Here I present: “HOLOPROSENCEPHALY ”, Victor McKusick, Mendelian Inheritance in Man’, 1966. 全息性脑病。
INTRODUCTION.
Holoprosencephaly (HPE) is a cephalic disorder in which the prosencephalon (the forebrain of the embryo) fails to develop into two hemispheres.
Holoprosencephaly (HPE) is the most common structural malformation of the human forebrain and occurs after failed midline cleavage of the developing brain during the third and fourth weeks of gestation. HPE occurs in up to 1 in 250 gestations, but only 1 in 8,000 live births. Classically, 3 degrees of severity defined by the extent of brain malformation have been described. In the most severe form, ‘alobar HPE,’ there is a single ventricle and no interhemispheric fissure. The olfactory bulbs and tracts and the corpus callosum are typically absent. In semilobar HPE,’ the most common type of HPE in neonates who survive, there is partial cortical separation with rudimentary cerebral hemispheres and a single ventricle. In ‘lobar HPE,’ the ventricles are separated, but there is incomplete frontal cortical separation. An additional milder form, called ‘middle interhemispheric variant‘ (MIHV) has also been delineated, in which the posterior frontal and parietal lobes are incompletely separated and the corpus callosum may be hypoplastic. Finally, microforms of HPE include a single maxillary median incisor or hypotelorism without the typical brain malformations.
There is evidence Holoprosencephaly (HPE) is caused by a mutation in the HPE6 gene on cytogenetic location 2q37.1-q37.3 and genomic coordinates 2:230,100,001-242,193,529 . The screenshot of the HPE6 gene bp (base pairs) of DNA sequence length is shown BELOW. Nine (9) other genes besides HPE6 in the 2q37.1-q37.3 cytogenetic location are listed BENEATH. 
| Coordinate | Symbol | Genomic Name. |
| 2:229,357,629 | DNER | Delta-and notch egf-related receptor |
| 2:229,763,837 | TRIP12 | Thyroid hormone receptor interact 12 |
| 2:229,922,503 | FBXO36 | F-box only protein 36 |
| 2:230,100,001 | BDMR | Chromosome 2q37 deletion syndrome |
| 2:230,100,001 | HPE6 | Holoprosencephaly 6 |
| 2:230,100,001 | MYP12 | Myopia 12 |
| 2:230,100,001 | STQTL21 | Stature quantitative trait locus 21 |
| 2:230,165,186 | SP110 | SP110 nuclear body protein |
| 2:230,186,151 | SP140 | Nuclear body protein sp140 |
| 2:230,327,193 | SP140L | Nuclear body protein SP140-like |
