A case of early diagnosis of alobar holoprosencephaly from Pakistan: importance of prompt prenatal imaging

Holoprosencephaly (HPE) is a rare congenital condition encompassing incomplete midline cleavage of the prosencephalon and associated craniofacial abnormalities. We report a rare case of a 34-year-old Memon woman, gravida 3 para 2, with no known comorbidities or exposure to teratogens, who presented for her 12-week scan which revealed a single alive fetus having an absent falx cerebri with fused thalami, a single large posterior ventricle, and facial anomalies suggestive of alobar HPE. A follow-up ultrasound showed abnormally fused portions of the brain and a high amniotic fluid index (AFI), indicating polyhydramnios. The fetus had intrauterine death at 7 months of gestation. This case highlights the importance of early prenatal diagnosis of alobar HPE, the most severe form, using transabdominal ultrasonography (USG) and transvaginal USG. Prompt prenatal imaging is crucial for early diagnosis of alobar HPE, enhancing antenatal care, and facilitating improved family planning strategies to alleviate potential psychological distress due to its poor prognosis. Our documentation of such a rare condition is essential to help create a comprehensive database of similar cases.