Phenotypes associated with the disease Charcot-Marie-Tooth disease type 1C (OMIM:601098):
- Hyporeflexia (HP:0001265): Reduction of neurologic reflexes such as the knee-jerk reaction. Evidence: TAS. (OMIM:601098)
- Paresthesia (HP:0003401): Abnormal sensations such as tingling, pricking, or numbness of the skin with no apparent physical cause. Evidence: PCS. Frequency: 1/2. (PMID:19541485)
- Juvenile onset (HP:0003621): Onset of signs or symptoms of disease between the age of 5 and 15 years. Evidence: PCS. Frequency: 1/2. (PMID:19541485)
- Hypoesthesia (HP:0033748): Decreased ability to perceive touch. Evidence: PCS. Frequency: 2/2. (PMID:19541485)
- Middle age onset (HP:0003596): A type of adult onset with onset of symptoms at the age of 40 to 60 years. Evidence: PCS. Frequency: 1/2. (PMID:19541485)
- Decreased motor nerve conduction velocity (HP:0003431): A type of decreased nerve conduction velocity that affects the motor neuron. Evidence: PCS. Frequency: 2/2. (PMID:19541485)
- 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: PCS. Frequency: 1/2. (PMID:19541485)
- Distal amyotrophy (HP:0003693): Muscular atrophy affecting muscles in the distal portions of the extremities. Evidence: TAS. (OMIM:601098)
- Polyneuropathy (HP:0001271): A generalized disorder of peripheral nerves. Evidence: PCS. Frequency: 2/2. (PMID:19541485)
- Gait ataxia (HP:0002066): A type of ataxia characterized by the impairment of the ability to coordinate the movements required for normal walking. Gait ataxia is characteirzed by a wide-based staggering gait with a tendency to fall. Evidence: PCS. Frequency: 2/2. (PMID:19541485)
- 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: TAS. (OMIM:601098)
- Distal muscle weakness (HP:0002460): Reduced strength of the musculature of the distal extremities. Evidence: TAS. (OMIM:601098)
- 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. Frequency: 1/2. (PMID:19541485)
- Segmental peripheral demyelination/remyelination (HP:0003481): A segmental pattern of demyelination and regeneration (remyelination) affecting peripheral nerves. Evidence: TAS. (OMIM:601098)
- Hypertrophic nerve changes (HP:0003382). Evidence: TAS. (OMIM:601098)
- Sensorimotor neuropathy (HP:0007141). Evidence: PCS. Frequency: 2/2. (PMID:19541485)
- Decreased distal sensory nerve action potential (HP:0007230): A reduction in the amplitude of sensory nerve action potential in distal nerve segments. This feature is measured by nerve conduction studies. Evidence: PCS. Frequency: 2/2. (PMID:19541485)
- Distal sensory impairment (HP:0002936): An abnormal reduction in sensation in the distal portions of the extremities. Evidence: TAS. (OMIM:601098)
- Positive Romberg sign (HP:0002403): The patient stands with the feet placed together and balance and is asked to close his or her eyes. A loss of balance upon eye closure is a positive Romberg sign and is interpreted as indicating a deficit in proprioception. Evidence: PCS. Frequency: 1/2. (PMID:19541485)
- Decreased nerve conduction velocity (HP:0000762): A reduction in the speed at which electrical signals propagate along the axon of a neuron. Evidence: PCS. Frequency: 2/2. (PMID:19541485)
- Autosomal dominant inheritance (HP:0000006): 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 heterozygotes. In the context of medical genetics, an autosomal dominant disorder is caused when a single copy of the mutant allele is present. Males and females are affected equally, and can both transmit the disorder with a risk of 50% for each child of inheriting the mutant allele. Evidence: PCS. (PMID:12525712)