Prenatal Ultrasonographic Detection of Bilateral Congenital Cataracts With Concurrent Mosaic Turner Syndrome: A Case Report

We report bilateral congenital cataracts diagnosed prenatally at 22 weeks gestation in a woman with personal cataract history. Prenatal ultrasound revealed asymmetric bilateral lens opacities with complete hyperechogenicity in the right eye and punctate hyperechoic foci in the left eye. Clinical exome sequencing identified a heterozygous frameshift variant c.2604_2605del p.(Thr870PhefsTer46) in the BCOR gene, classified as likely pathogenic with postnatal confirmation. Notably, postnatal genetic analysis revealed mosaic Turner syndrome (mos 46,X,+mar[13]/46,XX[37]), representing a rare concurrent finding. The infant underwent successful bilateral cataract extraction at 1 month. This case demonstrates the value of comprehensive genetic evaluation in prenatal ocular anomaly diagnosis and highlights the emerging recognition of dual molecular diagnoses in clinical genetics.