Jacobsen Syndrome With White Matter Abnormalities: A Case Report and MRI Follow-Up.

Jacobsen syndrome (JBS) is a rare genetic disorder caused by a terminal deletion on chromosome 11q. It is associated with craniofacial dysmorphisms, congenital anomalies, hematological abnormalities, and neurodevelopmental delays. White matter abnormalities (WMAs) are a less commonly reported feature of JBS, with limited cases documenting their progression via MRI follow-ups. This case report highlights a neonate with JBS presenting with a WMA and correlates the imaging findings with clinical improvement. We report the case of a female neonate born at 37 weeks of gestation with multiple congenital anomalies. She presented with jaundice, respiratory distress, thrombocytopenia, and a systolic murmur. Echocardiography revealed an atrial septal defect and a ventricular septal defect. Dysmorphic features included low-set ears, a depressed nasal bridge, and a prominent philtrum. The patient exhibited left-sided sensorineural hearing loss, hypotonia, and developmental delays. Genetic testing confirmed a terminal deletion at 11q24.1q25, consistent with JBS. The initial MRI demonstrated unmyelinated white matter in the parieto-occipital lobes without structural abnormalities. Ten months later, a follow-up MRI revealed significant improvement in white matter myelination, which correlated with improved developmental and psychomotor outcomes. WMAs in JBS are believed to result from intra-myelinic edema associated with deletions in genes such as HEPACAM/GlialCAM. Early MRI and serial imaging can document evolving WMAs in JBS and may correlate with clinical improvement, and multidisciplinary follow-up is recommended.