- Dysplastic corpus callosum (HP:0006989): Dysplasia and dysgenesis of the corpus callosum are nonspecific descriptions that imply defective development of the corpus callosum. The term dysplasia is applied when the morphology of the corpus callosum is altered as a congenital trait. For instance, the corpus callosum may be hump-shaped, kinked, or a striped corpus callosum that lacks an anatomically distinct genu and splenium. Evidence: PCS. (PMID:22578326)
- Mild intellectual disability (HP:0001256): Mild intellectual disability (ID) is defined as a type of ID characterized by mildly sub-average adaptive functioning and intellectual functioning, with an intelligence quotient (IQ) the range of 50-69. Evidence: PCS. Frequency: 5/12. (PMID:22578326)
- Cerebellar hypoplasia (HP:0001321): Cerebellar hypoplasia is a descriptive term implying a cerebellum with a reduced volume, but a normal shape and is stable over time. Evidence: PCS. (PMID:22578326)
- Hypoplasia of the corpus callosum (HP:0002079): Underdevelopment of the corpus callosum. Evidence: TAS. (PMID:22578326)
- Seizure (HP:0001250): A seizure is an intermittent abnormality of nervous system physiology characterized by a transient occurrence of signs and/or symptoms due to abnormal excessive or synchronous neuronal activity in the brain. Evidence: PCS. Frequency: 2/12. (PMID:22578326)
- Gray matter heterotopia (HP:0002282): Heterotopia or neuronal heterotopia are macroscopic clusters of misplaced neurons (gray matter), most often situated along the ventricular walls or within the subcortical white matter. Evidence: PCS. Frequency: 9/9. (PMID:22578326)
- Motor delay (HP:0001270): A type of Developmental delay characterized by a delay in acquiring motor skills. Evidence: PCS. Frequency: 5/12. (PMID:22578326)
- Cerebellar dysplasia (HP:0007033): Cerebellar dysplasia (abnormal growth or development) is defined by abnormal cerebellar foliation, white matter arborization, and gray-white matter junction. Cerebellar dysplasia is a neuroimaging finding that describes abnormalities of both the cerebellar cortex and white matter and is associated with variable neurodevelopmental outcome. Dysplasia may globally involve the cerebellum or affect only one cerebellar hemisphere. In addition, cerebellar dysplasia may be associated with cortical/subcortical cysts. Evidence: PCS. Frequency: 8/9. (PMID:22578326)
- Arachnoid cyst (HP:0100702): An extra-parenchymal and intra-arachnoidal collection of fluid with a composition similar to that of cerebrospinal fluid. Evidence: PCS. Frequency: 8/9. (PMID:22578326)
- Autosomal recessive inheritance (HP:0000007): A mode of inheritance that is observed for traits related to a gene encoded on one of the autosomes (i.e., the human chromosomes 1-22) in which a trait manifests in individuals with two pathogenic alleles, either homozygotes (two copies of the same mutant allele) or compound heterozygotes (whereby each copy of a gene has a distinct mutant allele). Evidence: PCS. (PMID:22578326)
- Hydrocephalus (HP:0000238): Hydrocephalus is an active distension of the ventricular system of the brain resulting from inadequate passage of CSF from its point of production within the cerebral ventricles to its point of absorption into the systemic circulation. Evidence: PCS. Frequency: 7/12. (PMID:22578326)
- Partial agenesis of the corpus callosum (HP:0001338): A partial failure of the development of the corpus callosum. Evidence: PCS. Frequency: 12/12. (PMID:22578326)
- Ventriculomegaly (HP:0002119): An increase in size of the ventricular system of the brain. Evidence: PCS. Frequency: 12/12. (PMID:22578326)
- Large foramen magnum (HP:0002700): An abnormal increase in the size of the foramen magnum. Evidence: PCS. (PMID:22578326)
- Polymicrogyria (HP:0002126): Polymicrogyria is a congenital malformation of the cerebral cortex characterized by abnormal cortical layering (lamination) and an excessive number of small gyri (folds). Evidence: PCS. Frequency: 9/9. (PMID:22578326)
- Severe sensorineural hearing impairment (HP:0008625): A severe form of sensorineural hearing impairment. Evidence: PCS. Frequency: 12/12. Onset: Childhood onset (HP:0011463). (PMID:22578326)
These phenotypes are associated with the disease Chudley-McCullough syndrome (OMIM:604213).