- EMG: myopathic abnormalities (HP:0003458): The presence of abnormal electromyographic patterns indicative of myopathy, such as small-short polyphasic motor unit potentials. Evidence: TAS. Frequency: Very frequent (HP:0040281). (ORPHA:603)
- 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: Very frequent (HP:0040281). (ORPHA:603)
- Distal upper limb muscle weakness (HP:0008959): Reduced strength of the distal musculature of the arms. Evidence: TAS. Frequency: Very frequent (HP:0040281). (ORPHA:603)
- 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: Very frequent (HP:0040281). (ORPHA:603)
- Weakness of long finger extensor muscles (HP:0009077). Evidence: TAS. Frequency: Very frequent (HP:0040281). (ORPHA:603)
- Clumsiness (HP:0002312): Lack of physical coordination resulting in an abnormal tendency to drop items or bump into objects. Evidence: TAS. Frequency: Frequent (HP:0040282). (ORPHA:603)
- 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: Frequent (HP:0040282). (ORPHA:603)
- Rimmed vacuoles (HP:0003805): Presence of abnormal vacuoles (membrane-bound organelles) in the sarcolemma. On histological staining with hematoxylin and eosin, rimmed vacuoles are popcorn-like clear vacuoles with a densely blue rim. The vacuoles are often associated with cytoplasmic and occasionally intranuclear eosinophilic inclusions. Evidence: TAS. Frequency: Frequent (HP:0040282). (ORPHA:603)
- Distal upper limb amyotrophy (HP:0007149): Muscular atrophy of distal arm muscles. Evidence: TAS. Frequency: Frequent (HP:0040282). (ORPHA:603)
- Mildly elevated creatine kinase (HP:0008180). Evidence: TAS. Frequency: Frequent (HP:0040282). (ORPHA:603)
- Myopathy (HP:0003198): A disorder of muscle unrelated to impairment of innervation or neuromuscular junction. Evidence: TAS. Frequency: Very frequent (HP:0040281). (ORPHA:603)
- 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:603)
These phenotypes are associated with the disease Distal myopathy, Welander type (ORPHA:603).
The following phenotypes are NOT associated with this disease:
- 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: TAS. (ORPHA:603)