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Updated: Oct 29, 2025

Assessing Cellular Target Engagement by SHP2 PTPN11 Phosphatase Inhibitors
Published on: July 17, 2020
Autosomal recessive hypophosphatemic rickets type 2 (ARHR2) due to ENPP1-deficiency
Jakob Höppner1, Uwe Kornak2, Kathrin Sinningen3
1Center for Rare Diseases Ruhr CeSER, Ruhr-University Bochum and Witten/Herdecke University, Germany; Department of Pediatrics, St.-Josef Hospital Bochum, Ruhr-University Bochum, Bochum, Germany.
Abstract:
Awareness for hypophosphatemic rickets has increased in the last years, based on the availability of specific medical treatments. Autosomal recessive hypophosphatemic rickets type 2 (ARHR2) is a rare form of hypophosphatemic rickets, which is known to develop in survivors of generalized arterial calcification of infancy (GACI). Both disorders are based on a deficiency of ectonucleotide pyrophosphatase/phosphodiesterase 1 (ENPP1) and present with a high clinical variability and a lack of a phenotype-genotype association. ARHR2 is characterized by phosphate wasting due to elevated fibroblast growth factor 23 (FGF23) levels and might represent a response of the organism to minimize ectopic calcification in individuals with ENPP1-deficiency. This report reviews the recent clinical and preclinical data on this ultra-rare disease in childhood.
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