High Ocean, Parathyroid disorders can be genetic as this article shows http://www.ncbi.nlm.nih.gov/pubmed/15133326 so if its in your family, its possible that it is what you have. So you need to get your doctor to test your Calcium and PTH (Parathyroid hormone) levels (there just simple blood tests).
According to the Parathyroid site 90% of doctors dont know how to diagnose it properly, its explained why and how it should be done on this page http://parathyroid.com/diagnosis.htm
The basic gist of it is that Doctors are taught at med school that people with Hyperparathyroidism have high Calcium and high PTH, however this is only true in 75% of cases, 25% will have high Calcium and a PTH that is in the higher end of the normal range, but still normal, most doctors will see results like that and say that PTH isnt high so therefore it isnt Hyperparathyroidism and miss the diagnosis.
Also in some people the Calcium is high but still in the normal range, most doctors will tell the patient that it is fine.
The important thing to remember is that high Calcium suppresses the level of PTH, if you have high Calcium even if it is still just in the normal range, your PTH should be low, if you have a healthy parathyroid. If your Calcium is high or high normal and your PTH is high or high normal then you have parathyroidism.
I hope for your sake this is what it is because it is very treatable.
All the best
Thanks a lot Ric. I will bring this to my endocrinologist next time I see him.