Polymicrogyria: Difference between revisions
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{{Image|Brain-disease-gyrification.png|right|400px|Gyrification from a clinical perspective: Normal adult human [[cerebral cortex|cortical surface]] (left), polymicrogyria (center) and [[lissencephaly]] (right).}} | |||
'''Polymicrogyria''' (abbrev. PMG, also known as ''cobblestone lissencephaly'' or ''microgyria'') is a [[neurodevelopmental disorder]] with abnormal [[gyrification]] of the [[cerebral cortex]]. Instead of the few and large convolutions ([[gyrus|gyri]]) typical for normal [[brain development]], multiple small convolutions occur, as a result of which the [[cortical surface]] appears [[pebble]]d. Histologically, polymicrogyria is characterized by a strong reduction (or even the complete lack) of layer V of the cerebral cortex. Further diagnostic criteria include [[white matter]] reduction, [[brain ventricle|ventricular]] enlargement, and [[hypoplasia]] of the [[brainstem]] and [[cerebellum]] ([[CZ:Ref:Pabuşçu 2002 Walker–Warburg syndrome variant|Pabuşçu et al., 2002]]; [[CZ:Ref:Jansen 2005 Genetics of the polymicrogyria syndromes|Jansen and Andermann, 2005]]). At least two genes have been found to be associated with polymicrogyria — [[GPR56 (gene)|GPR56]] ([[CZ:Ref:Piao 2004 G Protein-Coupled Receptor-Dependent Development of Human Frontal Cortex|Piao et al., 2004]]) and [[AHI1 (gene)|AHI1 gene]], though in the latter case, polymicrogyria is only one aspect of a wider disorder, [[Joubert syndrome]] ([[CZ:Ref:Dixon-Salazar 2004 Mutations in the AHI1 Gene, Encoding Jouberin, Cause Joubert Syndrome with Cortical Polymicrogyria|Dixon-Salazar et al., 2004]]). Polymicrogyria is also frequently associated with [[velocardiofacial syndrome|deletion 22q11.2 syndrome]] ([[CZ:Ref:Robin 2006 Polymicrogyria and deletion 22q11.2 syndrome: window to the etiology of a common cortical malformation|Robin et al., 2006]]), possibly due to [[perinatal]] [[cardiovascular]] effects ([[CZ:Ref:Barkovich 1995 Correlation of prenatal events with the development of polymicrogyria|Barkovich et al., 1995]]). | |||
Latest revision as of 08:31, 1 March 2024
This article uses direct referencing.
Gyrification from a clinical perspective: Normal adult human cortical surface (left), polymicrogyria (center) and lissencephaly (right).
Polymicrogyria (abbrev. PMG, also known as cobblestone lissencephaly or microgyria) is a neurodevelopmental disorder with abnormal gyrification of the cerebral cortex. Instead of the few and large convolutions (gyri) typical for normal brain development, multiple small convolutions occur, as a result of which the cortical surface appears pebbled. Histologically, polymicrogyria is characterized by a strong reduction (or even the complete lack) of layer V of the cerebral cortex. Further diagnostic criteria include white matter reduction, ventricular enlargement, and hypoplasia of the brainstem and cerebellum (Pabuşçu et al., 2002; Jansen and Andermann, 2005). At least two genes have been found to be associated with polymicrogyria — GPR56 (Piao et al., 2004) and AHI1 gene, though in the latter case, polymicrogyria is only one aspect of a wider disorder, Joubert syndrome (Dixon-Salazar et al., 2004). Polymicrogyria is also frequently associated with deletion 22q11.2 syndrome (Robin et al., 2006), possibly due to perinatal cardiovascular effects (Barkovich et al., 1995).