Cerebellar agenesis

{{Short description|Brain development disorder}}

Cerebellar agenesis is a rare condition in which a brain develops without the cerebellum. The cerebellum controls smooth movement, and when it does not develop, the rest of the brain must compensate, which it cannot do completely. The condition is not fatal on its own, but people born without a cerebellum experience severe developmental delays, language deficits, and neurological abnormalities.{{cite journal |vauthors=Bolduc ME, Limperopoulos C |title=Neurodevelopmental outcomes in children with cerebellar malformations: a systematic review |journal=Dev Med Child Neurol |volume=51 |issue=4 |pages=256–67 |date=April 2009 |pmid=19191827 |doi=10.1111/j.1469-8749.2008.03224.x |s2cid=41825836 |url=https://escholarship.mcgill.ca/concern/articles/ff365970w |doi-access=free }} As children with cerebellar agenesis get older, their movements usually improve.{{cite journal |vauthors=Titomanlio L, Romano A, Del Giudice E |title=Cerebellar agenesis |journal=Neurology |volume=64 |issue=6 |pages=E21 | date=March 2005 |pmid=15781801 |doi= 10.1212/wnl.64.6.e21|doi-access=free }} It can co-exist with other severe malformations of the central nervous system, like anencephaly, holoprosencephaly, and microencephaly.{{cite journal |vauthors=Velioglu SK, Kuzeyli K, Ozmenoglu M |title=Cerebellar agenesis: a case report with clinical and MR imaging findings and a review of the literature |journal=Eur. J. Neurol. |volume=5 |issue=5 |pages=503–506 |date=September 1998 |pmid=10210881 |doi= 10.1046/j.1468-1331.1998.550503.x|s2cid=7679629 }}

The condition was first reported in 1831. Ten cases had been reported as of 1998. Agenesis of one half or another part of the cerebellum is more common than complete agenesis.{{cite journal |vauthors=Schmahmann JD, Weilburg JB, Sherman JC |title=The neuropsychiatry of the cerebellum - insights from the clinic |journal=Cerebellum |volume=6 |issue=3 |pages=254–67 |year=2007 |pmid=17786822 |doi=10.1080/14734220701490995 |s2cid=14176315 }}

Cerebellar agenesis can be caused by mutations in the PTF1A gene.{{cite journal |vauthors=Millen KJ, Gleeson JG |title=Cerebellar development and disease |journal=Curr. Opin. Neurobiol. |volume=18 |issue=1 |pages=12–9 | date=February 2008 |pmid=18513948 |pmc=2474776 |doi=10.1016/j.conb.2008.05.010 }}