Today's post is by Gin Jones, wearing her "member at large" hat, and not on behalf of the entire Board. I'm just sharing some thoughts that keep me awake in the middle of the night. I don't have any answers, but all discovery starts with questions.
There's so much about XLH that isn't known, so many questions to ask researchers to look into. Some of that work has begun, like the Gait, Mobility and Range of Motion Study by our Scientific Advisory Board Chair, Carolyn M. Macica PhD, and her student at Quinnipiac University's Frank H. Netter M.D. School of Medicine, Eva Amenta, who's examining bone mineral composition and tooth structure in XLH patients as a biological surrogate for bone mineral.
What else would I like to see investigated? So many things! To keep the list manageable, I'll start with three topics across a range of symptoms.
First there's hearing loss and tinnitus (ringing in the ears). There's been some speculation that since hearing is a function of small bones in the ear, and our bones are affected in a variety of ways, perhaps we're at risk of hearing loss. Is there a higher incidence of hearing loss and tinnitus among XLH patients, and if so, what's the underlying cause and what can be done to minimize the risk?
What about our diets? We know that our bone problems are not caused by a nutritional insufficiency, like the rickets caused by lack of vitamin D intake. But are there foods that could help (or hurt) our limited ability to mineralize our bones? What about interactions between certain foods and the phosphorus and calcitriol we take?
And finally, I'd love to see more crossing of lines between different conditions. I recently ran across an article on achondroplasia (a form of dwarfism in which the cartilage during early development isn't properly converted to bone, especially in the arms and legs, with resulting short stature), which has a different biochemical cause, but some of the same bone-related symptoms as XLH. Apparently spinal stenosis is common, even in children with achondroplasia, and, as in XLH patients (where the stenosis is frequently seen in adulthood), no one knows exactly why the stenosis occurs. Perhaps researchers could compare notes on the two conditions and get to a better understanding of the biochemical processes involved in bone formation and the calcification of cartilage.
That's enough to think about for one day. If you've got questions you'd like to see researchers answer, please share them with me: GinJones at xlhnetwork.org I could use some new material to gnaw on during my sleepless nights.