Sandbox:Nimmi Nath
Overview
Familial hypocalciuric hypercalcemia may be caused by genetic and rarely autoimmune factors. FHH type 1(the most common type of FHH) is caused by mutations in the CASR gene, which codes for the calcium-sensing receptor, CaSR protein. FHH type 2 is caused by mutations of the GNA11 gene,which codes for the alpha subunit of a G protein called G11, which ultimately works with CaSR protein to regulate the calcium levels in the blood. FHH type 3 is caused by mutations in the AP2S1 gene, (adaptor-related protein complex 2, sigma 1 subunit).
Causes
Each subtype of FHH is caused by mutations in the following genes:
- FHH Type 1 - CaSR gene (Chromosome 3q21.1) [1]
- FHH Type 2 - GNA11 gene (Chromosome 19p13.3) [1]
- FHH Type 3 - AP2S1 gene ( Chromosome 19p13.3)[1]
Rarely, Autoimmune Hypocalciuric Hypocalcemia should be suspected in patients with similar presentation but negative mutational analyses of CASR, GNA11, and AP2S1 for familial hypocalciuric hypercalcemia.[2]
References
- ↑ 1.0 1.1 1.2 Hannan, Fadil M; Babinsky, Valerie N; Thakker, Rajesh V (2016). "Disorders of the calcium-sensing receptor and partner proteins: insights into the molecular basis of calcium homeostasis". Journal of Molecular Endocrinology. 57 (3): R127–R142. doi:10.1530/JME-16-0124. ISSN 0952-5041.
- ↑ Miñambres, Inka; Corcoy, Rosa; Weetman, Anthony P; Kemp, E Helen (2020). "Autoimmune Hypercalcemia Due to Autoantibodies Against the Calcium-sensing Receptor". The Journal of Clinical Endocrinology & Metabolism. 105 (7): 2229–2236. doi:10.1210/clinem/dgaa219. ISSN 0021-972X.