- Hypertonia (HP:0001276): A condition in which there is increased muscle tone so that arms or legs, for example, are stiff and difficult to move. Evidence: IEA. (OMIM:264070)
- Transient hyperphenylalaninemia (HP:0008297): A condition of not having consistently high levels of phenylalanine in the blood but of experiencing temporary hyperphenylalaninemia following ingestion of large quantities of phenylalanine (for instance, following an oral loading test with phenylalanine). Evidence: PCS. (PMID:9585615)
- Elevated urinary 7-biopterin level (HP:0033594): An abnormally increased amount of 7-biopterin in the urine. Evidence: PCS. Frequency: 13/13. (PMID:9585615)
- Generalized hypotonia (HP:0001290): Generalized muscular hypotonia (abnormally low muscle tone). Evidence: PCS. Frequency: 2/13. (PMID:9585615)
- 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:9585615)
- Motor delay (HP:0001270): A type of Developmental delay characterized by a delay in acquiring motor skills. Evidence: PCS. Frequency: 1/13. (PMID:9585615)
- Hyperphenylalaninemia (HP:0004923): The concentration of L-phenylalanine in the blood circulation is above the upper limit of normal. Evidence: PCS. (PMID:9585615)
- Tremor (HP:0001337): An unintentional, oscillating to-and-fro muscle movement about a joint axis. Evidence: IEA. (OMIM:264070)
These phenotypes are associated with the disease pterin-4 alpha-carbinolamine dehydratase 1 deficiency (OMIM:264070).