Variable Expressivity and Response to Bisphosphonate Therapy in a Family with Osteoporosis Pseudoglioma Syndrome.

BACKGROUND: Osteoporosis pseudoglioma syndrome (OPPGS) is a rare autosomal recessive genetic disorder characterised by congenital blindness and osteoporosis, caused by biallelic mutations in the LRP5 gene. CASE CHARACTERISTICS: A consanguineous family with four OPPGS-affected members with variable expressivity. OBSERVATION: A novel homozygous missense pathogenic variant (c.3709C>T) was identified in the LRP5 gene. Good response to biphosphonate therapy was observed in all affected members. MESSAGE: This case highlights the importance of screening for osteopenia in a case of familial exudative retinopathy, for early institution of bisphosphonate therapy.