Holoprosencephaly (HPE) is a complex human brain malformation resulting from the incomplete separation of the two cerebral hemispheres. There are several different types of holoprosencephaly. In the alobar form, there is no separation between the right and left halves at all. In semilobar HPE, at least some separation of the two halves is present. In the lobar form, most of the brain has separated into right and left sides, though there is incomplete division into the two halves. Facial abnormalities occur in approximately 80% of HPE patients and can include cyclopia, proboscis and cleft lip/palate in the severe form, to a single central maxillary incisor, ocular hypotelorism and nasal abnormalities in the milder forms. HPE is the most common forebrain developmental anomaly in humans with prevalence of 1/16,000 in live borns, an incidence as high as 1:250 in conceptuses. The etiology of HPE is very heterogeneous. It can be caused by environmental or metabolic factors. HPE can also be associated with several defined multiple malformation syndromes or a feature of chromosomal abnormalities. HPE may also be a solitary manifestation (neither chromosomal nor syndromic) and several genes have been reported to be associated with isolated forms of HPE. This panel includes sequence and deletion/duplication analysis of all the listed genes.

6 weeks
CPT Code 
Test Code 
Test Methods 
Deletion/Duplication analysis
Specimen Types Accepted 
Cultured Cells
Extracted DNA
Additional Information 
Any gene in the Holoprosencephaly Panel can also be ordered individually. Please contact us directly for cost and CPT code information.