Abstract
Background: Short-rib thoracic dysplasia (SRTD) and Joubert syndrome (JS) are rare genetic ciliopathies, both patients can manifest cerebellar malformation and variable developmental delays. However, neither could be easily diagnosed during pregnancy due to limited fetal phenotype. Here, we investigated a fetus with short limbs, polydactyly initially and uncovered a compound heterozygous pathogenesis through whole exome sequencing (WES).Results: Merely short limbs and polydactyly of the fetus were detected during second trimester of gestation. Two variants (c.3940+1G>A and c.3303G>A), affecting splicing of KIAA0586 gene, were identified from amniocytes through WES. The presence and effect of these mutations were further validated on DNA and RNA level through Sanger sequencing. More intensive fetal monitoring was applied; deformed cerebellar malformation and restricted thoracic cage of the fetus were additionally uncovered. Conclusion: Herein, we discovered a genetic pathogenesis of KIAA0586 gene associated with SRTD and/or JS in a fetus with mild ultrasound anomalies initially. With the information of prenatal WES and distinct phenotypes of the fetus uncovered by imaging examination, we could reach more accurate clinical diagnosis and provide valuable prognosis information for parents.
Identification of two novel pathogenic variants of PIBF1 by whole exome sequencing in a 2-year-old boy with Joubert syndrome
