- Hyporeflexia (HP:0001265): Reduction of neurologic reflexes such as the knee-jerk reaction. Evidence: PCS. Frequency: 1/2. (PMID:15138885)
- Agenesis of corpus callosum (HP:0001274): Absence of the corpus callosum as a result of the failure of the corpus callosum to develop, which can be the result of a failure in any one of the multiple steps of callosal development including cellular proliferation and migration, axonal growth or glial patterning at the midline. Evidence: PCS. Frequency: 1/2. (PMID:15138885)
- 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. (PMID:15138885)
- Generalized hypotonia (HP:0001290): Generalized muscular hypotonia (abnormally low muscle tone). Evidence: PCS. Frequency: 2/2. (PMID:15138885)
- 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:15138885)
- Hyperammonemia (HP:0001987): An increased concentration of ammonia in the blood. Evidence: PCS. (PMID:15138885)
- Lactic acidosis (HP:0003128): An abnormal buildup of lactic acid in the body, leading to acidification of the blood and other bodily fluids. Evidence: PCS. Frequency: 2/2. Onset: Neonatal onset (HP:0003623). (PMID:15138885)
These phenotypes are associated with the disease pyruvate dehydrogenase E1-beta deficiency (OMIM:614111).