Hereditary hypoparathyroidism, isolated

Last update: December 6, 2018

Panel testing recommended at Breda Genetics for this condition:

Hereditary hypoparathyroidism, isolated (PTH, GCM2, CASR)

Summary

Hypoparathyroidism is a clinical disorder characterized by hypocalcemia and hyperphosphatemia.

thyroid gland displayed within the neck in its vicinity to trachea

Image 1 – Thyroid gland.

Hypoparathyroidism manifests when parathyroid hormone (encoded by the PTH gene) secreted from the parathyroid glands is insufficient to maintain normal extracellular fluid calcium concentrations (defective synthesis or secretion) or, less commonly, when the hormone is unable to function optimally in target tissues, despite adequate circulating levels (end-organ resistance or inappropriate regulations that result from the activated or antibody-stimulated calcium-sensing receptor – CaSR). Genetically inherited forms of hypoparathyroidism arise from defects of parathyroid gland development, defects in the parathyroid hormone gene (PTH), defects in the calcium-sensing receptor gene, defects in the autoimmune regulator gene, and genetic syndromes.

Pure, nonsyndromic genetic forms of hypoparathyroidism (isolated hereditary hypoparathyroidism) include:

Image of the thyroid (in red) and four parathyroids glands (in yellow)

Image 2- Thyroid and parathyroid glands.

familial isolated hypoparathyroidism (PTH or GCM2 gene mutations)

X-linked form of hypoparathyroidism (as yet unknown gene)

Patients affected by genetic hypocalcemia (with or without with Bartter syndrome, CASR gene mutations) or hypocalciuric hypercalcemia, type I (CASR gene mutations) may also be initially diagnosed with hypoparathyroidism.

Genetic testing strategy

Given the genetic heterogeneity, we recommend proceeding to a next generation sequencing multigene panel based on either exome or genome sequencing.

Panel testing recommended at Breda Genetics for this condition:

Hereditary hypoparathyroidism, isolated (PTH, GCM2, CASR)

References:

OMIM: 146200601198145980307700

emedicine.medscape.com

Posted in Academia, Disease cards, Last Update, Medical Genetics and tagged , , , .

Leave a Reply

Your email address will not be published. Required fields are marked *