- 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: IEA. (OMIM:608340)
- Ulnar claw (HP:0001178): An abnormal hand position characterized by hyperextension of the fourth and fifth fingers at the metacarpophalangeal joints and flexion of the interphalangeal joints of the same fingers such that they are curled towards the palm. Evidence: TAS. (OMIM:608340)
- Distal amyotrophy (HP:0003693): Muscular atrophy affecting muscles in the distal portions of the extremities. Evidence: TAS. (OMIM:608340)
- Infantile onset (HP:0003593): Onset of signs or symptoms of disease between 28 days to one year of life. Evidence: PCS. Frequency: 1/6. (PMID:12499475)
- Fiber type grouping (HP:0033685): An abnormal distribution of muscle fiber types in muscle tissue. Human skeletal muscle contains at least two fiber types recognizable by histochemical techniques. In transverse sections of normal skeletal muscle, type 1 and type 2 fibers are distributed in a random fashion. Grouping of fibers of the same type can be seen in certain peripheral neuropathies, thought to be due to reinnervation of denervated muscle fibers by sprouting axons. With grouping, motor units enlarge. The fibers of a motor unit, which are normally scattered, come to lie adjacent to one another. Histochemical examination shows groups of muscle fibers of the same histochemical type. Evidence: PCS. Frequency: 1/2. (PMID:12499475)
- Limb muscle weakness (HP:0003690): Reduced strength and weakness of the muscles of the arms and legs. Evidence: TAS. (OMIM:608340)
- Angulated muscle fibers (HP:0034045): Normal muscle fibers are polygonal-shaped in cross section, are multinucleated, and have minimal amounts of endomysial connective tissue. In contrast, angulated (also known as angular) muscle fibers have long and narrow vertices (corners) with sharp edges and a pointed tip. Evidence: PCS. Frequency: 1/2. (PMID:12499475)
- Childhood onset (HP:0011463): Onset of disease at the age of between 1 and 5 years. Evidence: PCS. Frequency: 5/6. (PMID:12499475)
- Lower limb muscle weakness (HP:0007340): Weakness of the muscles of the legs. Evidence: PCS. Frequency: 4/6. (PMID:12499475)
- 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: IEA. (OMIM:608340)
- Distal sensory impairment (HP:0002936): An abnormal reduction in sensation in the distal portions of the extremities. Evidence: PCS. Frequency: 3/3. (PMID:12499475)
- Type 1 muscle fiber predominance (HP:0003803): An abnormal predominance of type I muscle fibers (in general, this feature can only be observed on muscle biopsy). Evidence: PCS. Frequency: 1/2. (PMID:12499475)
- Hammertoe (HP:0001765): Hyperextension of the metatarsal-phalangeal joint with hyperflexion of the proximal interphalangeal (PIP) joint. Evidence: PCS. Frequency: 1/6. (PMID:12499475)
- Hyporeflexia (HP:0001265): Reduction of neurologic reflexes such as the knee-jerk reaction. Evidence: PCS. Frequency: 6/6. (PMID:12499475)
- EMG: neuropathic changes (HP:0003445): The presence of characteristic findings of denervation on electromyography (fibrillations, positive sharp waves, and giant motor unit potentials). Evidence: IEA. (OMIM:608340)
- Decreased number of large peripheral myelinated nerve fibers (HP:0003387): A reduced number of large myelinated nerve fibers. Evidence: PCS. Frequency: 2/2. (PMID:12499475)
- Scoliosis (HP:0002650): The presence of an abnormal lateral curvature of the spine. Evidence: TAS. (OMIM:608340)
- Talipes equinovarus (HP:0001762): Talipes equinovarus (also called clubfoot) typically has four main components: inversion and adduction of the forefoot; inversion of the heel and hindfoot; equinus (limitation of extension) of the ankle and subtalar joint; and internal rotation of the leg. Evidence: IEA. (OMIM:608340)
- 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:608340)
- Upper limb muscle weakness (HP:0003484): Weakness of the muscles of the arms. Evidence: PCS. Frequency: 3/5. (PMID:12499475)
- Onion bulb formation (HP:0003383): Repeated episodes of segmental demyelination and remyelination lead to the accumulation of supernumerary Schwann cells around axons, which is referred to as onion bulb formation. This finding affects peripheral nerves. Evidence: PCS. Frequency: 2/2. (PMID:12499475)
- Areflexia (HP:0001284): Absence of neurologic reflexes such as the knee-jerk reaction. Evidence: PCS. Frequency: 6/6. (PMID:12499475)
- Peripheral demyelination (HP:0011096): A loss of myelin from the internode regions along myelinated nerve fibers of the peripheral nervous system. Evidence: PCS. Frequency: 2/2. (PMID:12499475)
- Peripheral neuropathy (HP:0009830): Peripheral neuropathy is a general term for any disorder of the peripheral nervous system. The main clinical features used to classify peripheral neuropathy are distribution, type (mainly demyelinating versus mainly axonal), duration, and course. Evidence: PCS. Frequency: 2/2. (PMID:12499475)
- 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. (OMIM:608340)
These phenotypes are associated with the disease Charcot-Marie-Tooth disease recessive intermediate A (OMIM:608340).