Pseudohypoparathyroidism
| A | Pseudohypoparathyroidism | |
| B |
Hyperparathyroidism |
|
| C |
Hyperthyroidism |
|
| D |
Hypoparathyroidism |
Hypophosphatemia is seen in:
| A |
Pseudohypoparathyroidism |
|
| B |
Hyperparathyroidism |
|
| C |
Hyperthyroidism |
|
| D |
Hypoparathyroidism |
Answer is B (Hyperparathyroidism):
Hyperparathyroidism is typically associated with hypophosphatemia.
Primary Hyperparathyroidism is associated with Hypophosphatemia and Hypercalcemia while Secondary Hyperparathyroidism is associated with Hypophosphatemia and Hypocalcemia.
Hyperthyroidism is typical associated with normal phosphate levels
Hypoparathyroidism and Pseudohypoparathyroidism are associated with Hyperphosphatemia
| A | Low Serum PTH | |
| B |
Low Serum calcium |
|
| C |
High Serum Phosphate |
|
| D |
Albreight’s Hereditary osteodystrophy |
Answer is A (Low Serum PTH):
Pseudohypoparathyroidism
It is a condition associated primarily with resistance to the parathyroid hormone.
Those with the condition have a low serum calcium and high phosphate, but the parathyroid hormone level (PTH) is appropriately high (due to the low level of calcium in the blood). Its pathogenesis has been linked to dysfunctional G Proteins.
Types include:
| Type | Description | |||||
|---|---|---|---|---|---|---|
| Type 1a | Has a characteristic phenotypic appearance (Albright’s hereditary osteodystrophy), including short fourth and fifth metacarpals and a rounded facies. It is most likely an autosomal dominant disorder. It is also associated with thyroid stimulating hormone resistance. | |||||
| Type 1b | Lacks the physical appearance of type 1a, but is biochemically similar. It is associated with a methylation defect. | |||||
| Type 2 | Also lacks the physical appearance of type 1a. Since the genetic defect in type 2 is further down the signalling pathway than in type 1, there is a normal cAMP response to PTH stimulation despite the inherent abnormality in calcium regulation. |
| A |
Pseudohypoparathyroidism |
|
| B |
Hypophophatasia |
|
| C |
Hyperparathyroidism |
|
| D |
Osteomalacia |
Answer is A (Pseudohypoparathyroidism):
The presence of hyperphosphatemia (Serum phosphate) along with characteristic brachydactyly suggests the diagnosis of pseudohypoparathyroidism.
Pseudohypoparathyroidism
- This is a hereditary disorder associated with symptoms and signs of hypoparathyroidism despite an elevated PTH level (pseudohypoparathyroidism)
- This is produced as a result of deficient end organ response to PTH.
| A | Dystrophic calcification | |
| B |
↑ed Ca2+ |
|
| C |
↑ed PO4 |
|
| D |
↑ed PTH |
Answer is D ( ↑ed PTH):
Pseudohypoparathyroidism is associated with elevated PTH and signs of ineffective PTH action
The response of urinary cAMP to PTH is decreased/normal and Heterotopic ossification may be characteristically seen.
Raised calcium and phosphorous seen in:
| A | CRF | |
| B |
Vitamin D intoxication |
|
| C |
Hyperparathyroidism |
|
| D |
Pseudohypoparathyroidism |
Answer is B (Vitamin D intoxication):
Vitamin D intoxication is associated with both hypercalcentia and hyperphosphatemia
Chronic Renal Failure is associated with hyperphosphatemia and hyporcalcemia Hyperparathyroidism is associated with hypercalcemia and hypophosphatemia Pseudohypoparathyroidism is associated with hypocalcemia and hyperphosphatemia
Causes of Hyperphosphatemia
I. Impaired renal phosphate excretion
A. Renal insufficiency
B. Hypoparathyroidism
- Developmental
- Autoimmune
- After neck surgery or radiation
- Activating mutations of the calcium-sensing receptor
C. Parathyroid suppression
1. Parathyroid-independent hypercalcemia
- Vitamin D or Vitamin A intoxication
- Sarcoidosis, other granulomatous disease
- Immobilization, osteolytic metastases
- Milk-alkali syndrome
2. Severe hypermagnesia or hypomagnesemia
D. Pseudohypoparathyroidism
E. Acromegaly
F. Tumoral calcinosis
G. Heparin therapy
II. Massive extracellular fluid phosphate loads
A. Rapid administration of exogenous phosphate (intravenous, oral, rectal)
B. Extensive cellular injury or necrosis
- Crush injuries
- Rhabdomyolysis
- Hyperthermia
- Fulminant hepatitis
- Cytotoxin therapy
- Severe hemolytic anemia
C. Transcellular phosphate shifts
- Metabolic acidosis
- Respiratory acidosis
| A | CRF | |
| B |
Pseudohypoparathyroidism |
|
| C |
Vit. D deficiency |
|
| D |
a and b |
Answer is A and B (CRF and Pseudohypoparathyroidism):
CRF and Pseadohypoparathyroidism are associated with Hypocalcemia and Hyperphosphatemia
Hypocalcemia with Hyperphosphatemia:
- Chronic Renal Failure
- True Hypoparathyroidism
- Pseudo hypoparathyroidism
- Tumor lysis syndrome
- Rhabdomyolysis
| A | Bone metastasis | |
| B |
Sarcoidosis |
|
| C |
Pseudohypoparathyroidism |
|
| D |
Hyperparathyroidism |
Ans. C i.e. Pseudohypoparathyroidism
Pseudohypoparathyroidism presents with hypocalcemia, normal to raised PTH, normal 25-(OH)D, and decreased 1,25-(OH),D
