Phenotypes associated with the disease Friedreich ataxia 2 (OMIM:601992):
- Abnormal EKG (HP:0003115): Abnormal rhythm of the heart. Evidence: IEA. (OMIM:601992)
- Abnormality of peripheral nerve conduction (HP:0003134): An abnormality of the conduction of electrical impulses by peripheral (motor or sensory) nerves. This finding is elicited by a nerve conduction study (NCS). Evidence: PCS. (OMIM:601992)
- Concentric hypertrophic cardiomyopathy (HP:0005157): Hypertrophic cardiomyopathy with an symmetrical and concentric pattern of hypertrophy. Evidence: TAS. (OMIM:601992)
- Mitochondrial malic enzyme reduced (HP:0003232). Evidence: IEA. (OMIM:601992)
- Abnormal spinocerebellar tract morphology (HP:0003133): An abnormality of the spinocerebellar tracts, a set of axonal fibers originating in the spinal cord and terminating in the ipsilateral cerebellum. The spinocerebellar tract convey information to the cerebellum about limb and joint position (proprioception). They comprise the ventral spinocerebellar tract, the anterior spinocerebellar tract, and the posterior spinocerebellar tract. Evidence: PCS. (OMIM:601992)
- Muscular subvalvular aortic stenosis (HP:0001691): A type of subvalvular aortic stenosis resulting from thickening of the musculature of the interventricular septum, which results in obstruction to blood flow through the left-ventricular outflow tract. Evidence: TAS. (OMIM:601992)
- 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: PCS. (OMIM:601992)
- Abnormal pyramidal tract morphology (HP:0002062): Any structural abnormality of the pyramidal tract, whose chief element, the corticospinal tract, is the only direct connection between the brain and the spinal cord. In addition to the corticospinal tract, the pyramidal system includes the corticobulbar, corticomesencephalic, and corticopontine tracts. Evidence: PCS. (OMIM:601992)
- Nystagmus (HP:0000639): Rhythmic, involuntary oscillations of one or both eyes related to abnormality in fixation, conjugate gaze, or vestibular mechanisms. Evidence: IEA. (OMIM:601992)
- Abnormal medulla oblongata morphology (HP:0011441): An abnormality of the medulla oblongata, the lower half of the brainstem. Evidence: PCS. (OMIM:601992)
- Decreased pyruvate carboxylase activity (HP:0003209): A decreased rate of pyruvate carboxylase activity. Evidence: IEA. (OMIM:601992)
- Abnormality of the cardiovascular system (HP:0001626): Any abnormality of the cardiovascular system. Evidence: TAS. (OMIM:601992)
- Hammertoe (HP:0001765): Hyperextension of the metatarsal-phalangeal joint with hyperflexion of the proximal interphalangeal (PIP) joint. Evidence: IEA. (OMIM:601992)
- Incoordination (HP:0002311): A deficit in coordination of muscle movements. Coordination is defined as the orchestrated movement of multiple body parts as required to accomplish intended actions, like walking. Evidence: IEA. (OMIM:601992)
- Juvenile onset (HP:0003621): Onset of signs or symptoms of disease between the age of 5 and 15 years. Evidence: PCS. (OMIM:601992)
- Scoliosis (HP:0002650): The presence of an abnormal lateral curvature of the spine. Evidence: IEA. (OMIM:601992)
- Pes cavus (HP:0001761): An increase in height of the medial longitudinal arch of the foot that does not flatten on weight bearing (i.e., a distinctly hollow form of the sole of the foot when it is bearing weight). Evidence: IEA. (OMIM:601992)
- Babinski sign (HP:0003487): Upturning of the big toe (and sometimes fanning of the other toes) in response to stimulation of the sole of the foot. If the Babinski sign is present it can indicate damage to the corticospinal tract. Evidence: TAS. (OMIM:601992)
- 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: IEA. (OMIM:601992)
- Impaired vibratory sensation (HP:0002495): A decrease in the ability to perceive vibration. Clinically, this is usually tested with a tuning fork which vibrates at 128 Hz and is applied to bony prominences such as the malleoli at the ankles or the metacarpal-phalangeal joints. There is a slow decay of vibration from the tuning fork. The degree of vibratory sense loss can be crudely estimated by counting the number of seconds that the examiner can perceive the vibration longer than the patient. Evidence: IEA. (OMIM:601992)
- Abnormal spinal cord dorsal column morphology (HP:0011397): An abnormality of the dorsal columns, i.e., of the dorsal portion of the gray substance of the spinal cord. The dorsal column consists of the fasciculus gracilis and fasciculus cuneatus and itself is part of the dorsal funiculus. Evidence: PCS. (OMIM:601992)
- 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: TAS. (OMIM:601992)
- 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:601992)
- Diabetic ketoacidosis (HP:0001953): A type of diabetic metabolic abnormality with an accumulation of ketone bodies. Evidence: IEA. (OMIM:601992)
- Diminished deep tendon reflex (HP:0001315): A reduction (hyporeflexia) or complete absence (areflexia) of the involuntary muscle contraction normally elicited by a reflex stimulus, such as tapping a deep tendon. Evidence: PCS. (OMIM:601992)