- Microcephaly (HP:0000252): Head circumference below 2 standard deviations below the mean for age and gender. Evidence: TAS. Frequency: Occasional (HP:0040283). (OMIM:611134)
- Cleft palate (HP:0000175): Cleft palate is a developmental defect of the palate resulting from a failure of fusion of the palatine processes and manifesting as a separation of the roof of the mouth (soft and hard palate). Evidence: TAS. Frequency: Occasional (HP:0040283). (OMIM:611134)
- Anencephaly (HP:0002323): Anencephaly is a developmental anomaly characterized by a fetus that has no calvarium, with a lack of most or all of the fetus' brain tissue. Anencephaly belongs to a collective group known as neural tube defects (NTD) and is a result of the neural tube failing to close in its rostral end during fetal development. Evidence: TAS. Frequency: Occasional (HP:0040283). (OMIM:611134)
- Hypoplasia of the corpus callosum (HP:0002079): Underdevelopment of the corpus callosum. Evidence: PCS. (PMID:17564974)
- Postaxial hand polydactyly (HP:0001162): Supernumerary digits located at the ulnar side of the hand (that is, on the side with the fifth finger). Evidence: TAS. (OMIM:611134)
- Encephalocele (HP:0002084): A neural tube defect characterized by sac-like protrusions of the brain and the membranes that cover it through openings in the skull. Evidence: TAS. (OMIM:611134)
- Ventricular septal defect (HP:0001629): A hole between the two bottom chambers (ventricles) of the heart. The defect is centered around the most superior aspect of the ventricular septum. Evidence: PCS. (PMID:17564974)
- Bile duct proliferation (HP:0001408): Proliferative changes of the bile ducts. Evidence: TAS. (OMIM:611134)
- Renal cyst (HP:0000107): A fluid filled sac in the kidney. Evidence: TAS. (OMIM:611134)
- 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:17564974)
- 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. (PMID:17564974)
- Microphthalmia (HP:0000568): A developmental anomaly characterized by abnormal smallness of one or both eyes. Evidence: TAS. Frequency: Occasional (HP:0040283). (OMIM:611134)
- 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: TAS. Frequency: Occasional (HP:0040283). (OMIM:611134)
- Molar tooth sign on MRI (HP:0002419): An abnormal appearance of the midbrain in axial magnetic resonance imaging in which the elongated superior cerebellar peduncles give the midbrain an appearance reminiscent of a molar or wisdom tooth. Evidence: TAS. Frequency: Occasional (HP:0040283). (OMIM:611134)
- Bowing of the long bones (HP:0006487): A bending or abnormal curvature of a long bone. Evidence: TAS. Frequency: Occasional (HP:0040283). (OMIM:611134)
- Intrauterine growth retardation (HP:0001511): An abnormal restriction of fetal growth with fetal weight below the tenth percentile for gestational age. Evidence: TAS. (OMIM:611134)
- Atrial septal defect (HP:0001631): Atrial septal defect (ASD) is a congenital abnormality of the interatrial septum that enables blood flow between the left and right atria via the interatrial septum. Evidence: PCS. (PMID:17564974)
- Agenesis of cerebellar vermis (HP:0002335): Congenital absence of the vermis of cerebellum. Evidence: PCS. (PMID:17564974)
- Meningocele (HP:0002435): Protrusion of the meninges through a defect of the skull or vertebral column. Evidence: IEA. (OMIM:611134)
These phenotypes are associated with the disease Meckel syndrome, type 4 (OMIM:611134).