- Clonus (HP:0002169): A series of rhythmic and involuntary muscle contractions (at a frequency of about 5 to 7 Hz) that occur in response to an abruptly applied and sustained stretch. Evidence: PCS. Frequency: 12/12. (PMID:23365102)
- Tented upper lip vermilion (HP:0010804): Triangular appearance of the oral aperture with the apex in the midpoint of the upper vermilion and the lower vermilion forming the base. Evidence: PCS. Frequency: 7/13. (PMID:23365102)
- Elevated circulating creatine kinase activity (HP:0003236): The activity of creatine kinase in the blood circulation is above the upper limit of normal. Evidence: PCS. Frequency: 10/13. (PMID:23365102)
- Facial palsy (HP:0010628): Facial nerve palsy is a dysfunction of cranial nerve VII (the facial nerve) that results in inability to control facial muscles on the affected side with weakness of the muscles of facial expression and eye closure. This can either be present in unilateral or bilateral form. Evidence: PCS. Frequency: 2/13. (PMID:23365102)
- Hepatomegaly (HP:0002240): Abnormally increased size of the liver. Evidence: PCS. Frequency: 4/4. (PMID:32453731)
- Generalized hypotonia (HP:0001290): Generalized muscular hypotonia (abnormally low muscle tone). Evidence: PCS. Frequency: 4/4. (PMID:32453731)
- Right atrial enlargement (HP:0030718): Increase in size of the right atrium. Evidence: PCS. Frequency: 1/1. (PMID:32453731)
- Left atrial enlargement (HP:0031295): Increase in size of the left atrium. Evidence: PCS. Frequency: 1/1. (PMID:32453731)
- Restrictive cardiomyopathy (HP:0001723): Restrictive left ventricular physiology is characterized by a pattern of ventricular filling in which increased stiffness of the myocardium causes ventricular pressure to rise precipitously with only small increases in volume, defined as restrictive ventricular physiology in the presence of normal or reduced diastolic volumes (of one or both ventricles), normal or reduced systolic volumes, and normal ventricular wall thickness. Evidence: PCS. Frequency: 2/13. (PMID:23365102)
- Death in infancy (HP:0001522): Death within the first 24 months of life. Evidence: PCS. Frequency: 13/13. (PMID:23365102)
- 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: 7/13. (PMID:23365102)
- Neonatal onset (HP:0003623): Onset of signs or symptoms of disease within the first 28 days of life. Evidence: PCS. Frequency: 17/17. (PMID:23365102;PMID:32453731)
- Generalized muscle weakness (HP:0003324): Generalized weakness or decreased strength of the muscles, affecting both distal and proximal musculature. Evidence: PCS. Frequency: 13/13. Onset: Neonatal onset (HP:0003623). (PMID:23365102)
- Myofiber disarray (HP:0031318): A nonparallel arrangement of cardiac myocytes. Evidence: PCS. Frequency: 11/11. (PMID:23365102;PMID:32453731)
- Cardiogenic shock (HP:0030149): Severely decreased cardiac output with evidence of inadequate end-organ perfusion (i.e., tissue hypoxia) in the presence of adequate intravascular volume. Evidence: PCS. Frequency: 2/4. (PMID:32453731)
- 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: 1/1. (PMID:32453731)
- Biventricular hypertrophy (HP:0200128): Thickening of the heart walls in both ventricles. Evidence: PCS. Frequency: 1/1. (PMID:32453731)
- Left ventricular noncompaction cardiomyopathy (HP:0011664): Left ventricular non-compaction (LVNC) is characterized by prominent left ventricular trabeculae and deep inter-trabecular recesses. The myocardial wall is often thickened with a thin, compacted epicardial layer and a thickened endocardial layer. In some patients, LVNC is associated with left ventricular dilatation and systolic dysfunction, which can be transient in neonates. Evidence: PCS. Frequency: 2/13. (PMID:23365102)
- 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: 6/13. (PMID:23365102)
- Ptosis (HP:0000508): The upper eyelid margin is positioned 3 mm or more lower than usual and covers the superior portion of the iris (objective); or, the upper lid margin obscures at least part of the pupil (subjective). Evidence: PCS. Frequency: 1/13. (PMID:23365102)
- 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:23365102)
- Cardiorespiratory arrest (HP:0006543). Evidence: PCS. Frequency: 2/4. Onset: Neonatal onset (HP:0003623). (PMID:32453731)
- Mitral regurgitation (HP:0001653): An abnormality of the mitral valve characterized by insufficiency or incompetence of the mitral valve resulting in retrograde leaking of blood through the mitral valve upon ventricular contraction. Evidence: PCS. Frequency: 2/4. (PMID:32453731)
- Tremor (HP:0001337): An unintentional, oscillating to-and-fro muscle movement about a joint axis. Evidence: PCS. Frequency: 12/12. (PMID:23365102)
- Type 1 fibers relatively smaller than type 2 fibers (HP:0003755): The presence of abnormal muscle fiber size such that type 1 fibers are smaller than type 2 fibers. Evidence: PCS. Frequency: 13/13. (PMID:23365102)
These phenotypes are associated with the disease myopathy, myofibrillar, 12, infantile-onset, with cardiomyopathy (OMIM:619424).