Prenatal Visualization of Cebocephaly with a Prominent Nose in a Second-trimester Fetus with Alobar Holoprosencephaly and Trisomy 13

A 39-year-old, gravida 7, para 3, woman was referred to the hospital at 18 weeks' gestation because of advanced maternal age.Initial two-dimensional (2D) ultrasound revealed alobar holoprosencephaly (Figure 1), congenital diaphragmatic hernia, and endocardial cushion defect.Level II 2D ultrasound showed a prominent nose, a large common nasal cavity, absence of nasal septum, and micrognathia (Figure 2).The nasal length measured 18 mm, and the external nasal diameter measured 25 mm.Three-dimensional (3D) ultrasound (Voluson 730D; Medison, Seoul, Korea) demonstrated hypotelorism, a single nostril, and a prominent nasal bridge (Figure 3).The diagnosis of cebocephaly was established.Genetic amniocentesis revealed a karyotype of 47,XY, +13.Quantitative fluorescent polymerase chain reaction using polymorphic small tandem repeat markers specific for chromosome 13 showed that the aneuploidy arose from nondisjunction in maternal meiosis II.The parents opted to terminate the pregnancy.The findings at autopsy were consistent with the prenatal diagnosis (Figures 4 and5).We have presented the prenatal visualization of a prominent nose and a large common nasal cavity associated with trisomy 13 and cebocephaly.Prenatal sonographic diagnosis of nasal malformations has been well