Table 2.

Selected Clinical Manifestations of GNB1 Encephalopathy

ManifestationFrequency (%) 1
Developmental delay57/57 (100%)
Intellectual disability35/47 (74%)
Abnormal muscle tone41/52 (79%)
Abnormal brain MRI25/50 (50%)
Epilepsy27/51 (53%)
Movement
disorder 		Dystonia11/50 (22%)
Other movement disorders7/50 (14%)
Sensory
impairment 		Abnormal vision31/52 (60%)
Sensorineural hearing loss3/47 (6%)
Behavior issues15/36 (42%)
Growth delay (height & weight < −2 SD)10/49 (20%)
Gastrointestinal problems12/19 (63%)
Genitourinary anomalies in males6/17 males (35%)
Macrocephaly (OFC > +2 SD)9/40 (22%)
Microcephaly (OFC < −2 SD)3/40 (7%)
Cardiovascular defects2/18 (11%)
Cutaneous mastocytosis4/34 (12%)
Craniofacial
anomalies 		Cleft palate5/58 (9%)
Craniosynostosis3/13 (23%)

OFC = occipital frontal circumference

1.

Frequency = # of persons with the manifestation / # of persons examined for this specific manifestation

From: GNB1 Encephalopathy

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