Back تضخم الدماغ Arabic Megalenzephalie German Megaloencefalia Spanish مگالنسفالی Persian Megaloencefalia Italian Megaloencefalia Portuguese
| Megalencephaly | |
|---|---|
| Other names | Macrencephaly |
 | |
| MRI images showing megalencephaly in four family members who all have unusually large skulls (the family is affected by an autosomal recessive syndrome caused by a KIF7 mutation that induces multiple epiphyseal dysplasia)[1] | |
| Specialty | Medical genetics, neurology, pediatrics  |
| Usual onset | Congenital |
| Duration | Long-term |
Megalencephaly (or macrencephaly; abbreviated MEG) is a growth development disorder in which the brain is abnormally large. It is characterized by a brain with an average weight that is 2.5 standard deviations above the mean of the general population.[2] Approximately 1 out of 50 children (2%) are said to have the characteristics of megalencephaly in the general population.[3]
A mutation in the PI3K-AKT pathway is believed to be the primary cause of brain proliferation and ultimately the root cause of megalencephaly. This mutation has produced a classification of brain overdevelopment that consists of two syndromes including megalencephaly-capillary malformation (MCAP) and megalencephaly-polydactyly-polymicrogyria-hydrocephalus (MPPH).[4] Megalencephaly is usually diagnosed at birth and is confirmed with an MRI.
There are several neuropsychiatric disorders linked with megalencephaly; however, studies have shown that autism is the most prevalent association with the malformation of MEG.[5] Although no treatment currently exists for megalencephaly, management methods are focused at reducing deficits linked with autism. Most recent research is targeted at creating inhibitors to reduce the mutational pathway that causes megalencephaly.[6]
- ^ Ali BR, Silhavy JL, Akawi NA, Gleeson JG, Al-Gazali L (2012). "A mutation in KIF7 is responsible for the autosomal recessive syndrome of macrocephaly, multiple epiphyseal dysplasia and distinctive facial appearance". Orphanet Journal of Rare Diseases. 7: 27. doi:10.1186/1750-1172-7-27. PMC 3492204. PMID 22587682.
- ^ Striano, P; Federico (October 2012). "Mutations in mTOR pathway linked to megalencephaly syndromes". Nature Reviews Neurology. 8. 8 (10): 542–4. doi:10.1038/nrneurol.2012.178. PMID 22907262. S2CID 33405738.
- ^ Sandler, A; Knudsen; Brown; Christian (August 1997). "Neurodevelopmental dysfunction among nonreferred children with idiopathic megalencephaly". Journal of Pediatrics. 131 (2): 320–4. doi:10.1016/S0022-3476(97)70176-8. PMID 9290626.
- ^ Mirzaa, G; Riviere, Dobybns (May 2013). "Megalencephaly syndromes and activating mutations in the PI3K-AKT pathway: MPPH and MCAP". American Journal of Medical Genetics Part C. 163 (2): 122–30. doi:10.1002/ajmg.c.31361. PMID 23592320. S2CID 35211056.
- ^ Ghaziuddin, M; Zaccagnini; Tsai; Elardo (August 1999). "Is Megalencephaly specific to autism?" (PDF). Journal of Intellectual Disability Research. 43 (4): 279–82. doi:10.1046/j.1365-2788.1999.00211.x. hdl:2027.42/72452. PMID 10466865.
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