- Progressive (HP:0003676): Applies to a disease manifestation that increases in scope or severity over the course of time, i.e., that worsens with age. Evidence: PCS. (PMID:26078401)
- Juvenile onset (HP:0003621): Onset of signs or symptoms of disease between the age of 5 and 15 years. Evidence: PCS. Frequency: 3/3. (PMID:26078401)
- Decreased motor nerve conduction velocity (HP:0003431): A type of decreased nerve conduction velocity that affects the motor neuron. Evidence: PCS. Frequency: 1/1. (PMID:26078401)
- 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:605726)
- 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: PCS. Frequency: 2/3. (PMID:26078401)
- Distal amyotrophy (HP:0003693): Muscular atrophy affecting muscles in the distal portions of the extremities. Evidence: PCS. Frequency: 3/3. (PMID:26078401)
- Distal muscle weakness (HP:0002460): Reduced strength of the musculature of the distal extremities. Evidence: PCS. Frequency: 3/3. (PMID:26078401)
- Claw hand deformity (HP:0034337): An abnormality of the hand characterized by metacarpophalangeal (MCP) hyperextension and proximal interphalangeal (PIP) and distal interphalangeal (DIP) flexion. The position of the affected hand is said to resemble a claw. Evidence: PCS. Frequency: 1/3. (PMID:26078401)
- Hyperactive patellar reflex (HP:0007083). Evidence: PCS. Frequency: 3/3. (PMID:26078401)
- Decreased compound muscle action potential amplitude (HP:0033383): Reduced level of the compound muscle action potential (CMAP), which is recorded following electrical stimulation of a nerve from surface electrodes overlying a muscle supplied by that nerve. Evidence: PCS. Frequency: 1/1. (PMID:26078401)
- 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: PCS. Frequency: 3/3. (PMID:26078401)
- 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: PCS. (PMID:26078401)
- Spinal muscular atrophy (HP:0007269): Muscular weakness and atrophy related to loss of the motor neurons of the spinal cord and brainstem. Evidence: PCS. (PMID:26078401)
- 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: 3/3. (PMID:26078401)
- Hammertoe (HP:0001765): Hyperextension of the metatarsal-phalangeal joint with hyperflexion of the proximal interphalangeal (PIP) joint. Evidence: TAS. (OMIM:605726)
These phenotypes are associated with the disease autosomal recessive distal spinal muscular atrophy 2 (OMIM:605726).