Abnormal posterior brain and molar tooth sign in a fetus with Joubert syndrome at 11 – 13 weeks – new gene mutation discovered: Case report

Purpose: Joubert syndrome (JS), a rare autosomal recessive disorder, is characterized by the molar tooth sign on an axial magnetic-resonance-imaging (MRI). This abnormality results from a complex brainstem malformation and co-occurs with agenesis/hypoplasia of the cerebellar vermis, that leads to an abnormal enlargement of the fourth ventricle (4V). The adverse outcome of JS is characterized by episodes of hyperpnea, abnormal ocular movement, hypotonia, ataxia and developmental delay. Variable features, including cystic kidneys have led to a broader classification, such as JS and related disorders. Results: We d…