Osteoporosis-Pseudoglioma Syndrome is a rare autosomal recessive disorder characterized by severe osteoporosis and eye abnormalities that lead to vision loss. In this study, we report clinical findings and genetic study of two siblings with OPPG. Whole exome sequencing on DNA enriched for exonic regions was performed with SureSelect 38Mbp all exon kit v. 7.0. The two siblings showed different clinical manifestations with OPPG; as the female patient had blindness and severe osteoporosis with multiple fractures, while her older brother was blind with- less severe osteoporosis and no bone fractures. In these patients, a novel homozygous nonsense mutation (c.351G>A) in exon 2 of LRP5 gene (NM_002335) was found, changing Tryptophan 117 to stop codon (p. Trp117Ter). A variety of clinical manifestations of OPPG can be observed in a family despite the same gene mutation. The novel mutation reported in this study expands the spectrum of the underlying OPPG genetic
pathology.