About BeyondXLH

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by Mary Chapman |

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XLH multidisciplinary approach

If you or your child have X-linked hypophosphatemia (XLH), you might want to consider enrolling in the online disease-monitoring program BeyondXLH.

Because XLH is so rare, and its symptoms can vary greatly, it’s difficult to predict how the disease will progress, and what treatments will be best for any one person. BeyondXLH is working to gather more data than researchers have been able to collect thus far.

What is XLH

Mutations in the PHEX gene cause XLH. This results in patients having weakened bones and teeth due to excess excretion of phosphate from the kidneys.

What is BeyondXLH?

BeyondXLH is a longitudinal and observational, online disease-monitoring program run by Ultragenyx Pharmaceutical for people with XLH and other hypophosphatemic disorders in the U.S. and Canada. A collaboration between Yale University and the XLH Network, BeyondXLH asks patients to record their day-to-day symptoms and share some of their medical information.

Its goal is to characterize XLH and related diseases from the patient perspective through a mobile web-based application. Information collected will help clinicians, scientists and patients better understand the impact of XLH and treatment management, and inform future research.

BeyondXLH also promotes the long-term engagement of patients and healthcare providers, and helps to inform newly diagnosed patients and their families. It also provides real-world data on healthcare resources and how they are used.

Who is eligible to enroll in BeyondXLH?

XLH patients of all ages in the U.S. and Canada are eligible to participate in the program. All must have a physician’s diagnosis of XLH or other chronic hypophosphatemic disorder, and must not be using Crysvita (burosumab) through an Ultragenyx-sponsored interventional clinical trial.

What to expect

Following eligibility screening, verification, and agreement to consent, you will register and provide baseline information about your demographics and medical history.

The app will allow you to enter data at scheduled three- to four-month intervals. Every 12 months, you’ll also receive follow-up questions about disease progression.

You will also have the opportunity to log personal milestones associated with the disease at any time. This will allow clinicians and researchers to track disease progression over time.

Participation and data security

There are no restrictions on medications or therapies using during program participation. You will be able to review your own data collected over time, and general reports on your progress. You will also be able to compare your data to de-identified aggregate data.


Last updated: July 31, 2020


X-Linked Hypophosphatemia News Today is strictly a news and information website about the disease. It does not provide medical advice, diagnosis, or treatment. This content is not intended to be a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition. Never disregard professional medical advice or delay in seeking it because of something you have read on this website.