So, today’s plan was to talk about aging with XLH, but I ended up with just a big jumble of vague thoughts, a bunch of questions, and no answers.
The biggest question I still have is the one that was raised in a blog post I stumbled across, about a different rare disease here: Are my physical/emotional challenges the natural effects of aging, or are they unique to (or worsened by) XLH?
The problem, of course, is that no one knows, because there’s no data. And there isn’t even that much anecdotal evidence. There are a few stories about the progression of symptoms and disability in the Voice of the Patient report, especially from one speaker (see page 15) who laid out the progression by decade of her life. But that’s about it in the literature.
I know what my progression has been like, and I know the trajectory slowed once I started on burosumab, but there’s so much I don’t know. For one thing, it’s well-established that the severity of symptoms is extremely variable in the XLH community, so presumably the nature, extent, and rate of progression will be variable too. For another, as a spontaneous case, I don’t have anything in the way of family health history, which might offer me some guidance if my symptoms/severity were similar to that of an older generation. And in yet another complication for understanding the progression, a lot of our symptoms overlap with natural aging, e.g., arthritis, stiffness, and fatigue.
Normally, when I don’t know something about my health, I go do a bunch of reading, get some answers, and figure out an action plan. But the problem with questions about aging with XLH is that there’s pretty much nothing to read, and no answers anywhere. I would look to other rare disorders (or even common disorders), but you know what? There’s no information about aging with those conditions either! The gist of the only journal article I could find on the topic, “Aging and rare diseases: from epidemiology to a call to action” is that there’s no data, and barely even any discussion!
So, once again, I’m back to bemoaning the lack of a comprehensive natural history study of XLH. The rate of symptom progression and the most common risks of aging with XLH could be extracted from that data eventually, but even if we started a natural history study today, it would likely be ten years or more before we’d have any truly useful information.
Yeah, not exactly an upbeat conclusion, but it’s all I’ve got for you today. Oh, except if you really want to be down in the dumps (or if you’re more of a glass-half-full sort, if you want to be reminded that your life is relatively good and could be a lot worse), go check out this case report, which demonstrates exactly what the International XLH Alliance was talking about last week—the ongoing disparities in access to effective medical community based on geography and financial means. “Delayed Diagnosis of Probable X-Linked Hypophosphatemia Revealed by a Femoral Fragility Fracture in a 33-Year-Old Man.” Not only was his diagnosis delayed (along with what seems a likely diagnosis for his mother and sister), but he doesn’t have reliable access to the old, marginally effective treatment, let alone modern, effective treatment.
I’ll be back next week with, I hope, more answers than questions, and maybe even a vision for a better future for our community!
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Please note that the author is a well-read patient, not a doctor, and is not offering medical or legal advice.
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