Holoprosencephaly: two case reports.

Area of Science:

• Medical Genetics
• Developmental Biology
• Neonatal Neurology

Background:

• Holoprosencephaly (HPE) is a spectrum of congenital brain malformations characterized by the failure of the embryonic forebrain (prosencephalon) to divide properly.
• This condition occurs in approximately 1 in 8,000 live births and is associated with significant morbidity and mortality.
• HPE can range from mild forms with subtle midline defects to severe forms with profound brain and facial abnormalities.

Observation:

• Case 1 describes a fetus diagnosed via ultrasonogram at 29 weeks gestation with alobar holoprosencephaly, proboscis, and cyclopia. The infant was delivered prematurely at 32 weeks gestation, confirming the antenatal diagnosis.
• Case 2 details a premature newborn (29 weeks gestation) presenting with a posterior cranial cavity mass, partially fused thalami, and communicating lateral ventricles, diagnosed as lobar holoprosencephaly with an arachnoid cyst post-autopsy.

Findings:

• Ultrasonography and autopsy confirmed distinct presentations of holoprosencephaly, including severe alobar and less severe lobar forms.
• Associated anomalies such as proboscis, cyclopia, and arachnoid cysts highlight the variable expressivity of HPE.
• The cases underscore the importance of detailed neuroimaging for accurate antenatal and postnatal diagnosis.

Implications:

• Accurate diagnosis of holoprosencephaly is crucial for genetic counseling and family planning.
• Understanding the spectrum of HPE aids in predicting prognosis and managing affected neonates.
• Further research into the genetic and environmental factors underlying HPE can inform preventative strategies and therapeutic interventions.