Targeted syndrom under study

Williams-Beuren syndrome


We aim  to investigate the natural history of adult patients with Williams-Beuren syndrome with regard to the vitamin D and calcium metabolism and (patho)physiology. The current treatment algorithm recommends not to supplement vitamin D in adults with Williams-Beuren because there have been cases of hypercalcemia in children. However, adult patients often have osteopenia or osteoporosis and a vitamin D deficiency and would therefore benefit from vitamin D (and even calcium) supplementation. We aim to analyse adult patients with Williams-Beuren syndrome and asses the prevalence of vitamin D deficiency, of osteopenia/osteoporosis, of  hypercalcemia (and its underlying pathophysiology), and whether or not supplementation of vitamin D (or calcium) is safe and effective in adults with WBS.

Coordinating clinicians/researchers

Dr. Laura de Graaff, Associate Professor Internal medicine for Rare Genetic Syndromes – ; (Trui van Essen, PhD-student, MD),


Erasmus Medical Center, Rotterdam, the Netherlands

Specific requirements beyond clinical data and genotype data sharing:

  • Re-analysis of DNA samples: No
  • Resampling of patients: No
  • Linked to a translational/basic research project: No