Pseudohypoparathyroidism

The stem

This 30year old lady was noted to be short by the polyclinic MO. Would you like to examine her?


Suggested presentation

This young woman is overweight, short, with rounded facies, missing teeth, short fingers and a short neck. She also has shortening of both fourth metacarpals.

The combination of these features suggest the diagnosis of psedohypoparathyroidism type 1a

I would like to elicit Chvostek’ and Trosseau’s sign as she may have hypocalcaemia.

Questions that may be asked

What is the basic abnormality in Type Ia patients?
Ans. There is target organ resistance to the action of parathyroid hormone. The defect occurs proximal to the formation of the second messenger , cAMP

How will you treat this patient?
Ans Acute symptomatic hypocalcaemia can be corrected with infused calcium
Gluconate with cardiac monitoring to prevent hypercalcaemia. For long term
treatment, use of calcium supplements and activated Vitamin D to keep calcium
levels within the normal range. (Activated Vit D eg calcitriol to increase
absorption of Calcium in guts and increased retention in kidneys)

What biochemical test can you do in this patient
Ans. Ellsworth Howard Test. In a normal person, infusion of parathyroid hormone will cause a rise in urinary phosptate and cAMP excretion. In Type I A patients, there is no increase in urinary cAMP or phosphate.

What are other causes of short stature you know of?
Ans Genetic for example familial, achondroplasia, Turners and Noonans and Downs syndrome
Nutritional or general illness during childhood eg low birth weight, congenital heart disease or renal disease

Contributed by Giant Eagle