First trimester sonographic findings of alobar holoprosencephaly with cyclopia, proboscis, omphalocele, single ventricle in a fetus with trisomy 13

Alobar holoprosencephaly with cyclopia is a rare lethal congenital anomaly frequently accompanied by other malformations and characterized by large variations in incidence. It is included into the disorders of formation of the structures derived from the "mediobasal prosencephalon". The prosencephalon is the anterior end of the neural tube and consists of the telencephalon which gives rise to the cerebral hemispheres and striatum, and the diencephalon which gives rise to thalamus, hypothalamus globus pallidus and eye. Several malformations showing various severity belong to this category and the the most serious defect from this group of anomalies; prosencephalon has not divided into two parts supposed to become the hemispheres is alobar holoprosencephaly with cyclopia: single eye, absent nose, supraorbital proboscis. We herein present the sonographic and postmortem findings of a 13 weeks fetus with alobar holoprosencephaly with cyclopia and prosbiscus from a 37 year old woman G6 P:5 woman. with no known exposure to teratogens and drugs. Single ventricule and omphalocele were also detected and karyotype analysis revealed trisomy 13.

Keywords

Trisomy 13, holoprosencephaly, cyclopia