We report on a patient homozygous for a novel 1-bp deletion in ENPP1 that presented with GACI evolving towards HR associated with a mixed hearing loss (both labyrinthine and conductive) diagnosed at 9 days of life that evolved towards profound labyrinthine deafness.
Inactivating mutations of phosphate-regulating gene with homologies to endopeptidases on the X chromosome, dentin matrix acidic phosphoprotein 1, and ectonucleotide pyrophosphatase/phosphodiesterase 1 are associated with X-linked hypophosphatemic rickets, autosomal recessive hypophosphatemic rickets 1, and autosomal recessive hypophosphatemic rickets 2, respectively.