- Myokymia (HP:0002411): Myokymia consists of involuntary, fine, continuous, undulating contractions that spread across the affected striated muscle. Evidence: TAS. Frequency: Very frequent (HP:0040281). (ORPHA:324442)
- Myotonia (HP:0002486): An involuntary and painless delay in the relaxation of skeletal muscle following contraction or electrical stimulation. Evidence: TAS. Frequency: Very frequent (HP:0040281). (ORPHA:324442)
- EMG: chronic denervation signs (HP:0003444): Evidence of chronic denervation on electromyography. Evidence: TAS. Frequency: Very frequent (HP:0040281). (ORPHA:324442)
- Distal lower limb muscle weakness (HP:0009053): Reduced strength of the distal musculature of the legs. Evidence: TAS. Frequency: Very frequent (HP:0040281). (ORPHA:324442)
- EMG: myokymic discharges (HP:0100288): The presence of spontaneous bursts of rapidly firing potentials that recur at regular intervals of 2-10 per second and are unaffected by voluntary effort. This is an electromyographic (EMG) finding. Evidence: TAS. Frequency: Very frequent (HP:0040281). (ORPHA:324442)
- Gait disturbance (HP:0001288): The term gait disturbance can refer to any disruption of the ability to walk. Evidence: TAS. Frequency: Frequent (HP:0040282). (ORPHA:324442)
- 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: TAS. Frequency: Frequent (HP:0040282). (ORPHA:324442)
- Abnormal foot morphology (HP:0001760): An abnormality of the skeleton of foot. Evidence: TAS. Frequency: Frequent (HP:0040282). (ORPHA:324442)
- Frequent falls (HP:0002359). Evidence: TAS. Frequency: Frequent (HP:0040282). (ORPHA:324442)
- Elevated circulating creatine kinase activity (HP:0003236): The activity of creatine kinase in the blood circulation is above the upper limit of normal. Evidence: TAS. Frequency: Frequent (HP:0040282). (ORPHA:324442)
- 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: TAS. Frequency: Frequent (HP:0040282). (ORPHA:324442)
- Exercise intolerance (HP:0003546): A functional motor deficit where individuals whose responses to the challenges of exercise fail to achieve levels considered normal for their age and gender. Evidence: TAS. Frequency: Frequent (HP:0040282). (ORPHA:324442)
- Exercise-induced muscle cramps (HP:0003710): Sudden and involuntary contractions of one or more muscles brought on by physical exertion. Evidence: TAS. Frequency: Frequent (HP:0040282). (ORPHA:324442)
- 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: TAS. Frequency: Frequent (HP:0040282). (ORPHA:324442)
- Motor polyneuropathy (HP:0007178). Evidence: TAS. Frequency: Frequent (HP:0040282). (ORPHA:324442)
- Limb fasciculations (HP:0007289): Fasciculations affecting the musculature of the arms and legs. Evidence: TAS. Frequency: Frequent (HP:0040282). (ORPHA:324442)
- Handgrip myotonia (HP:0012899): Difficulty releasing one's grip associated with prolonged first handgrip relaxation times. Evidence: TAS. Frequency: Frequent (HP:0040282). (ORPHA:324442)
- Fatigable weakness of distal limb muscles (HP:0030198): A type of weakness of a skeletal muscle of distal part of a limb that occurs after a muscle group is used and lessens if the muscle group has some rest. That is, there is diminution of strength with repetitive muscle actions. Evidence: TAS. Frequency: Frequent (HP:0040282). (ORPHA:324442)
- Areflexia (HP:0001284): Absence of neurologic reflexes such as the knee-jerk reaction. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:324442)
- Flexion contracture (HP:0001371): A flexion contracture is a bent (flexed) joint that cannot be straightened actively or passively. It is thus a chronic loss of joint motion due to structural changes in muscle, tendons, ligaments, or skin that prevents normal movement of joints. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:324442)
- 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: TAS. Frequency: Occasional (HP:0040283). (ORPHA:324442)
- Achilles tendon contracture (HP:0001771): A contracture of the Achilles tendon. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:324442)
- Impaired vibration sensation in the lower limbs (HP:0002166): A decrease in the ability to perceive vibration in the legs. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:324442)
- Tetraparesis (HP:0002273): Weakness of all four limbs. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:324442)
- Writer's cramp (HP:0002356): A focal dystonia of the fingers, hand, and/or forearm that appears when the affected person attempts to do a task that requires fine motor movements such as writing or playing a musical instrument. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:324442)
- Loss of ambulation (HP:0002505): Inability to walk in a person who previous had the ability to walk. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:324442)
- Steppage gait (HP:0003376): An abnormal gait pattern that arises from weakness of the pretibial and peroneal muscles due to a lower motor neuron lesion. Affected patients have footdrop and are unable to dorsiflex and evert the foot. The leg is lifted high on walking so that the toes clear the ground, and there may be a slapping noise when the foot strikes the ground again. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:324442)
- Sensory axonal neuropathy (HP:0003390): An axonal neuropathy of peripheral sensory nerves. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:324442)
- Paresthesia (HP:0003401): Abnormal sensations such as tingling, pricking, or numbness of the skin with no apparent physical cause. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:324442)
- Distal sensory impairment of all modalities (HP:0003409): Reduced ability to sense pain, temperature, touch, vibration stimuli in the distal regions of the extremities. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:324442)
- Muscle stiffness (HP:0003552): A condition in which muscles cannot be moved quickly without accompanying pain or spasm. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:324442)
- Percussion-induced rapid rolling muscle contractions (HP:0003760): Mechanical percussion (i.e., striking a muscle with a reflex hammer) leads to spreading waves of muscle contractions that begin proximally and spread laterally across the muscle. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:324442)
- Distal lower limb amyotrophy (HP:0008944): Muscular atrophy of distal leg muscles. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:324442)
- Intrinsic hand muscle atrophy (HP:0008954): Atrophy of the intrinsic muscle groups of the hand, comprising the thenar and hypothenar muscles; the interossei muscles; and the lumbrical muscles. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:324442)
- Exercise-induced leg cramps (HP:0008991): Sudden and involuntary contractions of one or more muscles of the leg brought on by physical exertion. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:324442)
- Weakness of the intrinsic hand muscles (HP:0009005). Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:324442)
- Foot dorsiflexor weakness (HP:0009027): Weakness of the muscles responsible for dorsiflexion of the foot, that is, of the movement of the toes towards the shin. The foot dorsiflexors include the tibialis anterior, the extensor hallucis longus, the extensor digitorum longus, and the peroneus tertius muscles. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:324442)
- Peroneal muscle atrophy (HP:0009049): Atrophy of the peroneous muscles, peroneus longus (also known as Fibularis longus), Peroneus brevis (also known as fibularis brevis, and Peroneus tertius (also known as fibularis tertius). Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:324442)
- Weakness of long finger extensor muscles (HP:0009077). Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:324442)
- Hand muscle atrophy (HP:0009130): Muscular atrophy involving the muscles of the hand. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:324442)
- Hyperhidrosis (HP:0000975): Abnormal excessive perspiration (sweating) despite the lack of appropriate stimuli like hot and humid weather. Evidence: TAS. Frequency: Very rare (HP:0040284). (ORPHA:324442)
- Split hand (HP:0001171): A condition in which middle parts of the hand (fingers and metacarpals) are missing giving a cleft appearance. The severity is very variable ranging from slightly hypoplastic middle fingers over absent middle fingers as far as oligo- or monodactyl hands. Evidence: TAS. Frequency: Very rare (HP:0040284). (ORPHA:324442)
- Mild intellectual disability (HP:0001256): Mild intellectual disability (ID) is defined as a type of ID characterized by mildly sub-average adaptive functioning and intellectual functioning, with an intelligence quotient (IQ) the range of 50-69. Evidence: TAS. Frequency: Very rare (HP:0040284). (ORPHA:324442)
- 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: Very rare (HP:0040284). (ORPHA:324442)
- Thoracic scoliosis (HP:0002943). Evidence: TAS. Frequency: Very rare (HP:0040284). (ORPHA:324442)
- Short third metatarsal (HP:0004686): Underdevelopment of the Third metatarsal bone leading to a short (hypoplastic) third metatarsal bone. Evidence: TAS. Frequency: Very rare (HP:0040284). (ORPHA:324442)
- Camptodactyly of finger (HP:0100490): The distal interphalangeal joint and/or the proximal interphalangeal joint of the fingers cannot be extended to 180 degrees by either active or passive extension. Evidence: TAS. Frequency: Very rare (HP:0040284). (ORPHA:324442)
These phenotypes are associated with the disease Autosomal recessive axonal neuropathy with neuromyotonia (ORPHA:324442).