We've all experienced it: the doctor who won't listen to the patient. It's not limited to rare disorders like XLH, but it becomes particularly challenging with conditions where there isn't a lot of scientific literature or even consensus, so you can say, "Look, you're wrong. It says so right here."
Sometimes the answer is to fire the doctor and find a new one, but that's not always an option. There may not be another specialist within a reasonable commute radius, or you may just be too beaten down from your health issues that you don't have the energy to fight the inter-personal battle.
So, what else can you do? Doctors aren't necessarily trained on how to talk to patients, so you may need to teach yourself how to talk to them, to increase the chance of them listening to you. Global Genes has a webinar on the topic here:
You might also find their toolkit on a "care notebook" to be useful. Having dates and lab results and other facts right at your fingertips can make your communication effective. Download the tookit here: https://globalgenes.org/toolkits/building-a-care-notebook/carenotebook/
In addition to the sections and materials recommended by Global Genes, consider writing down concise answers for some common questions so you can refer to them as needed and don't get caught tongue-tied when asked. Start with a simple explanation for what XLH is (e.g., a genetic, metabolic, phosphate-wasting disorder that affects bone, teeth and muscle), which is particularly useful when you're seeing a doctor for reasons other than your XLH treatment, like a routine physical. A list of your main XLH-related symptoms (e.g., bone pain, arthritis due to misaligned joints, calcifications, spinal issues, fatigue) can be useful whether you're seeing a specialist or your primary care provider. When you have a lot of issues, it helps the doctor to know which ones are the biggest problems for you. And finally, for a specific appointment, try to identify ahead of time the one particular symptom you're looking to improve (e.g., pain management, reduction in fatigue, increased mobility, improved range of motion), rather than presenting with a whole litany of problems, which can be almost as overwhelming for the doctor as it is for you!
To get your notebook started, consider downloading a copy of each of the Network's brochures to include for easy reference. You can find the main brochure here: http://xlhnetwork.org/about-us/xlh-network-brochure/
and the dental ones here: http://xlhnetwork.org/what-is-xlh/dental-flyers/
There's also a wealth of information at the forum that you can print for your notebook, including research citations you may wish to share with your doctor (or study yourself before talking to your doctor). You can find them in this thread (after you log in): http://vps.xlhnetwork.org/~xlhforum/forum/index.php?board=32.0