- Joint hypermobility (HP:0001382): The capability that a joint (or a group of joints) has to move, passively and/or actively, beyond normal limits along physiological axes. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:37553)
- Periodic paralysis (HP:0003768): Episodes of muscle weakness. Evidence: TAS. Frequency: Obligate (HP:0040280). (ORPHA:37553)
- Episodic flaccid weakness (HP:0003752): Recurrent episodes of muscle flaccidity, a type of paralysis in which a muscle becomes soft and yields to passive stretching. Evidence: TAS. Frequency: Very frequent (HP:0040281). (ORPHA:37553)
- Abnormality of the dentition (HP:0000164): Any abnormality of the teeth. Evidence: TAS. Frequency: Frequent (HP:0040282). (ORPHA:37553)
- Micrognathia (HP:0000347): Developmental hypoplasia of the mandible. Evidence: TAS. Frequency: Frequent (HP:0040282). (ORPHA:37553)
- Prolonged QT interval (HP:0001657): Increased time between the start of the Q wave and the end of the T wave as measured by the electrocardiogram (EKG). Evidence: TAS. Frequency: Frequent (HP:0040282). (ORPHA:37553)
- Abnormal facial shape (HP:0001999): An abnormal morphology (form) of the face or its components. Evidence: TAS. Frequency: Frequent (HP:0040282). (ORPHA:37553)
- Ventricular arrhythmia (HP:0004308). Evidence: TAS. Frequency: Frequent (HP:0040282). (ORPHA:37553)
- Short stature (HP:0004322): A height below that which is expected according to age and gender norms. Although there is no universally accepted definition of short stature, many refer to "short stature" as height more than 2 standard deviations below the mean for age and gender (or below the 3rd percentile for age and gender dependent norms). Evidence: TAS. Frequency: Frequent (HP:0040282). (ORPHA:37553)
- Periodic hypokalemic paresis (HP:0008153): Episodes of muscle weakness associated with reduced levels of potassium in the blood. Evidence: TAS. Frequency: Frequent (HP:0040282). (ORPHA:37553)
- High palate (HP:0000218): Height of the palate more than 2 SD above the mean (objective) or palatal height at the level of the first permanent molar more than twice the height of the teeth (subjective). Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:37553)
- Thin upper lip vermilion (HP:0000219): Height of the vermilion of the upper lip in the midline more than 2 SD below the mean. Alternatively, an apparently reduced height of the vermilion of the upper lip in the frontal view (subjective). Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:37553)
- Hypertelorism (HP:0000316): Interpupillary distance more than 2 SD above the mean (alternatively, the appearance of an increased interpupillary distance or widely spaced eyes). Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:37553)
- Facial asymmetry (HP:0000324): An abnormal difference between the left and right sides of the face. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:37553)
- Triangular face (HP:0000325): Facial contour, as viewed from the front, triangular in shape, with breadth at the temples and tapering to a narrow chin. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:37553)
- Hypoplasia of the maxilla (HP:0000327): Abnormally small dimension of the Maxilla. Usually creating a malocclusion or malalignment between the upper and lower teeth or resulting in a deficient amount of projection of the base of the nose and lower midface region. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:37553)
- Broad forehead (HP:0000337): Width of the forehead or distance between the frontotemporales is more than two standard deviations above the mean (objective); or apparently increased distance between the two sides of the forehead. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:37553)
- Low-set ears (HP:0000369): Upper insertion of the ear to the scalp below an imaginary horizontal line drawn between the inner canthi of the eye and extending posteriorly to the ear. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:37553)
- Bulbous nose (HP:0000414): Increased volume and globular shape of the anteroinferior aspect of the nose. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:37553)
- Wide nasal bridge (HP:0000431): Increased breadth of the nasal bridge (and with it, the nasal root). Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:37553)
- Oligodontia (HP:0000677): The absence of six or more teeth from the normal series by a failure to develop. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:37553)
- Dental crowding (HP:0000678): Changes in alignment of teeth in the dental arch. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:37553)
- Increased circulating aldosterone concentration (HP:0000859): Overproduction of the mineralocorticoid aldosterone by the adrenal cortex. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:37553)
- 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). (ORPHA:37553)
- Specific learning disability (HP:0001328): Impairment of certain skills such as reading or writing, coordination, self-control, or attention that interfere with the ability to learn. The impairment is not related to a global deficiency of intelligence. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:37553)
- Growth delay (HP:0001510): A deficiency or slowing down of growth pre- and postnatally. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:37553)
- 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: TAS. Frequency: Occasional (HP:0040283). (ORPHA:37553)
- Torsade de pointes (HP:0001664): A type of ventricular tachycardia characterized by polymorphioc QRS complexes that change in amplitue and cycle length, and thus have the appearance of oscillating around the baseline in the EKG. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:37553)
- Short foot (HP:0001773): A measured foot length that is more than 2 SD below the mean for a newborn of 27 - 41 weeks gestation, or foot that is less than the 3rd centile for individuals from birth to 16 years of age (objective). Alternatively, a foot that appears disproportionately short (subjective). Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:37553)
- Clinodactyly of the 5th toe (HP:0001864): Bending or curvature of a fifth toe in the tibial direction (i.e., towards the big toe). Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:37553)
- Palpitations (HP:0001962): A sensation that the heart is pounding or racing, which is a non-specific sign but may be a manifestation of arrhythmia. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:37553)
- Scoliosis (HP:0002650): The presence of an abnormal lateral curvature of the spine. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:37553)
- 2-3 toe syndactyly (HP:0004691): Syndactyly with fusion of toes two and three. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:37553)
- Abnormal T-wave (HP:0005135): An abnormality of the T wave on the electrocardiogram, which mainly represents the repolarization of the ventricles. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:37553)
- Bidirectional ventricular ectopy (HP:0005147). Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:37553)
- Prolonged QTc interval (HP:0005184): A longer than normal interval (corrected for heart rate) between the Q and T waves in the heart's cycle. Prolonged QTc can cause premature action potentials during late phase depolarizations thereby leading to ventricular arrhythmias and ventricular fibrillations. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:37553)
- Persistence of primary teeth (HP:0006335): Persistence of the primary teeth beyond the age by which they normally are shed and replaced by the permanent teeth. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:37553)
- Premature ventricular contraction (HP:0006682): Premature ventricular contractions (PVC) or ventricular extrasystoles are premature contractions of the heart that arise in response to an impulse in the ventricles rather than the normal impulse from the sinoatrial (SA) node. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:37553)
- Polymorphic and polytopic ventricular extrasystoles (HP:0006696). Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:37553)
- Periodic hyperkalemic paralysis (HP:0007215): Episodes of muscle weakness associated with elevated levels of potassium in the blood. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:37553)
- Abnormality of dental color (HP:0011073): A developmental defect of tooth color. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:37553)
- Short palpebral fissure (HP:0012745): Distance between the medial and lateral canthi is more than 2 SD below the mean for age (objective); or, apparently reduced length of the palpebral fissures. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:37553)
- 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: Occasional (HP:0040283). (ORPHA:37553)
- Prominent U wave (HP:0025072): Increased amplitude of the U wave, defined as an amplitude greater than 1-2mm or 25 percent of the height of the T wave. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:37553)
- Scaphocephaly (HP:0030799): Scaphocephaly is a subtype of dolichocephaly where the anterior and posterior aspects of the cranial vault are pointed (boat-shaped). Scaphocephaly is caused by a precocious fusion of sagittal suture without other associated synostosis. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:37553)
- Polymorphic ventricular tachycardia (HP:0031677): A type of ventricular tachycardia that is characterized by variable QRS complexes within each lead (i.e., QRS complexes may be different from beat to beat). Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:37553)
- Small hand (HP:0200055): Disproportionately small hand. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:37553)
- Renal hypoplasia (HP:0000089): Hypoplasia of the kidney. Evidence: TAS. Frequency: Very rare (HP:0040284). (ORPHA:37553)
- Renal tubular dysfunction (HP:0000124): Abnormal function of the renal tubule. The basic functional unit of the kidney, the nephron, consists of a renal corpuscle attached to a renal tubule, with roughly 0.8 to 1.5 nephrons per adult kidney. The functions of the renal tubule include reabsorption of water, electrolytes, glucose, and amino acids and secretion of substances such as uric acid. Evidence: TAS. Frequency: Very rare (HP:0040284). (ORPHA:37553)
- Syncope (HP:0001279): A transient loss of consciousness (i.e., characterized by a rapid onset, a short duration, and a spontaneous and complete recovery) due to cerebral hypoperfusion. Evidence: TAS. Frequency: Very rare (HP:0040284). (ORPHA:37553)
- Muscle weakness (HP:0001324): Reduced strength of muscles. Evidence: TAS. Frequency: Obligate (HP:0040280). (ORPHA:37553)
These phenotypes are associated with the disease Andersen-Tawil syndrome (ORPHA:37553).