Connect with a community
of support for X-linked
The XLH network is a global patient support organization for people with XLH, parents, and caregivers. The website contains educational resources about XLH for patients and medical professionals.
GARD maintains a list of rare diseases and related terms to help people find reliable information about their disease.
NORD is a patient advocacy organization dedicated to individuals with rare diseases and the organizations that serve them.
A protein that is made by the immune system or a protein that is modified in a lab to recognize and block a target that threatens the body’s normal function.
The beginning of a study, before patients are given any treatment.
A protein that plays a role balancing the amount of phosphorus in the body. In XLH, the activity of FGF23 is abnormally increased, throwing off the balance of phosphorus.
Low levels of phosphorus in the blood.
A statistic that estimates the mean after adjusting for the effect of other variables in a study.
Distortion or misshaping of the legs (eg, bowing).
An average; a number that represents the central value of a set of numbers.
A process where minerals like phosphorus are deposited in the bone, causing the bone to harden.
A rate describing how fast the starting component of bone (osteoid) is made compared to how fast minerals are deposited to create actual bone. In XLH, mineralization lag times are long, causing abnormalities in the process of bone mineralization.
A starting component for building bone where minerals have not yet been deposited; an unmineralized component of bone.
A ratio of unmineralized bone to mineralized bone. In XLH, this ratio is large, pointing to a greater presence of unmineralized bone.
Amount of unmineralized bone.
A softening and weakening of the bones in children and adults caused by deficiencies in vitamin D, calcium, or phosphate. Also, called rickets in children.
A mineral that is important for proper bone development and repair.
A harmless pill, medicine, or procedure that has no therapeutic effect. In Study 3 of adults with XLH, placebo refers to a saline injection.
A kind of fracture where the bone thickens at the site of an injury but is not completely broken.
A way to measure the extent of healing of rickets. This score uses a 7-point scale to rank the healing of rickets and can range from -3 = severe worsening to 0 = no change to +3 = near/complete healing. An RGI-C global score of ≥+2.00 means a substantial healing of rickets was achieved after treatment.
A softening and weakening of the bones in children caused by deficiencies in vitamin D, calcium, or phosphate. Also, called osteomalacia in adults.
Amount of phosphorus in the blood.
A way to measure changes in the severity of rickets. This score uses a 10-point scale to rank the severity of rickets from 0 (normal) to 10 points (severe). A lower score means reduced severity of rickets. This score is complementary to RGI-C.