Presentation
Admitted to NICU with an abnormal antenatal ultrasound.
Patient Data
Antenatal fetal U/S; 35 weeks gestation shows:
Posterior fossa CSF cystic space communicating with the 4th ventricle with aplastic vermis.
Also, the abdomen shows grossly enlarged both kidneys with echogenic parenchyma and bilateral minimal hydronephrosis.
Transcranial ultrasound showed posterior fossa CSF space with 4th ventricle communication along with aplastic vermis. Differential diagnosis of Dandy-Walker malformation for MRI assessment.
U/S abdomen also revealed enlarged both kidneys with increased parenchymal echogenicity and loss of corticomedullary differentiation along with few cystic changes near the pelvis and tiny few parenchymal cysts the largest not exceeding 8 mm denoting renal cystic disease.
Typical features of Joubert syndrome. Axial T2 and FLAIR sequences showing the "molar tooth sign" of the pons and batwing configuration of the 4th ventricle.
Coronal T2 and sagittal FLAIR sequences showing aplastic cerebellar vermis.
Case Discussion
A 30-year-old female presented to the outpatient clinic for an antenatal check-up at 35 weeks gestation and a history of previous siblings with congenital anomalies (4 siblings). The patient underwent an elective cesarean section.
Postnatal transcranial and U/S abdominal confirmed the findings of the antenatal scan and recommended brain MRI. MRI was done 18 days postnatal and confirmed Joubert syndrome findings.
Joubert syndrome is inheritance usually an autosomal recessive disorder, It affects the brain and may affect other parts of the body like the kidneys and eyes.
It is characterized by cerebellar vermis and brainstem anomalies seen in axial and coronal images with an associated narrowing of the midbrain tegmentum and thickening of the superior cerebellar peduncles resulting in the molar tooth sign with other renal anomalies that are defined as Joubert syndrome type B.
Renal involvement has been described in 30% of patients with Joubert syndrome in the form of cystic dysplasia and is referred to as Dekaban-Arima syndrome.