- 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: IEA. (OMIM:251110)
- Decreased methylmalonyl-CoA mutase activity (HP:0003210): An abnormality of Krebs cycle metabolism that is characterized by a decreased rate of methylmalonyl-CoA mutase activity. Evidence: PCS. Frequency: 3/3. (PMID:20556797)
- Abnormal vitamin B12 concentration (HP:0004341): The concentration of vitamin B12 (or one of its metabolites) in the blood circulation is outside the limits of normal. Evidence: PCS. Frequency: 0/1. (PMID:35712814)
- 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:35712814)
- Hepatomegaly (HP:0002240): Abnormally increased size of the liver. Evidence: IEA. (OMIM:251110)
- Infantile onset (HP:0003593): Onset of signs or symptoms of disease between 28 days to one year of life. Evidence: PCS. Frequency: 1/5. (PMID:12471062)
- Elevated circulating propionylcarnitine concentration (HP:0033443): The concentration of propionylcarnitine in the blood circulation is above the upper limit of normal. Evidence: PCS. Frequency: 1/1. (PMID:35712814)
- Ketonuria (HP:0002919): High levels of ketone bodies (acetoacetic acid, beta-hydroxybutyric acid, and acetone) in the urine. Ketone bodies are insignificant in the blood and urine of normal individuals in the postprandial or overnight-fasted state. Evidence: IEA. (OMIM:251110)
- Failure to thrive (HP:0001508): Failure to thrive (FTT) refers to a child whose physical growth is substantially below the norm. Evidence: IEA. (OMIM:251110)
- Anemia (HP:0001903): A reduction in erythrocytes volume or hemoglobin concentration. Evidence: TAS. (OMIM:251110)
- Childhood onset (HP:0011463): Onset of disease at the age of between 1 and 5 years. Evidence: PCS. Frequency: 1/5. (PMID:12471062)
- Dehydration (HP:0001944). Evidence: IEA. (OMIM:251110)
- Feeding difficulties in infancy (HP:0008872): Impaired feeding performance of an infant as manifested by difficulties such as weak and ineffective sucking, brief bursts of sucking, and falling asleep during sucking. There may be difficulties with chewing or maintaining attention. Evidence: IEA. (OMIM:251110)
- Hyperammonemia (HP:0001987): An increased concentration of ammonia in the blood. Evidence: PCS. Frequency: 1/1. (PMID:35712814)
- Hypoglycemia (HP:0001943): A decreased concentration of glucose in the blood. Evidence: PCS. Frequency: 1/1. (PMID:35712814)
- Ketosis (HP:0001946): Presence of elevated levels of ketone bodies in the body. Evidence: IEA. (OMIM:251110)
- Methylmalonic acidemia (HP:0002912): The concentration of methylmalonic acid in the blood circulation is above the upper limit of normal. Evidence: PCS. Frequency: 1/1. (PMID:35712814)
- 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: IEA. (OMIM:251110)
- Dilated cardiomyopathy (HP:0001644): Dilated cardiomyopathy (DCM) is defined by the presence of left ventricular dilatation and left ventricular systolic dysfunction in the absence of abnormal loading conditions (hypertension, valve disease) or coronary artery disease sufficient to cause global systolic impairment. Right ventricular dilation and dysfunction may be present but are not necessary for the diagnosis. Evidence: PCS. Frequency: 1/1. (PMID:35712814)
- Neonatal onset (HP:0003623): Onset of signs or symptoms of disease within the first 28 days of life. Evidence: PCS. Frequency: 14/16. (PMID:35712814;PMID:12471062;OMIM:251110)
- Decreased circulating adenosylcobalamin concentration (HP:0003145): The concentration of adenosylcobalam in the blood circulation is below the lower limit of normal. Adenosylcobalamin is one of the active forms of vitamin B12. Evidence: PCS. Frequency: 5/6. (PMID:12471062)
- Vomiting (HP:0002013): Forceful ejection of the contents of the stomach through the mouth by means of a series of involuntary spasmic contractions. Evidence: IEA. (OMIM:251110)
- Respiratory distress (HP:0002098): Respiratory distress is objectively observable as the physical or emotional consequences from the experience of dyspnea. The physical presentation of respiratory distress is generally referred to as labored breathing, while the sensation of respiratory distress is called shortness of breath or dyspnea. Evidence: IEA. (OMIM:251110)
- Hyperglycinemia (HP:0002154): An elevated concentration of glycine in the blood. Evidence: IEA. (OMIM:251110)
- 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: IEA. (OMIM:251110)
- Delayed gross motor development (HP:0002194): A type of motor delay characterized by a delay in acquiring the ability to control the large muscles of the body for walking, running, sitting, and crawling. Evidence: PCS. Frequency: 1/1. (PMID:35712814)
- Persistent head lag (HP:0032988): The Premie-Neuro and the Dubowitz Neurological Examination score head lag in the same manner. Scoring for both is as follows: 0 = head drops and stays back, 1 = tries to lift head but drops it back, 2 = able to lift head slightly, 3 = lifts head in line with body, and 4 = head in front of body. This term applies if head lag persists beyond an expected age at a level of 0 or 1. Persistent head lag beyond age 4 mo has been linked to poor outcomes. Evidence: PCS. Frequency: 1/1. (PMID:35712814)
- Elevated circulating methylmalonylcarnitine concentration (HP:0035024): Concentration of methylmalonylcarnitine in the blood circulation above the upper limit of normal. Evidence: PCS. Frequency: 1/1. (PMID:35712814)
- Methylmalonic aciduria (HP:0012120): Increased concentration of methylmalonic acid in the urine. Evidence: PCS. Frequency: 11/11. (PMID:35712814;OMIM:251110)
- 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:12471062)
- Thrombocytopenia (HP:0001873): A reduction in the number of circulating thrombocytes. Evidence: TAS. (OMIM:251110)
- Pancytopenia (HP:0001876): An abnormal reduction in numbers of all blood cell types (red blood cells, white blood cells, and platelets). Evidence: IEA. (OMIM:251110)
- Coma (HP:0001259): The complete absence of wakefulness and consciousness, which is evident through a lack of response to any form of external stimuli. Evidence: IEA. (OMIM:251110)
- Decreased total neutrophil count (HP:0001875): Abnormal decrease of absolute number of neutrophils in the blood, per microlitre, compared to a reference range for a given sex and age-group. Evidence: IEA. (OMIM:251110)
These phenotypes are associated with the disease methylmalonic aciduria, cblB type (OMIM:251110).