Background. Hypophosphatemic rickets (HR) is a rare disease caused by several genetic mutations in factors that cause an increase in fibroblast growth factor 23 (FGF23), and renal phosphate transporters. ENPP1 (ectonucleotide pyrophosphatase / phosphodiesterase 1) mutations cause autosomal recessive inheritance hypophosphatemic rickets type 2.

Case. In our study, we present a novel mutation in the ENPP1 gene detected in 4 siblings in a single family.

Conclusion. Our findings can be applied to further understand molecular pathogenesis and to establish a correlation between genotype and phenotype for HR.

Keywords: ENPP1 gene, hypophosphatemic rickets, novel mutation