- 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: TAS. (OMIM:210210)
- Ketoacidosis (HP:0001993): Acidosis resulting from accumulation of ketone bodies. Evidence: IEA. (OMIM:210210)
- Alopecia (HP:0001596): A noncongenital process of hair loss, which may progress to partial or complete baldness. Evidence: IEA. (OMIM:210210)
- Organic aciduria (HP:0001992): Excretion of non-amino organic acids in urine. Evidence: IEA. (OMIM:210210)
- Decreased circulating carnitine concentration (HP:0003234): Concentration of carnitine in the blood circulation below the lower limit of normal. Evidence: PCS. Frequency: 3/5. (PMID:17968484)
- Seizure (HP:0001250): A seizure is an intermittent abnormality of nervous system physiology characterized by a transient occurrence of signs and/or symptoms due to abnormal excessive or synchronous neuronal activity in the brain. Evidence: PCS. Frequency: 1/5. (PMID:17968484)
- Propionyl-CoA carboxylase deficiency (HP:0003353): An abnormality of amino acid metabolism characterized by a decreased level of propionyl-CoA carboxylase. Evidence: IEA. (OMIM:210210)
- Seborrheic dermatitis (HP:0001051): Seborrheic dermatitis is a form of eczema which is closely related to dandruff. It causes dry or greasy peeling of the scalp, eyebrows, and face, and sometimes trunk. Evidence: IEA. (OMIM:210210)
- 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: IEA. (OMIM:210210)
- Infantile onset (HP:0003593): Onset of signs or symptoms of disease between 28 days to one year of life. Evidence: PCS. Frequency: 4/5. (PMID:17968484)
- Generalized hypotonia (HP:0001290): Generalized muscular hypotonia (abnormally low muscle tone). Evidence: TAS. (OMIM:210210)
- 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:210210)
- Failure to thrive (HP:0001508): Failure to thrive (FTT) refers to a child whose physical growth is substantially below the norm. Evidence: PCS. Frequency: 1/5. (PMID:17968484)
- Hypoglycemia (HP:0001943): A decreased concentration of glucose in the blood. Evidence: IEA. (OMIM:210210)
- Hyperammonemia (HP:0001987): An increased concentration of ammonia in the blood. Evidence: PCS. Frequency: 2/5. (PMID:17968484)
- Hyperglycinuria (HP:0003108): An increased concentration of glycine in the urine. Evidence: IEA. (OMIM:210210)
- Intellectual disability (HP:0001249): The term intellectual disability or intellectual developmental disorder is used to describe significantly sub-average intellectual and adaptive functioning based on clinical assessment and as measured by individually administered, appropriately normed, standardized and validated tests of intellectual functioning and adaptive behavior, with onset during the developmental period from infancy through adolescence. Evidence: PCS. Frequency: 1/5. (PMID:17968484)
- 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: TAS. (OMIM:210210)
- Hyperreflexia (HP:0001347): Hyperreflexia is the presence of hyperactive stretch reflexes of the muscles. Evidence: TAS. (OMIM:210210)
- Opisthotonus (HP:0002179): Opisthotonus is defined as a dramatic abnormal posture due to spastic contraction of the extensor muscles of the neck, trunk, and lower extremities that produces a severe backward arching from neck to heel. In most cases, the trunk is elevated off the ground by a few inches. It is usually sudden in onset and can be sustained or repetitive. It can be considered a variant of decerebrate posturing involving a hyperextension of the neck, back, and limbs. Evidence: TAS. (OMIM:210210)
- Skeletal muscle atrophy (HP:0003202): The presence of skeletal muscular atrophy (which is also known as amyotrophy). Evidence: IEA. (OMIM:210210)
- Juvenile onset (HP:0003621): Onset of signs or symptoms of disease between the age of 5 and 15 years. Evidence: PCS. Frequency: 1/5. (PMID:17968484)
- Vomiting (HP:0002013): Forceful ejection of the contents of the stomach through the mouth by means of a series of involuntary spasmic contractions. Evidence: TAS. (OMIM:210210)
- Feeding difficulties (HP:0011968): Impaired ability to eat related to problems gathering food and getting ready to suck, chew, or swallow it. Evidence: TAS. (OMIM:210210)
- 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: 20/20. (OMIM:210210)
- Cerebral palsy (HP:0100021): Cerebral palsy describes a group of permanent disorders of the development of movement and posture, causing activity limitation, that are attributed to nonprogressive disturbances that occurred in the developing fetal or infant brain. The motor disorders of cerebral palsy are often accompanied by disturbances of sensation, perception, cognition, communication, and behavior, by epilepsy, and by secondary musculoskeletal problems. Evidence: PCS. Frequency: 1/5. (PMID:17968484)
- Hyperleucinemia (HP:0010911): The concentration of leucine in the blood circulation is above the upper limit of normal. Evidence: PCS. Frequency: 2/5. (PMID:17968484)
- Acute hyperammonemia (HP:0008281): An increased concentration of ammonia in the blood with sudden onset. Evidence: TAS. (OMIM:210210)
- 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:11181649)
- 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: TAS. (OMIM:210210)
These phenotypes are associated with the disease 3-methylcrotonyl-CoA carboxylase 2 deficiency (OMIM:210210).