et al.
Pediatric Research 53:749-755 (2003). Molecular Analysis of the GNAS1 Gene for the Correct Diagnosis of Albright Hereditary Osteodystrophy and Pseudohypoparathyroidism. Luisa De Sanctis


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