Most people act abnormal even when they look healthy. There’s a chance that their brain developed without the cerebellum!
Medically know as cerebellar agenesis and believed to be caused due to a mutation of the PTF1A gene.
Cerebellar agenesis is a rare condition in which a brain develops without the cerebellum. The cerebellum controls smooth movement, and when it doesn’t develop, the rest of the brain must compensate, which it cannot do completely
The reason why they appear normal is because this condition is not fatal on its own, but people born without the celebration experience severe developmental delays, language deficits, neurological abnormalities. But the goodnews is as children with cerebellar agenesis get older, their movements usually improve.
This condition is real and was first reported in 1831. 10 cases has been reported as of 1998. The agenesis of one half or another part of the cerebellum is more common than complete agenesis.