Prenatal Diagnosis of Isolated Unilateral Limb Length Discrepancy: A Case Report

Abstract We report a case of a 32-year-old primigravida referred at 22 weeks' gestation for evaluation of short long bones. Detailed ultrasonography revealed asymmetric shortening of the left tibia and fibula with otherwise normal fetal growth and anatomy. Genetic evaluation identified a heterozygous likely pathogenic variant not typically associated with skeletal dysplasia. Absence of parental testing limited the interpretation of pathogenicity. Despite a favorable orthopaedic prognosis, the couple opted for termination owing to uncertainty regarding phenotypic expression and psychosocial implications. This case highlights the interpretive challenges of prenatal genetic findings in isolated limb length discrepancy and underscores the importance of multidisciplinary counseling in decision-making.