Veluchamy Manikandasamy, Murugan Mariappan
Neonatology, NMC Specialty Hospital, Dubai, ARE.
Radiodiagnosis, Velammal Medical College Hospital and Research Institute, Madurai, IND.
Cureus. 2020 Jul 14;12(7):e9181. doi: 10.7759/cureus.9181.
The holoprosencephalies (HPEs) are a group of disorders that are characterized by a failure of differentiation and midline cleavage of the prosencephalon, which usually occurs between days 18 and 28 of gestation. HPE has been divided into three subcategories based on the structural malformation: alobar, semilobar, and lobar HPE. Middle interhemispheric variant (MIH) or syntelencephaly is also considered as a milder variant of HPE. It is estimated to occur in 1/16,000 live births and 1/250 conceptuses. HPE is caused by genetic factors or environmental factors and teratogens. Clinical presentation depends on the severity of the malformation. Severe cases are usually associated with facial abnormalities like hypertelorism or midline facial clefts. HPE is diagnosed prenatally by ultrasound and MRI. Treatment of HPE is supportive and symptomatic. The clinical outcome depends on the severity of HPE and associated medical and neurological complications.
前脑无裂畸形（HPEs）是一组以原脑分化失败和中线分裂异常为特征的疾病，这种情况通常发生在妊娠第18至28天之间。根据结构畸形，HPE被分为三个亚类：无脑叶型、半脑叶型和脑叶型HPE。中脑间叶变异型（MIH）或融合性全前脑也被认为是HPE的一种较轻变异型。据估计，其在活产婴儿中的发生率为1/16,000，在孕体中的发生率为1/250。HPE由遗传因素、环境因素和致畸剂引起。临床表现取决于畸形的严重程度。严重病例通常伴有面部异常，如眼距过宽或中线面部裂。HPE通过超声和MRI进行产前诊断。HPE的治疗是支持性和对症性的。临床结果取决于HPE的严重程度以及相关的医学和神经并发症。
