- Cerebellar vermis hypoplasia (HP:0001320): Underdevelopment of the vermis of cerebellum. Evidence: PCS. Frequency: 1/3. (PMID:23246003)
- Congenital onset (HP:0003577): A phenotypic abnormality that is present at birth. Evidence: PCS. Frequency: 3/3. (PMID:23246003)
- Delayed speech and language development (HP:0000750): A degree of language development that is significantly below the norm for a child of a specified age. Evidence: PCS. Frequency: 3/3. (PMID:23246003)
- Hypoplasia of the brainstem (HP:0002365): Underdevelopment of the brainstem. Evidence: PCS. Frequency: 2/3. (PMID:23246003)
- Subcortical band heterotopia (HP:0032409): A form of subcortical heterotopia with mislocalized gray matter within the white matter.It is defined as longitudinal bands of gray matter located deep to the cerebral cortex and separated from it by a thin layer of normal appearing white matter. It is part of the lissencephaly spectrum. Evidence: PCS. Frequency: 1/3. (PMID:23246003)
- Dilated fourth ventricle (HP:0002198): An abnormal dilatation of the fourth cerebral ventricle. Evidence: PCS. Frequency: 1/3. (PMID:23246003)
- Global developmental delay (HP:0001263): A delay in the achievement of motor or mental milestones in the domains of development of a child, including motor skills, speech and language, cognitive skills, and social and emotional skills. This term should only be used to describe children younger than five years of age. Evidence: PCS. Frequency: 3/3. (PMID:23246003)
- Dysgenesis of the basal ganglia (HP:0025102): Structural abnormality of the basal ganglia related to defective development. Evidence: PCS. Frequency: 3/3. (PMID:23246003)
- Ataxia (HP:0001251): Ataxia refers to impaired coordination of voluntary muscle movement. Cerebellar ataxia refers to ataxia due to dysfunction of the cerebellum. This causes a variety of elementary neurological deficits including asynergy (lack of coordination between muscles, limbs and joints), dysmetria (lack of ability to judge distances that can lead to under- or overshoot in grasping movements), and dysdiadochokinesia (inability to perform rapid movements requiring antagonizing muscle groups to be switched on and off repeatedly). Evidence: PCS. Frequency: 1/3. (PMID:23246003)
- Thin corpus callosum (HP:0033725): An abnormally thin corpus callous, due to atrophy, hypoplasia or agenesis. This term is intended to be used in situations where it is not known if thinning of the corpus callosum (for instance, as visualized by magnetic resonance tomography) is due to abnormal development (e.g. a leukodystrophy) or atrophy following normal development (e.g. neurodegeneration). Evidence: PCS. Frequency: 1/3. (PMID:23246003)
- Focal polymicrogyria (HP:0032471): Polymicrogyria affecting one or multiple small areas of the cerebral cortex. Evidence: PCS. Frequency: 1/3. (PMID:23246003)
- Primary microcephaly (HP:0011451): Head circumference below 2 standard deviations below the mean for age and gender at birth. Evidence: PCS. Frequency: 3/3. (PMID:23246003)
- Cortical dysplasia (HP:0002539): The presence of developmental dysplasia of the cerebral cortex. Evidence: PCS. Frequency: 1/3. (PMID:23246003)
- Microphthalmia (HP:0000568): A developmental anomaly characterized by abnormal smallness of one or both eyes. Evidence: PCS. Frequency: 1/3. (PMID:23246003)
- Partial agenesis of the corpus callosum (HP:0001338): A partial failure of the development of the corpus callosum. Evidence: PCS. Frequency: 2/3. (PMID:23246003)
- Retinal dysplasia (HP:0007973): Abnormal growth and differentiation, structure and appearance of the retina present from birth. Evidence: PCS. Frequency: 1/3. (PMID:23246003)
- Autosomal dominant inheritance (HP:0000006): 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 heterozygotes. In the context of medical genetics, an autosomal dominant disorder is caused when a single copy of the mutant allele is present. Males and females are affected equally, and can both transmit the disorder with a risk of 50% for each child of inheriting the mutant allele. Evidence: PCS. (PMID:23246003)
These phenotypes are associated with the disease complex cortical dysplasia with other brain malformations 6 (OMIM:615771).