Phenotypes associated with the disease transcobalamin II deficiency (OMIM:275350):
- 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:275350)
- 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: 2/4. (PMID:7849710;PMID:19373259)
- 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: 0/2. (PMID:19373259)
- Infantile onset (HP:0003593): Onset of signs or symptoms of disease between 28 days to one year of life. Evidence: PCS. Frequency: 3/4. (PMID:7849710;PMID:19373259)
- Hepatomegaly (HP:0002240): Abnormally increased size of the liver. Evidence: PCS. Frequency: 1/1. (PMID:7849710)
- Ataxia (HP:0001251): Ataxia refers to impaired coordination of voluntary muscle movement. Cerebellar ataxia refers to ataxia due to dysfunction of the cerebellum. This causes a variety of elementary neurological deficits including asynergy (lack of coordination between muscles, limbs and joints), dysmetria (lack of ability to judge distances that can lead to under- or overshoot in grasping movements), and dysdiadochokinesia (inability to perform rapid movements requiring antagonizing muscle groups to be switched on and off repeatedly). Evidence: IEA. (OMIM:275350)
- Hyperhomocystinemia (HP:0002160): An increased concentration of homocystine in the blood. Evidence: PCS. Frequency: 1/3. (PMID:19373259)
- Erythroid hypoplasia (HP:0012133): Decreased count of erythroid precursor cells, that is, erythroid lineage cells in the bone marrow. Evidence: PCS. Frequency: 1/1. (PMID:7849710)
- Failure to thrive (HP:0001508): Failure to thrive (FTT) refers to a child whose physical growth is substantially below the norm. Evidence: PCS. Frequency: 4/4. (PMID:7849710;PMID:19373259)
- Irritability (HP:0000737): An emotional state characterized by negative feelings of heightened frustration, annoyance, or feeling upset, often triggered by internal factors (e.g., fatigue, hunger, unfulfilled desires) or external factors (e.g., social or environmental challenges). Irritability may be unpredictable, and is accompanied by a lowered threshold for emotional reactivity and observable features (speech, facial expressions, or psychomotor activity). Evidence: PCS. Frequency: 1/1. (PMID:7849710)
- Anemia (HP:0001903): A reduction in erythrocytes volume or hemoglobin concentration. Evidence: PCS. Frequency: 1/3. (PMID:19373259)
- Muscle weakness (HP:0001324): Reduced strength of muscles. Evidence: IEA. (OMIM:275350)
- 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: IEA. (OMIM:275350)
- Neonatal onset (HP:0003623): Onset of signs or symptoms of disease within the first 28 days of life. Evidence: PCS. Frequency: 1/3. (PMID:19373259)
- Decreased circulating IgG concentration (HP:0004315): An abnormally decreased level of immunoglobulin G (IgG) in blood. Evidence: IEA. (OMIM:275350)
- Megaloblastic bone marrow (HP:0001980): Abnormal increased number of megaloblasts in the bone marrow. Evidence: PCS. Frequency: 1/1. (PMID:7849710)
- Diarrhea (HP:0002014): Abnormally increased frequency (usually defined as three or more) loose or watery bowel movements a day. Evidence: IEA. Frequency: 1/3. (OMIM:275350)
- Decreased circulating IgM concentration (HP:0002850): An abnormally decreased level of immunoglobulin M (IgM) in blood. Evidence: IEA. (OMIM:275350)
- 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. Frequency: 2/3. (OMIM:275350)
- Abnormal circulating folate concentration (HP:0040087): Any deviation from the normal concentration of folate in the blood circulation. Evidence: PCS. Frequency: 0/1. (PMID:7849710)
- Methylmalonic aciduria (HP:0012120): Increased concentration of methylmalonic acid in the urine. Evidence: PCS. Frequency: 4/4. (PMID:7849710;PMID:19373259)
- 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:7849710)
- Reticulocytopenia (HP:0001896): A reduced number of reticulocytes in the peripheral blood. Evidence: IEA. (OMIM:275350)
- Macrocytic anemia (HP:0001972): A type of anemia characterized by increased size of erythrocytes with increased mean corpuscular volume (MCV) and increased mean corpuscular hemoglobin (MCH). Evidence: PCS. Frequency: 1/1. (PMID:7849710)
- Pancytopenia (HP:0001876): An abnormal reduction in numbers of all blood cell types (red blood cells, white blood cells, and platelets). Evidence: IEA. Frequency: 2/3. (OMIM:275350)
- Decreased circulating IgA concentration (HP:0002720): Decreased levels of immunoglobulin A (IgA). Evidence: IEA. (OMIM:275350)
- 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:275350)