- 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: 22/22. (PMID:11761473)
- Dystonia (HP:0001332): An abnormally increased muscular tone that causes fixed abnormal postures. There is a slow, intermittent twisting motion that leads to exaggerated turning and posture of the extremities and trunk. Evidence: PCS. Frequency: 5/13. (PMID:11761473)
- Myopathy (HP:0003198): A disorder of muscle unrelated to impairment of innervation or neuromuscular junction. Evidence: PCS. Frequency: 8/10. (PMID:11761473)
- 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: PCS. Frequency: 6/12. (PMID:11761473)
- Atrial fibrillation (HP:0005110): An atrial arrhythmia characterized by disorganized atrial activity without discrete P waves on the surface EKG, but instead by an undulating baseline or more sharply circumscribed atrial deflections of varying amplitude an frequency ranging from 350 to 600 per minute. Evidence: PCS. Frequency: 5/22. (PMID:11761473)
- Hepatomegaly (HP:0002240): Abnormally increased size of the liver. Evidence: PCS. Frequency: 5/12. (PMID:11761473)
- Elevated circulating alanine aminotransferase concentration (HP:0031964): An abnormally high concentration in the circulation of alanine aminotransferase (ALT). Evidence: PCS. Frequency: 5/15. (PMID:11761473)
- Depression (HP:0000716): Frequently experiencing feelings of being down, miserable, and/or hopeless; struggling to recover from these moods; having a pessimistic outlook on the future; feeling a pervasive sense of shame; having a low self-worth; experiencing thoughts of suicide and engaging in suicidal behavior. Evidence: PCS. (PMID:11761473)
- Personality disorder (HP:0012075): A personality disorder is a deeply ingrained pattern of behavior of a specified kind that deviates markedly from the norms of generally accepted behavior. It is typically apparent by the time of adolescence and causes long-term difficulties in personal relationships or functioning in society. Evidence: PCS. (PMID:11761473)
- Acanthocytosis (HP:0001927): Acanthocytosis is a type of poikilocytosis characterized by the presence of spikes on the cell surface. The cells have an irregular shape resembling many-pointed stars. Evidence: PCS. Frequency: 22/22. (PMID:11761473)
- Anxiety (HP:0000739): Intense feelings of nervousness, tension, or panic often arise in response to interpersonal stresses. There is worry about the negative effects of past unpleasant experiences and future negative possibilities. Individuals may feel fearful, apprehensive, or threatened by uncertainty, and they may also have fears of falling apart or losing control. Evidence: PCS. (PMID:11761473)
- Motor axonal neuropathy (HP:0007002): Progressive impairment of function of motor axons with muscle weakness, atrophy, and cramps. The deficits are length-dependent, meaning that muscles innervated by the longest nerves are affected first, so that for instance the arms are affected at a later age than the onset of deficits involving the lower leg. Evidence: IEA. (OMIM:300842)
- Increased circulating lactate dehydrogenase concentration (HP:0025435): An elevated level of the enzyme lactate dehydrogenase in the blood circulation. Evidence: PCS. Frequency: 10/11. (PMID:11761473)
- Muscle weakness (HP:0001324): Reduced strength of muscles. Evidence: PCS. Frequency: 13/20. (PMID:11761473)
- Splenomegaly (HP:0001744): Abnormal increased size of the spleen. Evidence: PCS. Frequency: 5/13. (PMID:11761473)
- 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: 2/22. (PMID:11761473)
- Decreased circulating haptoglobin concentration (HP:0020181): The concentration of haptoglobin in the blood circulation is below the lower limit of normal. Evidence: PCS. Frequency: 4/5. (PMID:11761473)
- Elevated circulating aspartate aminotransferase concentration (HP:0031956): The concentration of aspartate aminotransferase (AST) in the blood circulation is above the upper limit of normal. Evidence: PCS. Frequency: 5/15. (PMID:11761473)
- Rhabdomyolysis (HP:0003201): Breakdown of muscle fibers that leads to the release of muscle fiber contents (myoglobin) into the bloodstream. Evidence: TAS. Frequency: Occasional (HP:0040283). (OMIM:300842)
- Generalized-onset seizure (HP:0002197): A generalized-onset seizure is a type of seizure originating at some point within, and rapidly engaging, bilaterally distributed networks. The networks may include cortical and subcortical structures but not necessarily the entire cortex. Evidence: IEA. (OMIM:300842)
- Dysarthria (HP:0001260): Dysarthric speech is a general description referring to a neurological speech disorder characterized by poor articulation. Depending on the involved neurological structures, dysarthria may be further classified as spastic, flaccid, ataxic, hyperkinetic and hypokinetic, or mixed. Evidence: PCS. Frequency: 10/13. (PMID:11761473)
- Impaired vibration sensation at ankles (HP:0006938): A decrease in the ability to perceive vibration at the ankles. Clinically, this is usually tested with a tuning fork which vibrates at 128 Hz and is applied to the malleoli of the ankles. Evidence: PCS. Frequency: 6/15. (PMID:11761473)
- Adult onset (HP:0003581): Onset of disease manifestations in adulthood, defined here as at the age of 16 years or later. Evidence: PCS. Frequency: 22/22. (PMID:11761473)
- Chorea (HP:0002072): Chorea (Greek for 'dance') refers to widespread arrhythmic involuntary movements of a forcible, jerky and restless fashion. It is a random-appearing sequence of one or more discrete involuntary movements or movement fragments. Movements appear random because of variability in timing, duration or location. Each movement may have a distinct start and end. However, movements may be strung together and thus may appear to flow randomly from one muscle group to another. Chorea can involve the trunk, neck, face, tongue, and extremities. Evidence: PCS. Frequency: 18/19. (PMID:11761473)
- Elevated gamma-glutamyltransferase level (HP:0030948): Increased level of the enzyme gamma-glutamyltransferase (GGT). GGT is mainly present in kidney, liver, and pancreatic cells, but small amounts are present in other tissues. Evidence: PCS. Frequency: 4/12. (PMID:11761473)
- Dyskinesia (HP:0100660): A movement disorder which consists of effects including diminished voluntary movements and the presence of involuntary movements. Evidence: IEA. (OMIM:300842)
- Areflexia of upper limbs (HP:0012046): Inability to elicit tendon reflexes in the upper limbs. Evidence: PCS. Frequency: 8/21. (PMID:11761473)
- Compulsive behaviors (HP:0000722): Behavior that consists of repetitive acts, characterized by the feeling that one "has to" perform them, while being aware that these acts are not in line with one's overall goal. Evidence: PCS. (PMID:11761473)
- Cardiomyopathy (HP:0001638): A myocardial disorder in which the heart muscle is structurally and functionally abnormal, in the absence of coronary artery disease, hypertension, valvular disease and congenital heart disease sufficient to cause the observed myocardial abnormality. Evidence: PCS. Frequency: 4/22. (PMID:11761473)
- X-linked inheritance (HP:0001417): A mode of inheritance that is observed for traits related to a gene encoded on the X chromosome. Evidence: PCS. (PMID:11761473)
- Absent Achilles reflex (HP:0003438): Absence of the Achilles reflex (also known as the ankle jerk reflex), which can normally be elicited by tapping the tendon is tapped while the foot is dorsiflexed. Evidence: PCS. Frequency: 18/20. (PMID:11761473)
These phenotypes are associated with the disease XK-related neurodegenerative disease (OMIM:300842).