- Lethargy (HP:0001254): A state of fatigue, either physical or mental slowness and sluggishness, with difficulties in initiating or performing simple tasks. Distinguished from apathy which implies indifference and a lack of desire or interest in the task. A person with lethargy may have the desire, but not the energy to engage in personal or socially relevant tasks. Evidence: PCS. Frequency: 1/1. Onset: Neonatal onset (HP:0003623). (PMID:29122468)
- Hypothermia (HP:0002045): Reduced body temperature due to failed thermoregulation. Evidence: PCS. Frequency: 1/1. (PMID:29122468)
- Poor suck (HP:0002033): An inadequate sucking reflex, resulting in the difficult of newborns to be breast-fed. Evidence: IEA. (OMIM:615026)
- Hypotonia (HP:0001252): Hypotonia is an abnormally low muscle tone (the amount of tension or resistance to movement in a muscle). Even when relaxed, muscles have a continuous and passive partial contraction which provides some resistance to passive stretching. Hypotonia thus manifests as diminished resistance to passive stretching. Hypotonia is not the same as muscle weakness, although the two conditions can co-exist. Evidence: PCS. Frequency: 1/1. (PMID:29122468)
- Decreased circulating vitamin B2 concentration (HP:0100504): The concentration of vitamin B2 in the blood circulation is below the lower limit of normal. Evidence: PCS. Frequency: 1/1. Onset: Neonatal onset (HP:0003623). (PMID:29122468)
- Hypoglycemia (HP:0001943): A decreased concentration of glucose in the blood. Evidence: IEA. (OMIM:615026)
- Elevated circulating acylcarnitine concentration (HP:0045045): Concentration of acylcarnitine in the blood circulation above the upper limit of normal. Evidence: PCS. Frequency: 1/1. (PMID:29122468)
- Autosomal dominant inheritance (HP:0000006): 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 heterozygotes. In the context of medical genetics, an autosomal dominant disorder is caused when a single copy of the mutant allele is present. Males and females are affected equally, and can both transmit the disorder with a risk of 50% for each child of inheriting the mutant allele. Evidence: PCS. (PMID:29122468)
- Dicarboxylic aciduria (HP:0003215): An increased concentration of dicarboxylic acid in the urine. Evidence: PCS. Frequency: 1/1. (PMID:29122468)
- Metabolic acidosis (HP:0001942): Metabolic acidosis (MA) is characterized by a fall in blood pH due to a reduction of serum bicarbonate concentration. This can occur as a result of either the accumulation of acids (high anion gap MA) or the loss of bicarbonate from the gastrointestinal tract or the kidney (hyperchloremic MA). By definition, MA is not due to a respirary cause. Evidence: PCS. Frequency: 1/1. Onset: Neonatal onset (HP:0003623). (PMID:29122468)
- 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: 1/1. (PMID:29122468)
These phenotypes are associated with the disease ariboflavinosis (OMIM:615026).