Holoprosencephaly with multiple anomalies of the craniofacial bones-an autopsy report

Alobar Holoprosencephaly Associated with Meningomyelocoele and Omphalocoele: An Unusual Coexistence

Holoprosencephaly is a rare congenital disorder which results from failure of cleavage or incomplete differentiation of the forebrain structures at various levels or to various degrees. Depending on the degree of involvement, it is classified into 4 types: Alobar, Semilobar, Lobar and Middle interhemispheric fusion variant. A male child was born to 28-year-old female at 34 weeks of gestation. The mother on antenatal follow-up was detected to have a fetus with multiple congenital anomalies on Ultrasonography (USG) done at 34weeks of gestation. The baby died after 12 hours of birth. A complete autopsy was performed. On external examination, multiple congenital anomalies were seen including cleft lip and palate, absent nasal bridge, proptosis of right eye, micropenis, left undescended testis, bilateral rocker bottom feet, omphalocele and sacral meningomyelocele. Internal examination of the brain revealed hydrocephalus and features of alobar holoprosencephaly. This case is presented for its rarity. In addition, it is unusual for a fetus with alobar holoprosencephaly to survive till term as this is the most severe type. Though facial malformations are usually present in a case of holoprosencephaly, its association with sacral meningomyelocele and omphalocele has rarely been described in literature.

The human brain and face: mechanisms of cranial, neurological and facial development revealed through malformations of holoprosencephaly, cyclopia and aberrations in chromosome 18

The study of inborn genetic errors can lend insight into mechanisms of normal human development and congenital malformations. Here, we present the first detailed comparison of cranial and neuro pathology in two exceedingly rare human individuals with cyclopia and alobar holoprosencephaly (HPE) in the presence and absence of aberrant chromosome 18 (aCh18). The aCh18 fetus contained one normal Ch18 and one with a pseudo-isodicentric duplication of chromosome 18q and partial deletion of 18p from 18p11.31 where the HPE gene, TGIF, resides, to the p terminus. In addition to synophthalmia, the aCh18 cyclopic malformations included a failure of induction of most of the telencephalon - closely approximating anencephaly, unchecked development of brain stem structures, near absence of the sphenoid bone and a malformed neurocranium and viscerocranium that constitute the median face. Although there was complete erasure of the olfactory and superior nasal structures, rudiments of nasal structures derived from the maxillary bone were evident, but with absent pharyngeal structures. The second non-aCh18 cyclopic fetus was initially classified as a true Cyclops, as it appeared to have a proboscis and one median eye with a single iris, but further analysis revealed two eye globes as expected for synophthalmic cyclopia. Furthermore, the proboscis was associated with the medial ethmoid ridge, consistent with an incomplete induction of these nasal structures, even as the nasal septum and paranasal sinuses were apparently developed. An important conclusion of this study is that it is the brain that predicts the overall configuration of the face, due to its influence on the development of surrounding skeletal structures. The present data using a combination of macroscopic, computed tomography (CT) and magnetic resonance imaging (MRI) techniques provide an unparalleled analysis on the extent of the effects of median defects, and insight into normal development and patterning of the brain, face and their skeletal support.