- Myocarditis (HP:0012819): Inflammation of the myocardium. Evidence: PCS. (PMID:27523598)
- Myocardial fibrosis (HP:0001685): Myocardial fibrosis is characterized by dysregulated collagen turnover (increased synthesis predominates over unchanged or decreased degradation) and excessive diffuse collagen accumulation in the interstitial and perivascular spaces as well as by phenotypically transformed fibroblasts, termed myofibroblasts. Evidence: PCS. Frequency: 1/6. (PMID:27523598)
- Bradycardia (HP:0001662): A slower than normal heart rate (in adults, slower than 60 beats per minute). Evidence: PCS. Frequency: 3/7. (PMID:27523598)
- 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: Occasional (HP:0040283). (OMIM:617222)
- Hypertrophic cardiomyopathy (HP:0001639): Hypertrophic cardiomyopathy (HCM) is defined by the presence of increased ventricular wall thickness or mass in the absence of loading conditions (hypertension, valve disease) sufficient to cause the observed abnormality. Evidence: PCS. Frequency: 1/7. (PMID:27523598)
- Childhood onset (HP:0011463): Onset of disease at the age of between 1 and 5 years. Evidence: PCS. Frequency: 5/7. (PMID:27523598)
- 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: 1/7. (PMID:27523598)
- Infantile onset (HP:0003593): Onset of signs or symptoms of disease between 28 days to one year of life. Evidence: PCS. Frequency: 2/7. (PMID:27523598)
- 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:27523598)
- Congestive heart failure (HP:0001635): The presence of an abnormality of cardiac function that is responsible for the failure of the heart to pump blood at a rate that is commensurate with the needs of the tissues or a state in which abnormally elevated filling pressures are required for the heart to do so. Heart failure is frequently related to a defect in myocardial contraction. Evidence: TAS. (OMIM:617222)
- 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. Frequency: Occasional (HP:0040283). (OMIM:617222)
- Sudden cardiac death (HP:0001645): The heart suddenly and unexpectedly stops beating resulting in death within a short time period (generally within 1 h of symptom onset). Evidence: PCS. Frequency: 7/7. (PMID:27523598)
These phenotypes are associated with the disease sudden cardiac failure, infantile (OMIM:617222).