Bilateral generalized polymicrogyria (BGP): a distinct syndrome of cortical malformation.
BACKGROUND
Syndromes of bilateral symmetric polymicrogyria include an autosomal recessive form of bilateral frontoparietal polymicrogyria (BFPP), in which the malformation is most severe rostrally. The authors describe a new syndrome they have termed "bilateral generalized polymicrogyria" (BGP), in which the malformation occurs in a generalized distribution but is often most severe in the perisylvian regions.


METHODS
Patients with bilateral polymicrogyria were identified from multiple medical centers worldwide. The diagnosis of BGP was based on findings from conventional spin echo MRI and, in one case, postmortem neuropathologic findings. Genetic analysis was performed for those patients from consanguineous pedigrees and those with multiple affected siblings to rule out linkage to the BFPP locus on chromosome 16q.


RESULTS
Twelve patients were identified with BGP. Clinical features included cognitive and motor delay as well as seizures. Some specific features characteristic of other known bilateral polymicrogyria syndromes, such as pseudobulbar palsy and dysconjugate gaze, were not commonly seen in these patients. Radiologically, polymicrogyria appeared widespread but was often most severe in the perisylvian regions. Pathologic examination in one case revealed a diffusely thin and excessively folded cerebral cortex lacking normal six-layered architecture. Seven patients subjected to genetic analysis did not demonstrate linkage to the BFPP locus.


CONCLUSIONS
BGP is a distinct syndrome of cortical malformation. Several features allow BGP to be distinguished from other disorders on the growing list of bilateral symmetric polymicrogyria syndromes.
Chang
B S
BS
Division of Neurogenetics, Department of Neurology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, USA. bchang@bidmc.harvard.edu
Piao
X
X
Giannini
C
C
Cascino
G D
GD
Scheffer
I
I
Woods
C G
CG
Topcu
M
M
Tezcan
K
K
Bodell
A
A
Leventer
R J
RJ
Barkovich
A J
AJ
Grant
P E
PE
Walsh
C A
CA
D000015:Abnormalities, Multiple / Q000235:genetics; D002540:Cerebral Cortex / Q000002:abnormalities*; D002552:Cerebral Ventricles / Q000002:abnormalities; D002648:Child; D002675:Child, Preschool; D002885:Chromosomes, Human, Pair 16 / Q000235:genetics; D003241:Consanguinity; D002658:Developmental Disabilities / Q000209:etiology* / Q000235:genetics; D004828:Epilepsies, Partial / Q000209:etiology / Q000235:genetics; D017809:Fatal Outcome; D005260:Female; D005808:Genes, Recessive; D018740:Genetic Heterogeneity; D006801:Humans; D007223:Infant; D008607:Intellectual Disability / Q000209:etiology* / Q000235:genetics; D008279:Magnetic Resonance Imaging; D008297:Male; D018895:Microsatellite Repeats; D009421:Nervous System Malformations / Q000145:classification / Q000175:diagnosis / Q000235:genetics; D009468:Neuromuscular Diseases / Q000235:genetics; D010641:Phenotype; D011782:Quadriplegia / Q000235:genetics; D013577:Syndrome