Recent studies of the Trp53 mouse mutant showed that exencephaly susceptibility depends on the presence of two X chromosomes, not the absence of the Y.
We have previously shown that the p53 gene plays a crucial role in the development of malformations (exencephaly, gastroschisis, polydactyly, cleft palate and dwarfism) in control and irradiated mouse embryos.
Lack of p53 function in the brain results in tumor formation in the astrocytic and lymphoid lineages and in severe neurodevelopmental diseases, such as exencephaly.