MICROANATOMY

Detailed explanation-1: -Familial hypocalciuric hypercalcemia (FHH) causes lifelong hypercalcemia with features that overlap with typical primary hyperparathyroidism (PHPT). The incompleteness of this overlap has led to divergent nomenclatures for FHH.

Detailed explanation-2: -Conclusion: The calcium:creatinine clearance ratio (CCCR) is the consensus biochemical test to differentiate between PHPT and FHH. However, this test is still limited by a considerable indeterminate range, and definitive diagnosis of FHH requires genetic testing.

Detailed explanation-3: -Hyperthyroidism is characterised by high levels of serum thyroxine and triiodothyronine, and low levels of thyroid-stimulating hormone. The main causes of hyperthyroidism are Graves’ disease, toxic multinodular goitre, and toxic adenoma.

Detailed explanation-4: -Primary hyperthyroidism relates to the thyroid gland producing large amounts of hormone due to either uncontrolled growth of hormone-producing functional tissue or by way of an autoimmune process that interferes with the normal feedback control.