Mosaic trisomy 8: Diagnostic approach with fetal MRI as a complement to ultrasonography

Objective: Trisomy 8 mosaicism (MT8) is characterized by intracranial, genitourinary and skeletal system anomalies, congenital cardiovascular disorders, deep palmar and plantar creases, and neoplastic and hematological disorders. In the literature, there are only a few antenatal ultrasound (US) and fetal magnetic resonance imaging (MRI) findings reported for MT8. Case: The fetus whose gestational age was 26 weeks and 4 days was referred for fetal MRI due to corpus callosum agenesis suspected in routine US screening. We are presenting the major and minor MRI findings of the fetus in this case report. Conclusion: Fetal MRI can be used in addition to the antenatal ultrasound to evaluate genetic syndromes such as trisomy 8 mosaicism and to identify additional anomalies which cannot be found in the ultrasound screening.