Abstract
OBJECTIVE: To diagnose and explore the genetic cause of Joubert syndrome (JS) in a fetus. METHODS: Prenatal ultrasound and magnetic resonance imaging (MRI) examinations were performed, and genetic analysis was conducted using targeted next-generation sequencing (NGS) and Sanger sequencing. RESULTS: Prenatal ultrasound and MRI examinations showed cerebellar vermis hypoplasia and molar tooth sign (MTS); hence the fetus was diagnosed with JS. Further genetic analysis revealed a known missense variant (c.3599C>T, p.A1200V) and a novel missense variant (c.3857G>A, p.R1286H) in the C5orf42 gene of the fetus. CONCLUSION: Our study provides insights into prenatal and early diagnosis of JS and expands the variation spectrum of C5orf42 gene.