- Reduced orotidine 5-prime phosphate decarboxylase level (HP:0003267): An abnormal decrease in orotidine 5'-phosphate decarboxylase level. Evidence: IEA. (OMIM:258900)
- 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: TAS. Frequency: Occasional (HP:0040283). (OMIM:258900)
- Hematuria (HP:0000790): The presence of blood in the urine. Hematuria may be gross hematuria (visible to the naked eye) or microscopic hematuria (detected by dipstick or microscopic examination of the urine). Evidence: TAS. (OMIM:258900)
- Abnormal T cell physiology (HP:0011840): A functional anomaly of T cells. Evidence: TAS. Frequency: Occasional (HP:0040283). (OMIM:258900)
- Anisocytosis (HP:0011273): Abnormally increased variability in the size of erythrocytes. Evidence: TAS. (OMIM:258900)
- 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: TAS. Frequency: Occasional (HP:0040283). (OMIM:258900)
- Failure to thrive (HP:0001508): Failure to thrive (FTT) refers to a child whose physical growth is substantially below the norm. Evidence: PCS. Frequency: Occasional (HP:0040283). (PMID:9042911)
- Hypochromia (HP:0032231): A qualitative impression that red blood cells have less color than normal when examined under a microscope, usually related to a reduced amount of hemoglobin in the red blood cells. Evidence: IEA. (OMIM:258900)
- 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:9042911)
- Folate-unresponsive megaloblastic anemia (HP:0004826): A type of megaloblastic anemia that does not improve upon administration of folate. Since vitamin B12 acts by promoting recycling of folate, administration of vitamin B12 also does not improve this type of anemia. Evidence: IEA. (OMIM:258900)
- Oroticaciduria (HP:0003218): An increased concentration of orotic acid in the urine. Evidence: PCS. (PMID:9042911)
- Orotic acid crystalluria (HP:0003526): Formation of crystals owing to an increased concentration of orotic acid in the urine. Evidence: TAS. (OMIM:258900)
- Pyrimidine-responsive megaloblastic anemia (HP:0003339): A type of megaloblastic anemia that improves upon administration of pyrimidine supplements such as uridylic acid and cytidylic acid. Evidence: TAS. (OMIM:258900)
- 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: TAS. Frequency: Occasional (HP:0040283). (OMIM:258900)
- Poikilocytosis (HP:0004447): The presence of abnormally shaped erythrocytes. Evidence: TAS. (OMIM:258900)
These phenotypes are associated with the disease orotic aciduria (OMIM:258900).