From Caudal Regression to Wieacker-Wolff Syndrome: The Decisive Role of Postmortem Examination and Exome Sequencing in Revising a Prenatal Diagnosis.

Prenatal detection of bilateral clubfoot should prompt a systematic evaluation for associated anomalies, particularly sacral defects and other lower-limb malformations. Arthrogryposis must also be considered in the differential diagnosis. Importantly, prenatal imaging should be complemented by postnatal assessments, which may, as in the present case, uncover a misdiagnosis with major implications for future pregnancies. This case report illustrated how detailed postnatal investigations led to the revision of an initial diagnosis of caudal regression syndrome to the final, exceptionally rare diagnosis of Wieacker-Wolff Syndrome. Such diagnostic correction carries substantial consequences for genetic counseling. Wieacker-Wolff syndrome, also referred to as intellectual disability, developmental delay, and contractures syndrome, is a severe neurodevelopmental disorder characterized by arthrogryposis and intellectual disability. It is inherited in an X-linked manner, either dominant or recessive, and is caused by pathogenic variants in the ZC4H2 gene.