Traits

Traits linked to PMP22

peripheral myelin protein 22

The Human Phenotype Ontology links 121 traits to PMP22, by body system: features seen in people with one of the gene's rare conditions.

PMP22

Abnormality of the nervous system

Trait	How often it is seen
Abnormal gait	Always
Absent reflexes	Always
Acute demyelinating polyneuropathy	Always
Axonal loss	Always
Decreased motor nerve conduction velocity	Always
Decreased reflex response	Always
Decreased sensation in extremities	Always
Decreased sensory nerve conduction velocity	Always
Froment sign	Always
Hand tingling	Always
Impaired distal vibration sensation	Always
Motor delay	Always
Myelin tomacula	Always
Numbness	Always
Onion bulb formation	Always
Peripheral demyelination	Always
Segmental peripheral demyelination/remyelination	Always
Sensory ataxia	Always
Tremor	Always
Wide based walk	Always
Decreased nerve conduction velocity	Very often (80–99%)
Demyelinating peripheral neuropathy	Very often (80–99%)
Peripheral neuropathy	Very often (80–99%)
Abnormality of pain sensation	Often (30–79%)
Acroparesthesia	Often (30–79%)
Balance impairment	Often (30–79%)
Clumsiness	Often (30–79%)
Dysesthesia	Often (30–79%)
Impaired pain sensation	Often (30–79%)
Impaired temperature sensation	Often (30–79%)
Impaired touch sensation	Often (30–79%)
Impaired vibration sensation in the lower limbs	Often (30–79%)
Impaired vibratory sensation	Often (30–79%)
Inability to coordinate movements when walking	Often (30–79%)
Limb ataxia	Often (30–79%)
Nerve damage causing decreased feeling and movement	Often (30–79%)
Pins and needles feeling	Often (30–79%)
Postural tremor	Often (30–79%)
Somatic sensory dysfunction	Often (30–79%)
Unsteady walk	Often (30–79%)
Abnormality of balance	Sometimes (5–29%)
Babinski sign	Sometimes (5–29%)
Cranial nerve paralysis	Sometimes (5–29%)
Global developmental delay	Sometimes (5–29%)
High stepping	Sometimes (5–29%)
Inability to move vocal cords	Sometimes (5–29%)
Inability to walk	Sometimes (5–29%)
Spontaneous pain sensation	Sometimes (5–29%)
Hyperactive deep tendon reflexes	Rarely (1–4%)
Action tremor	Not recorded
Decreased number of peripheral myelinated nerve fibers	Not recorded
Hypertrophic nerve changes	Not recorded
Myelin outfoldings	Not recorded
Upper limb postural tremor	Not recorded

Abnormality of limbs

Trait	How often it is seen
Distal lower limb muscle weakness	Always
Dropped arches	Always
Foot drop	Always
Hand muscle weakness	Always
Limb muscle weakness	Always
Thenar muscle atrophy	Always
Thenar muscle weakness	Always
Areflexia of lower limbs	Often (30–79%)
Club feet	Often (30–79%)
Decreased/absent ankle reflexes	Often (30–79%)
Hand muscle degeneration	Often (30–79%)
High-arched foot	Often (30–79%)
Hyporeflexia of lower limbs	Often (30–79%)
Hyporeflexia of upper limbs	Often (30–79%)
Lower limb muscle weakness	Often (30–79%)
Peroneal muscle atrophy	Often (30–79%)
Peroneal muscle weakness	Often (30–79%)
Underdeveloped calf muscles	Often (30–79%)
Equinovarus deformity	Sometimes (5–29%)
Hammertoe	Sometimes (5–29%)
Increased size of calf muscles	Sometimes (5–29%)
Intrinsic hand muscle atrophy	Sometimes (5–29%)
Joint contracture of the hand	Sometimes (5–29%)
Knock knees	Sometimes (5–29%)
Split hand	Sometimes (5–29%)
Talipes calcaneovarus	Sometimes (5–29%)
Talipes calcaneovalgus	Not recorded
Ulnar claw	Not recorded

Abnormality of the musculoskeletal system

Trait	How often it is seen
Ankle weakness	Always
Distal muscle wasting	Always
Proximal neurogenic muscle weakness	Always
Scoliosis	Always
Weakness of outermost muscles	Always
Distal lower limb amyotrophy	Often (30–79%)
EMG: neuropathic changes	Often (30–79%)
Generalized decreased muscle tone	Often (30–79%)
Kyphoscoliosis	Often (30–79%)
Muscle degeneration	Often (30–79%)
Muscle weakness	Often (30–79%)
Frequent falls	Sometimes (5–29%)
Muscle spasm	Sometimes (5–29%)
Scapuloperoneal weakness	Sometimes (5–29%)
Weak diaphragm	Sometimes (5–29%)
Cold-induced muscle cramps	Not recorded
Low muscle tone	Not recorded

Abnormality of the eye

Trait	How often it is seen
Abnormality of the pupil	Often (30–79%)
Involuntary, rapid, rhythmic eye movements	Often (30–79%)
Slow pupillary light response	Often (30–79%)
Tonic pupil	Often (30–79%)
Asymmetric pupil sizes	Sometimes (5–29%)

Abnormality of the ear

Trait	How often it is seen
Sensorineural hearing impairment	Always
Profound sensorineural hearing impairment	Sometimes (5–29%)
Ringing in ears	Sometimes (5–29%)
Hearing impairment	Not recorded

Abnormality of head or neck

Trait	How often it is seen
Tongue twitching	Always
Drooling	Often (30–79%)
Sleepy facial expression	Often (30–79%)

Abnormality of the respiratory system

Trait	How often it is seen
Cough	Sometimes (5–29%)
Respiratory function loss	Sometimes (5–29%)

Constitutional symptom

Trait	How often it is seen
Exercise-induced muscle pain	Sometimes (5–29%)
Shoulder pain	Sometimes (5–29%)

Laboratory abnormality

Trait	How often it is seen
Episodic fever	Often (30–79%)
Increased CSF protein concentration	Not recorded

Abnormality of the digestive system

Trait	How often it is seen
Impaired oropharyngeal swallow response	Often (30–79%)

Abnormality of the genitourinary system

Trait	How often it is seen
Urinary bladder sphincter dysfunction	Sometimes (5–29%)

Abnormality of the immune system

Trait	How often it is seen
Abnormality of the immune system	Not recorded

Abnormality of the voice

Trait	How often it is seen
Abnormality of the voice	Sometimes (5–29%)

How often is among people with one of the gene's conditions, the most often across them, as the Human Phenotype Ontology records it. These pages describe traits and the research behind them; they are not a diagnosis, and a doctor or genetic counsellor is the person to ask about symptoms.

Where this comes from

The Human Phenotype Ontology, release 2026-09-01: the traits linked to PMP22 and how often each is seen. Find out more at hpo.jax.org.

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