- Congenital onset (HP:0003577): A phenotypic abnormality that is present at birth. Evidence: PCS. (PMID:28556411)
- Polyhydramnios (HP:0001561): The presence of excess amniotic fluid in the uterus during pregnancy. Evidence: PCS. Frequency: 1/5. (PMID:28556411)
- 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. Frequency: 1/5. (PMID:28556411)
- Holoprosencephaly (HP:0001360): Holoprosencephaly is a structural anomaly of the brain in which the developing forebrain fails to divide into two separate hemispheres and ventricles. Evidence: PCS. Frequency: 1/5. (PMID:28556411)
- Brain atrophy (HP:0012444): Partial or complete wasting (loss) of brain tissue that was once present. Evidence: PCS. (PMID:28556411)
- Cerebellar agenesis (HP:0012642): Cerebellar agenesis is defined by the near complete absence of cerebellar tissue with only remnants of the anterior vermis, flocculus, and/or middle cerebellar peduncles. Evidence: PCS. Frequency: 2/5. (PMID:28556411)
- Abnormal facial shape (HP:0001999): An abnormal morphology (form) of the face or its components. Evidence: PCS. (PMID:28556411)
- 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:28556411)
- Dandy-Walker malformation (HP:0001305): A congenital brain malformation typically characterized by incomplete formation of the cerebellar vermis, dilation of the fourth ventricle, and enlargement of the posterior fossa. In layman's terms, Dandy Walker malformation is a cyst in the cerebellum (typically symmetrical) that is involved with the fourth ventricle. This may interfere with the ability to drain cerebrospinal fluid from the brain, resulting in hydrocephalus. Dandy Walker cysts are formed during early embryonic development, while the brain forms. The cyst in the cerebellum typically has several blood vessels running through it connecting to the brain, thereby prohibiting surgical removal. Evidence: PCS. Frequency: 1/5. (PMID:28556411)
- 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: 4/5. (PMID:28556411)
- Ventriculomegaly (HP:0002119): An increase in size of the ventricular system of the brain. Evidence: PCS. Frequency: 1/5. (PMID:28556411)
- Redundant neck skin (HP:0005989): Excess skin around the neck, often lying in horizontal folds. Evidence: PCS. Frequency: 1/5. (PMID:28556411)
- Hydranencephaly (HP:0002324): A defect of development of the brain characterized by replacement of greater portions of the cerebral hemispheres and the corpus striatum by cerebrospinal fluid (CSF) and glial tissue. Evidence: PCS. Frequency: 1/5. (PMID:28556411)
These phenotypes are associated with the disease hydrocephalus, congenital, 3, with brain anomalies (OMIM:617967).