- Megaloblastic anemia (HP:0001889): Anemia characterized by the presence of erythroblasts that are larger than normal (megaloblasts). Evidence: TAS. Frequency: Very frequent (HP:0040281). (ORPHA:79284)
- Hyperhomocystinemia (HP:0002160): An increased concentration of homocystine in the blood. Evidence: TAS. Frequency: Very frequent (HP:0040281). (ORPHA:79284)
- 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: TAS. Frequency: Very frequent (HP:0040281). (ORPHA:79284)
- Decreased circulating methylcobalamin concentration (HP:0003223): The concentration of methylcobalamin in the blood circulation is below the lower limit of normal. Methylcobalamin is a form of vitamin B12. Evidence: TAS. Frequency: Very frequent (HP:0040281). (ORPHA:79284)
- Methylmalonic aciduria (HP:0012120): Increased concentration of methylmalonic acid in the urine. Evidence: TAS. Frequency: Very frequent (HP:0040281). (ORPHA:79284)
- Elevated circulating palmitoleylcarnitine concentration (HP:0031544): The concentration palmitoleylcarnitine (hexadecenoylcarnitine or C16:1) in the blood circulation is above the upper limit of normal. Evidence: TAS. Frequency: Very frequent (HP:0040281). (ORPHA:79284)
- Decreased circulating vitamin B12 concentration (HP:0100502): The concentration of vitamin B12 in the blood circulation is below the lower limit of normal. Evidence: TAS. Frequency: Very frequent (HP:0040281). (ORPHA:79284)
- 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: TAS. Frequency: Frequent (HP:0040282). (ORPHA:79284)
- 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: TAS. Frequency: Frequent (HP:0040282). (ORPHA:79284)
- 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: TAS. Frequency: Frequent (HP:0040282). (ORPHA:79284)
- 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. Frequency: Frequent (HP:0040282). (ORPHA:79284)
- Failure to thrive (HP:0001508): Failure to thrive (FTT) refers to a child whose physical growth is substantially below the norm. Evidence: TAS. Frequency: Frequent (HP:0040282). (ORPHA:79284)
- Growth delay (HP:0001510): A deficiency or slowing down of growth pre- and postnatally. Evidence: TAS. Frequency: Frequent (HP:0040282). (ORPHA:79284)
- Intrauterine growth retardation (HP:0001511): An abnormal restriction of fetal growth with fetal weight below the tenth percentile for gestational age. Evidence: TAS. Frequency: Frequent (HP:0040282). (ORPHA:79284)
- Abnormal heart morphology (HP:0001627): Any structural anomaly of the heart. Evidence: TAS. Frequency: Frequent (HP:0040282). (ORPHA:79284)
- Abnormal facial shape (HP:0001999): An abnormal morphology (form) of the face or its components. Evidence: TAS. Frequency: Frequent (HP:0040282). (ORPHA:79284)
- Recurrent infections (HP:0002719): Increased susceptibility to infections as manifested by repeated bouts of infection. Evidence: TAS. Frequency: Frequent (HP:0040282). (ORPHA:79284)
- Feeding difficulties (HP:0011968): Impaired ability to eat related to problems gathering food and getting ready to suck, chew, or swallow it. Evidence: TAS. Frequency: Frequent (HP:0040282). (ORPHA:79284)
- Neurodevelopmental delay (HP:0012758): Neurodevelopmental delay (NDD) refers to delays in the maturation of the brain and central nervous system; infants and young children with NDD may experience delays in the development of one or more skills including gross motor abilities, fine-motor coordination, language abilities and ability to solve increasingly complex problems. Evidence: TAS. Frequency: Frequent (HP:0040282). (ORPHA:79284)
- Unilateral renal agenesis (HP:0000122): A unilateral form of agenesis of the kidney. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:79284)
- Cleft palate (HP:0000175): Cleft palate is a developmental defect of the palate resulting from a failure of fusion of the palatine processes and manifesting as a separation of the roof of the mouth (soft and hard palate). Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:79284)
- Glossitis (HP:0000206): Inflammation of the tongue. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:79284)
- Skin rash (HP:0000988): A red eruption of the skin. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:79284)
- 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: TAS. Frequency: Occasional (HP:0040283). (ORPHA:79284)
- Reduced number of intrahepatic bile ducts (HP:0006571): The presence of reduced numbers of intrahepatic bile duct than normal. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:79284)
- Stomatitis (HP:0010280): Stomatitis is an inflammation of the mucous membranes of any of the structures in the mouth. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:79284)
- Intraventricular hemorrhage (HP:0030746): Bleeding into the ventricles of the brain. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:79284)
These phenotypes are associated with the disease Methylmalonic acidemia with homocystinuria type cblF (ORPHA:79284).
The following phenotypes are NOT associated with this disease:
- Hypomethioninemia (HP:0003658): A decreased concentration of methionine in the blood. Evidence: TAS. (ORPHA:79284)