Prenatal Detection of Mosaic Trisomy 14 Secondary to Sonographic Findings

Mosaic trisomy 14 or partial trisomy 14 is a rare genetic abnormality that occurs when only a portion of cells have an additional copy of chromosome 14. It has a female prevalence of 3:1 and is associated with a wide range of related disorders. In this case, severe polyhydramnios because of borderline micrognathia was correlated to the diagnosis of mosaic trisomy 14. Early sonographic detection of associated findings can prompt the genetic testing required for diagnosis. Combining sonography and genetic testing leads to an accurate diagnosis, proper management, and postnatal planning for the patient.