Prenatal diagnosis of Apert syndrome with continuation of pregnancy-a report of two cases.

Background: Craniosynostosis, the premature fusion of cranial sutures, may occur in isolated or syndromic forms. Among syndromic craniosynostoses, Apert syndrome is a rare but significant condition, characterized by a triad of multisuture craniosynostosis, midface hypoplasia, and symmetric syndactyly of the hands and feet. Early prenatal diagnosis is challenging but essential for appropriate counseling and perinatal planning.

Case description: We report two cases of prenatal diagnosis of Apert syndrome, confirmed through molecular genetic testing. In the first case, a 32-year-old secundigravida underwent routine ultrasounds that initially revealed no abnormalities. However, at 29 weeks and 6 days, fetal ultrasound demonstrated brachycephaly, a prominent nasal bone, and bilateral syndactyly of the hands and left foot. Fetal exome sequencing identified a heterozygous pathogenic variant in the FGFR2 gene [c.755C>G p.(Ser252Trp)], confirming Apert syndrome. Delivery occurred at 38 weeks and 4 days by elective cesarean section, with postpartum intensive care and corrective surgery. In the second case, a 33-year-old secundigravida had suggestive ultrasound findings at 22 weeks and 3 days, including a prominent forehead, moderate ventriculomegaly, and hypertelorism. Bilateral syndactyly became evident in subsequent scans. Fetal exome sequencing confirmed the same FGFR2 pathogenic variant. Despite regular follow-up, intrauterine fetal demise occurred at 38 weeks, and delivery was performed via cesarean section.

Conclusions: These cases emphasize the importance of detailed fetal imaging, particularly in the third trimester, and the role of genetic testing in confirming syndromic craniosynostoses. Prenatal diagnosis of Apert syndrome enables early parental counseling, delivery planning, and neonatal management, although prognosis can vary significantly.