• We are sorry, but NCBI web applications do not support your browser and may not function properly. More information

NCBI Bookshelf. A service of the National Library of Medicine, National Institutes of Health.

Pagon RA, Adam MP, Ardinger HH, et al., editors. GeneReviews® [Internet]. Seattle (WA): University of Washington, Seattle; 1993-2014.

Cover of GeneReviews®

GeneReviews® [Internet].

Show details

Polymicrogyria Overview

, MD, , MD, PhD, , ScM, and , MS, CGC.

Author Information
, MD
Neurogenetics
Beth Israel Deaconess Medical Center
Harvard Medical School
Boston, Massachusetts
, MD, PhD
Neurogenetics
Beth Israel Deaconess Medical Center
Harvard Medical School
Boston, Massachusetts
, ScM
Beth Israel Deaconess Medical Center
Harvard Medical School
Boston, Massachusetts
, MS, CGC
Neurogenetics
Beth Israel Deaconess Medical Center
Harvard Medical School
Boston, Massachusetts

Initial Posting: ; Last Update: August 6, 2007.

Summary

Disease characteristics. Polymicrogyria is characterized by stable neurologic deficits, i.e., a "static encephalopathy." The mildest form, unilateral focal polymicrogyria, may have minimal neurologic manifestations. In more severe forms, focal, motor, sensory, visual, or cognitive problems may be present, depending on the brain region affected. In the most widespread form, bilateral generalized polymicrogyria, severe intellectual disability, cerebral palsy, and refractory epilepsy may be present.

Diagnosis/testing. The diagnosis is typically made by magnetic resonance imaging (MRI) that reveals either irregularity to the cortical surface suggestive of multiple small folds or an irregular, scalloped appearance of the gray matter-white matter junction. The cerebral cortex often appears abnormally thick. Polymicrogyria can result from both genetic and environmental causes and can occur as an isolated finding with no other systemic involvement or as part of a syndrome with multisystem involvement. To date the only gene known to be associated with polymicrogyria is GPR56.

Genetic counseling. GPR56-related bilateral frontoparietal polymicrogyria has a confirmed genetic cause; it is inherited in an autosomal recessive manner. Bilateral frontal polymicrogyria and bilateral generalized polymicrogyria are also thought to be inherited in an autosomal recessive manner. Perisylvian polymicrogyria appears to be genetically heterogeneous with a number of families suggesting autosomal dominant, autosomal recessive, or X-linked inheritance. It may not be possible to determine the underlying cause or inheritance pattern of perisylvian polymicrogyria in those families in which only one child is affected. Prenatal diagnosis for GPR56-related bilateral frontoparietal polymicrogyria is possible for pregnancies at risk if the disease-causing mutations have been identified in an affected family member.

Management. Treatment of manifestations: Physical therapy, pharmacologic management, orthotic devices, and surgery for those with spastic motor impairment; speech therapy for language impairment; occupational therapy for fine motor difficulties; antiepileptic drugs for seizures; assessment of educational needs and evaluations for speech, vision, and hearing difficulties in infancy and preschool years.

Prevention of secondary complications: For individuals with cerebral palsy, measures to help prevent joint contractures and decubitus ulcers.

Definition

Clinical Manifestations of Polymicrogyria

The clinical manifestations of polymicrogyria are stable neurologic deficits, i.e., a "static encephalopathy."

  • In the mildest form, polymicrogyria is unilateral with only one small region of the brain involved; d neurologic problems may not be evident.
  • In more severe forms, focal motor, sensory, visual, or cognitive problems may be present, depending on the location of the brain region affected.
  • In the most severe forms, polymicrogyria is bilateral and generalized, resulting in severe intellectual disability, cerebral palsy, and refractory epilepsy.

Regression of development or loss of previously acquired skills does not generally occur; however, some clinical manifestations (particularly seizures) that appear later in childhood may significantly affect the overall clinical course [Guerrini et al 2003].

Individuals with the milder forms of polymicrogyria survive into adulthood, while those with the most severe forms may die at a young age as a result of such complications as seizures or pneumonia.

Establishing the Diagnosis of Polymicrogyria

Polymicrogyria is an abnormality of the developing brain characterized by abnormal cortical lamination and an unusual folding pattern of the cerebral cortex such that all or part of the brain surface is taken up by an excessive number of small gyri (folds).

Neuroimaging. The diagnosis of polymicrogyria is typically made by magnetic resonance imaging (MRI) since computed tomography (CT) and other imaging methods generally do not have high enough resolution or adequate contrast to identify the small folds that define the condition. In particular, MRI can demonstrate an irregularity to the cortical surface suggestive of multiple small folds or an irregular, scalloped appearance to the gray matter-white matter junction; the latter is often more evident [Raybaud et al 1996]. The cerebral cortex often appears abnormally thick as well because the multiple small gyri are fused, infolded, and superimposed in appearance.

Polymicrogyria is usually isolated but can also be seen in association with other brain malformations. In certain malformations, such as schizencephaly, polymicrogyria is almost invariably present (in this case, along the cleft that connects the ventricle to the brain surface). The association of polymicrogyria with gray matter heterotopia, agenesis of the corpus callosum, and other developmental brain anomalies has been reported.

Neuropathology. Gross neuropathologic examination reveals a pattern of complex convolutions to the cerebral cortex, with miniature gyri fused and superimposed together, often resulting in an irregular brain surface. The cortical ribbon can appear excessively thick as a result of the infolding and fusion of multiple small gyri.

Microscopic examination demonstrates that the cerebral cortex is in fact abnormally thin and has abnormal lamination; typically the cortex is unlayered or has four layers, in contrast to the normal six layers. The most superficial layers between adjacent small gyri appear fused, with the pia (layer of the meninges) bridging across multiple gyri [Harding & Copp 1997].

Differential Diagnosis of Polymicrogyria

Polymicrogyria needs to be distinguished from "pachygyria," a distinct brain malformation in which the surface folds are excessively broad and sparse. Pachygyria and polymicrogyria may look similar on low-resolution neuroimaging such as CT because the cortical thickness can appear to be increased and the gyri can appear to be broad and smooth in both conditions. The irregular, scalloped, or corrugated appearance of the gray-white junction that characterizes polymicrogyria and that is particularly evident on T1-weighted inversion recovery sequences usually distinguishes the two malformations [Raybaud et al 1996].

Lissencephaly ("smooth brain") is the extreme form of pachygyria. In lissencephaly, few or no sulci are seen on the cortical surface, resulting in a broad, smooth appearance to the entire brain. Lissencephaly can be radiologically confused with polymicrogyria, particularly with low-resolution imaging, but the smoothness and lack of irregularity in the gray-white junction, along with markedly increased cortical thickness, distinguishes lissencephaly.

Another set of disorders, collectively termed the "cobblestone lissencephalies," includes brain malformations associated with congenital muscular dystrophy. The cobblestone lissencephalies comprise Fukuyama congenital muscular dystrophy, Walker-Warburg syndrome, and muscle-eye-brain disease. In cobblestone lissencephaly, the brain surface actually has a bumpy contour caused by the presence of collections of misplaced neurons and glial cells that have migrated beyond the normal surface boundaries of the brain. Sometimes regions populated by these misplaced cells have caused a radiologic misdiagnosis of polymicrogyria. However, the presence of other abnormalities in these cobblestone lissencephaly syndromes, including ocular anomalies, congenital muscular dystrophy, ventriculomegaly, and cerebellar dysplasia, usually distinguishes these disorders from polymicrogyria.

Prevalence of Polymicrogyria

Although polymicrogyria in all its forms collectively is a fairly common brain malformation, each individual disorder in which it can be observed is rare. Perisylvian polymicrogyria is the most commonly described syndrome; its prevalence, like that of the other syndromes with polymicrogyria, remains unknown.

The majority of families with bilateral frontoparietal polymicrogyria (BFPP) studied to identify the gene in which mutation is causative (GPR56) were consanguineous families from the Middle East, although mutations have been identified in families from other ethnic groups as well.

Causes

Polymicrogyria can result from both genetic and environmental etiologies. It can occur as an isolated finding with no other systemic involvement or as part of a syndrome with multisystem involvement.

Environmental Causes

The environmental insults associated with the subsequent development of polymicrogyria include intrauterine infection (e.g., cytomegalovirus [CMV], toxoplasmosis, syphilis, and varicella-zoster [VZV]) and intrauterine ischemia (as in twin-twin transfusion).

Heritable Causes

Chromosomal/contiguous-gene disorders. Deletion 22q11.2 has been associated with polymicrogyria and other developmental abnormalities [Sztriha et al 2004, Robin et al 2006].

Single gene disorders. Aicardi syndrome has been associated with polymicrogyria and other cerebral malformations including agenesis of the corpus callosum, subependymal heterotopia, and deficiency of the falx cerebri [Barkovich et al 2001]. A potential locus for this condition at Xp22 has not been confirmed.

Inborn errors of metabolism associated with polymicrogyria include glycine encephalopathy (nonketotic hyperglycinemia), pyruvate dehydrogenase deficiency, glutaric acidemia type II (see Organic Aciduria Overview), Zellweger syndrome, and neonatal adrenoleukodystrophy (see Peroxisomal Biogenesis Disorders, Zellweger Type) [Harding & Copp 1997].

Nonsyndromic Mendelian disorders with polymicrogyria involving only the brain are summarized in Table 1, Table 2, and Table 3.

Table 1. Nonsyndromic Mendelian Disorders with Polymicrogyria: Clinical Findings

SyndromeGenetic BasisClinical FeaturesReference
Bilateral frontal polymicrogyria (BFP)Presumed autosomal recessiveCognitive and motor delay, spastic quadriparesis, epilepsyGuerrini et al [2000]
Bilateral frontoparietal polymicrogyria (BFPP)Autosomal recessiveSevere cognitive and motor delay, seizures, dysconjugate gaze, cerebellar dysfunction[Piao et al 2002, Chang et al 2003, Piao et al 2005]
Bilateral perisylvian polymicrogyria (BPP)Autosomal dominant, autosomal recessive, X-linkedPseudobulbar signs 1 , cognitive impairment, epilepsy, some with arthrogryposis and/or lower motor neuron disease[Gropman et al 1997, Guerreiro et al 2000, Villard et al 2002, Jansen et al 2005, Clark et al 2006]
Bilateral parasagittal parieto-occipital polymicrogyria (BPPP)All cases simplexPartial seizures, some with intellectual disability[Guerrini et al 1997]
Bilateral generalized polymicrogyria (BGP)Presumed autosomal recessiveCognitive and motor delay of variable severity, seizures[Chang et al 2004]

Adapted from Chang et al [2004], with permission from Lippincott Williams & Wilkins

1. Range from severe (inability to feed in infancy) to mild (minor speech impediment), sometimes called "faciopharyngoglosssomasticatory paresis"

Table 2. Nonsyndromic Mendelian Disorders with Polymicrogyria: Radiologic Findings

SyndromeAffected RegionsRadiologic Findings
Bilateral frontal polymicrogyria (BFP)Image polyFigA.jpgSymmetric PMG 1 extending from frontal poles posteriorly to precentral gyrus and inferiorly to frontal operculum
Bilateral frontoparietal polymicrogyria (BFPP)Image polyFigB.jpgSymmetric generalized PMG with decreasing anterior-posterior gradient, most prominent in frontoparietal cortex
Bilateral perisylvian polymicrogyria (BPP)Image polyFigC.jpgPMG in the perisylvian region, usually bilateral
Bilateral parasagittal parieto-occipital polymicrogyria (BPPP)Image polyFigD.jpgBilateral PMG in parasagittal and mesial aspects of parieto-occipital cortex
Bilateral generalized polymicrogyria (BGP)Image polyFigE.jpgSymmetric generalized PMG, often most prominent in perisylvian regions

Adapted from Chang et al [2004], with permission from Lippincott Williams & Wilkins

1. PMG = polymicrogyria

Table 3. Nonsyndromic Mendelian Disorders with Polymicrogyria: Molecular Genetics

Disease NameGene Symbol/
Protein Name
Chromosomal Locus 1 Reference
Bilateral perisylvian polymicrogyria (BPP)UnknownXq28Villard et al [2002]
Bilateral frontal polymicrogyria (BFP)UnknownUnknown
Bilateral generalized polymicrogyria (BGP)UnknownUnknown
Bilateral frontoparietal polymicrogyria (BFPP)GPR56/
G protein-coupled receptor 56
Piao et al [2004]

1. Chromosomal locus included if gene is unidentified

GPR56 consists of 14 exons covering 15 kb of genomic sequence. The protein encoded by GPR56, G-protein coupled receptor 56, is widely expressed throughout the body; it appears to be essential during human cerebral cortical development and patterning.

Among 29 persons with typical clinical and radiologic features of BFPP [Piao et al 2005], all were found to have one of 11 identified GPR56 mutations, including a number of distinct founder mutations from various populations throughout the world. In individuals with GPR56-associated BFPP, no phenotype has been observed outside the central nervous system. Because the central nervous system phenotype associated with these mutations was quite uniform, the mutations were felt to represent null alleles.

Persons with a distinct syndrome characterized by findings similar to BFPP in the cerebral cortex but without any white matter or posterior fossa abnormalities have not been found to harbor GPR56 mutations. Similarly, individuals with a variety of other polymicrogyria syndromes including bilateral frontal polymicrogyria, bilateral perisylvian polymicrogyria, and bilateral generalized polymicrogyria have not been found to have mutations in GPR56.

Unknown Causes

For the majority of individuals, an underlying cause for polymicrogyria cannot be identified, although exact figures are unknown.

Evaluation Strategy

Once the diagnosis of polymicrogyria has been established in an individual, the following approach can be used to determine if a specific cause or mode of inheritance can be identified for aid in discussions of prognosis and genetic counseling.

  • Known environmental causes of polymicrogyria need to be excluded to the extent possible. A detailed pregnancy history should be sought, with particular regard to infections, trauma, multiple gestations, and other documented problems. Screening for the common congenital infections associated with polymicrogyria with standard TORCH testing may be appropriate. Other specific tests targeting individual neurometabolic disorders can be obtained if clinically suggested.
  • If common environmental causes have been ruled out or appear unlikely, then a genetic cause of polymicrogyria should be considered. The following may help in determining a genetic etiology:
    • Family history. It is important to ask for the presence of neurologic problems in family members, including seizures, cognitive delay, motor impairment, pseudobulbar signs, and focal weakness because many affected family members, particularly those who are older, may not have had MRI performed, even if these problems came to medical attention. In addition, although most individuals with polymicrogyria do present with neurologic difficulties in infancy, childhood, or adulthood, those with mild forms may have no obvious deficit or only minor manifestations, such as a simple lisp or isolated learning disability. Therefore, if a familial polymicrogyria syndrome is suspected, it may be reasonable to perform MRI on relatives who are asymptomatic or have what appear to be minor findings. The presence of consanguinity in a child's parents may suggest an autosomal recessive familial polymicrogyria syndrome.
    • Physical examination. A general physical examination of the proband may identify associated craniofacial, musculoskeletal, or visceral malformations that could indicate a particular syndrome. Neurologic examination should assess cognitive and mental abilities, cranial nerve function, motor function, deep tendon reflexes, sensory function, coordination, and gait (if appropriate).
    • Genetic testing
      • FISH testing for 22q11.2 deletion is appropriate for those with clinical features suggesting this diagnosis, such as cleft palate or velopharyngeal insufficiency (VPI); congenital heart defects, especially conotruncal malformations; and distinctive facial features.
      • Subtelomeric FISH testing may also be appropriate in selected cases to identify submicroscopic chromosome rearrangements in subtelomeric regions [Zollino et al 2003].
      • Molecular genetic testing of 18 pedigrees with classic BFPP (with typical associated white matter and posterior fossa MRI features) identified GPR56 mutations in all 18. Mutations have not been identified in any individuals with cortical features of BFPP but lacking the other radiologic findings.

Genetic Counseling

Genetic counseling is the process of providing individuals and families with information on the nature, inheritance, and implications of genetic disorders to help them make informed medical and personal decisions. The following section deals with genetic risk assessment and the use of family history and genetic testing to clarify genetic status for family members. This section is not meant to address all personal, cultural, or ethical issues that individuals may face or to substitute for consultation with a genetics professional. —ED.

Mode of Inheritance

The cause of most polymicrogyria is not known.

Of the inherited disorders causing isolated polymicrogyria, only GPR56-related bilateral frontoparietal polymicrogyria (BFPP) has a confirmed genetic cause; BFPP is inherited in an autosomal recessive manner.

Bilateral frontal polymicrogyria and bilateral generalized polymicrogyria are thought to be inherited in an autosomal recessive manner, based on review of available pedigrees.

Perisylvian polymicrogyria appears to be genetically heterogeneous, with a number of families suggesting autosomal dominant, autosomal recessive, or X-linked inheritance. It may not be possible to determine the underlying cause or inheritance pattern of perisylvian polymicrogyria in those families in which only one child is affected.

Risk to Family Members — GPR56-Related BFPP, Autosomal Recessive

Parents of a proband

  • The parents of an affected individual are obligate heterozygotes and therefore carry one mutant allele.
  • Heterozygotes (carriers) are asymptomatic.

Sibs of a proband

  • At conception, each sib of an affected individual has a 25% chance of being affected, a 50% chance of being an asymptomatic carrier, and a 25% chance of being unaffected and not a carrier.
  • Once an at-risk sib is known to be unaffected, the risk of his/her being a carrier is 2/3.
  • Heterozygotes (carriers) are asymptomatic.

Offspring of a proband

  • Offspring of a proband are obligate heterozygotes and will therefore carry one mutant allele.
  • In populations with a high rate of consanguinity, the offspring of a person with GPR56-related BFPP and a reproductive partner who is a carrier of GPR56-related BFPP have a 50% chance of inheriting two GPR56 disease-causing alleles and having BFPP and a 50% chance of being carriers.

Other family members of a proband. Each sib of the proband's parents is at a 50% risk of being a carrier.

Carrier Detection

Carrier testing for GPR56-related BFPP using molecular genetic techniques is possible if the disease-causing mutations have been identified in the family.

Related Genetic Counseling Issues

Risk to family members of individuals with polymicrogyria not caused by GPR56 mutations. For families in which the mode of inheritance is clearly demonstrated by family history or by the identification of a GPR56 mutation in a clinical laboratory, risks to family members can be determined according to standard genetic principles. For families of individuals who are the only known affected family member (i.e., simplex cases) and in whom a GPR56 mutation has not been identified, mode of inheritance is unknown and, thus, risks to family members are uncertain.

Family planning. The optimal time for determination of genetic risk is before pregnancy. It is appropriate to offer genetic counseling (including discussion of potential risks to offspring and reproductive options) to young adults who are affected or at risk of being carriers.

DNA banking is the storage of DNA (typically extracted from white blood cells) for possible future use. Because it is likely that testing methodology and our understanding of genes, mutations, and diseases will improve in the future, consideration should be given to banking DNA of affected individuals.

Prenatal Testing

If the disease-causing mutations have been identified in the family, prenatal diagnosis for pregnancies at increased risk is possible by analysis of DNA extracted from fetal cells obtained by amniocentesis (usually performed at ~15-18 weeks’ gestation) or chorionic villus sampling (usually performed at ~10-12 weeks’ gestation).

Note: Gestational age is expressed as menstrual weeks calculated either from the first day of the last normal menstrual period or by ultrasound measurements.

Preimplantation genetic diagnosis may be available for families in which the disease-causing mutations have been identified.

Resources

GeneReviews staff has selected the following disease-specific and/or umbrella support organizations and/or registries for the benefit of individuals with this disorder and their families. GeneReviews is not responsible for the information provided by other organizations. For information on selection criteria, click here.

  • PMG Awareness Organization, Inc.
    P.O. Box 47603
    Jacksonville FL 32247
    Phone: 904-894-9745
    Email: information@pmgawareness.org

Management

Evaluations Following Initial Diagnosis

To establish the extent of disease in an individual diagnosed with polymicrogyria, the following evaluations are recommended:

  • Evaluations by physical therapists, occupational therapists, and other specialists in infancy and the preschool years because of the high risk of intellectual disability and cerebral palsy
  • Assessment of special educational needs
  • Speech evaluations for those with perisylvian polymicrogyria
  • Vision and hearing evaluation as clinically appropriate
  • EEG in the presence of episodic clinical events of uncertain cause

Treatment of Manifestations

The following treatment is recommended:

  • Supportive management, including physical therapy, pharmacologic management, orthotic devices, and surgery for those with spastic motor impairment
  • Speech therapy for those with language impairment
  • Occupational therapy for those with language impairment
  • Antiepileptic drugs (AEDs) for seizures based on the specific epilepsy type

Prevention of Secondary Complications

The following are appropriate:

  • Education of parents about common seizure presentations
  • Supportive measures, particularly for individuals with cerebral palsy, which may help to prevent the development of secondary complications such as joint contractures and decubitus ulcers

Therapies Under Investigation

Search ClinicalTrials.gov for access to information on clinical studies for a wide range of diseases and conditions. Note: There may not be clinical trials for this disorder.

References

Literature Cited

  1. Barkovich AJ, Simon EM, Walsh CA. Callosal agenesis with cyst: a better understanding and new classification. Neurology. 2001;56:220–7. [PubMed: 11160959]
  2. Chang BS, Piao X, Bodell A, Basel-Vanagaite L, Straussberg R, Dobyns WB, Qasrawi B, Winter RM, Innes AM, Voit T, Grant PE, Barkovich AJ, Walsh CA. Bilateral frontoparietal polymicrogyria: clinical and radiological features in 10 families with linkage to chromosome 16. Ann Neurol. 2003;53:596–606. [PubMed: 12730993]
  3. Chang BS, Piao X, Giannini C, Cascino GD, Scheffer I, Woods CG, Topcu M, Tezcan K, Bodell A, Leventer RJ, Barkovich AJ, Grant PE, Walsh CA. Bilateral generalized polymicrogyria (BGP): a distinct syndrome of cortical malformation. Neurology. 2004;62:1722–8. [PubMed: 15159468]
  4. Clark M, Pitt M, Neville BG. Lower motor neuron involvement in perisylvian polymicrogyria. Dev Med Child Neurol. 2006;48:842–6. [PubMed: 16978465]
  5. Gropman AL, Barkovich AJ, Vezina LG, Conry JA, Dubovsky EC, Packer RJ. Pediatric congenital bilateral perisylvian syndrome: clinical and MRI features in 12 patients. Neuropediatrics. 1997;28:198–203. [PubMed: 9309709]
  6. Guerreiro MM, Andermann E, Guerrini R, Dobyns WB, Kuzniecky R, Silver K, Van Bogaert P, Gillain C, David P, Ambrosetto G, Rosati A, Bartolomei F, Parmeggiani A, Paetau R, Salonen O, Ignatius J, Borgatti R, Zucca C, Bastos AC, Palmini A, Fernandes W, Montenegro MA, Cendes F, Andermann F. Familial perisylvian polymicrogyria: a new familial syndrome of cortical maldevelopment. Ann Neurol. 2000;48:39–48. [PubMed: 10894214]
  7. Guerrini R, Barkovich AJ, Sztriha L, Dobyns WB. Bilateral frontal polymicrogyria: a newly recognized brain malformation syndrome. Neurology. 2000;54:909–13. [PubMed: 10690985]
  8. Guerrini R, Dubeau F, Dulac O, Barkovich AJ, Kuzniecky R, Fett C, Jones-Gotman M, Canapicchi R, Cross H, Fish D, Bonanni P, Jambaque I, Andermann F. Bilateral parasagittal parietooccipital polymicrogyria and epilepsy. Ann Neurol. 1997;41:65–73. [PubMed: 9005867]
  9. Guerrini R, Sicca F, Parmeggiani L. Epilepsy and malformations of the cerebral cortex. Epileptic Disord. 2003;5 Suppl 2:9–26. [PubMed: 14617417]
  10. Harding B, Copp AJ (1997) Malformations. In: Graham DI, Lantos PL, eds. Greenfield's Neuropathology. 6 ed. London, UK: Arnold; 1997.
  11. Jansen AC, Leonard G, Bastos AC, Esposito-Festen JE, Tampieri D, Watkins K, Andermann F, Andermann E. Cognitive functioning in bilateral perisylvian polymicrogyria (BPP): clinical and radiological correlations. Epilepsy Behav. 2005;6:393–404. [PubMed: 15820349]
  12. Piao X, Basel-Vanagaite L, Straussberg R, Grant PE, Pugh EW, Doheny K, Doan B, Hong SE, Shugart YY, Walsh CA. An autosomal recessive form of bilateral frontoparietal polymicrogyria maps to chromosome 16q12.2-21. Am J Hum Genet. 2002;70:1028–33. [PMC free article: PMC379097] [PubMed: 11845408]
  13. Piao X, Chang BS, Bodell A, Woods K, Benzeev B, Topcu M, Guerrini R, Goldberg-Stern H, Sztriha L, Dobyns WB, Barkovich AJ, Walsh CA. Genotype-phenotype analysis of human frontoparietal polymicrogyria syndromes. Ann Neurol. 2005;58:680–7. [PubMed: 16240336]
  14. Piao X, Hill RS, Bodell A, Chang BS, Basel-Vanagaite L, Straussberg R, Dobyns WB, Qasrawi B, Winter RM, Innes AM, Voit T, Ross ME, Michaud JL, Descarie JC, Barkovich AJ, Walsh CA. G protein-coupled receptor-dependent development of human frontal cortex. Science. 2004;303:2033–6. [PubMed: 15044805]
  15. Raybaud C, Girard N, Canto-Moreira N, Poncet M (1996) High-definition magnetic resonance imaging identification of cortical dysplasias: micropolygyria versus lissencephaly. In: Guerrini R, Andermann F, Canapicchi R, Roger J, Zifkin BG, Pfanner P (eds) Dysplasias of cerebral cortex and epilepsy. Lippincott-Raven, Philadelphia, pp 131-44.
  16. Robin NH, Taylor CJ, McDonald-McGinn DM, Zackai EH, Bingham P, Collins KJ, Earl D, Gill D, Granata T, Guerrini R, Katz N, Kimonis V, Lin JP, Lynch DR, Mohammed SN, Massey RF, McDonald M, Rogers RC, Splitt M, Stevens CA, Tischkowitz MD, Stoodley N, Leventer RJ, Pilz DT, Dobyns WB. Polymicrogyria and deletion 22q11.2 syndrome: window to the etiology of a common cortical malformation. Am J Med Genet A. 2006;140:2416–25. [PubMed: 17036343]
  17. Sztriha L, Guerrini R, Harding B, Stewart F, Chelloug N, Johansen JG. Clinical, MRI, and pathological features of polymicrogyria in chromosome 22q11 deletion syndrome. Am J Med Genet. 2004;127A:313–7. [PubMed: 15150787]
  18. Villard L, Nguyen K, Cardoso C, Martin CL, Weiss AM, Sifry-Platt M, Grix AW, Graham JM, Winter RM, Leventer RJ, Dobyns WB. A locus for bilateral perisylvian polymicrogyria maps to Xq28. Am J Hum Genet. 2002;70:1003–8. [PMC free article: PMC379093] [PubMed: 11822025]
  19. Zollino M, Colosimo C, Zuffardi O, Rossi E, Tosolini A, Walsh CA, Neri G. Cryptic t(1;12)(q44;p13.3) translocation in a previously described syndrome with polymicrogyria, segregating as an apparently X-linked trait. Am J Med Genet A. 2003;117:65–71. [PubMed: 12548742]

Chapter Notes

Suggested Reading

  1. Guerrini R, Marini C. Genetic malformations of cortical development. Exp Brain Res. 2006;173:322–33. [PubMed: 16724181]
  2. Jansen A, Andermann E. Genetics of the polymicrogyria syndromes. J Med Genet. 2005;42:369–78. [PMC free article: PMC1736054] [PubMed: 15863665]

Revision History

  • 6 August 2007 (me) Comprehensive update posted to live Web site
  • 18 April 2005 (me) Overview posted to live Web site
  • 24 August 2004 (bc) Original submission
Copyright © 1993-2014, University of Washington, Seattle. All rights reserved.

For more information, see the GeneReviews Copyright Notice and Usage Disclaimer.

For questions regarding permissions: ude.wu@tssamda.

Bookshelf ID: NBK1329PMID: 20301504
PubReader format: click here to try

Views

  • PubReader
  • Print View
  • Cite this Page
  • Disable Glossary Links

Tests in GTR by Gene

Related information

  • MedGen
    Related information in MedGen
  • PMC
    PubMed Central citations
  • PubMed
    Links to pubmed

Related citations in PubMed

See reviews...See all...

Recent Activity

Your browsing activity is empty.

Activity recording is turned off.

Turn recording back on

See more...