Holoprosencephaly in identical twin neonates: An extremely rare case report

Abstract

Abstract: Holoprosencephaly (HPE) is a rare congenital brain malformation which results from complete or incomplete separation of the forebrain and diencephalon or horizontal separation of the optic and olfactory structures. The septum pellucidum is always absent and patients usually presentwith gross facial abnormality. HPE has an incidence of 1 in 10,000-16,000 births. It is quite uncommon in twin gestations, and when it occurs, usually only affects one of the twins. This study is however presenting the occurrence of HPE in presumably identical set of twins. The twins were a product of assisted reproduction (IVF) and uneventful pregnancy: they were delivered preterm and of low birth weight. Twin one was microcephalic and had facial hypoplasia, while twin two had an associated hydrocephalus. Both were hypoglycaemic. Chest radiographs and abdominal ultrasound scans were normal. Echocardiography showed mid-muscular ventricular septal defect in twin two. Brain CT scans showed semi-lobar holoprosencephaly in both twins, with hydrocephalus in twin two. This case report is being made to document an extremely rare occurrence of holoprosencephaly in both identical twins who were products of assisted reproduction.

Keywords: Holoprosencephaly, identical, twin, preterm, assistedreproduction, semi-lobar