Traits

Traits linked to SPTLC2

serine palmitoyltransferase long chain base subunit 2

The Human Phenotype Ontology links 84 traits to SPTLC2, by body system: features seen in people with one of the gene's rare conditions.

Abnormality of the nervous system

Trait	How often it is seen
Decreased motor nerve conduction velocity	Always
Decreased sensation in extremities	Always
Impaired pain sensation	Always
Impaired vibration sensation in the lower limbs	Always
Nerve damage causing decreased feeling and movement	Always
Upper limb hyperreflexia	Always
Abnormality of balance	Very often (80–99%)
Abnormality of the autonomic nervous system	Very often (80–99%)
Decreased amplitude of sensory action potentials	Very often (80–99%)
Lou Gehrig's disease	Very often (80–99%)
Abnormal gait	Often (30–79%)
Abnormal speech pattern	Often (30–79%)
Arm dystonia	Often (30–79%)
Brisk reflexes	Often (30–79%)
Bulbar signs	Often (30–79%)
CNS hypomyelination	Often (30–79%)
Decreased touch sensation in extremities	Often (30–79%)
Delayed ability to walk	Often (30–79%)
Dystonia	Often (30–79%)
Hand tingling	Often (30–79%)
High stepping	Often (30–79%)
Impaired temperature sensation	Often (30–79%)
Inability to walk	Often (30–79%)
Pain insensitivity	Often (30–79%)
Trophic changes related to pain	Often (30–79%)
Abnormality of the cerebellum	Sometimes (5–29%)
Ataxia	Sometimes (5–29%)
Axial dystonia	Sometimes (5–29%)
Behavioral abnormality	Sometimes (5–29%)
Chorea	Sometimes (5–29%)
Clonus	Sometimes (5–29%)
Cognitive impairment	Sometimes (5–29%)
Distal sensory impairment of all modalities	Sometimes (5–29%)
Dysesthesia	Sometimes (5–29%)
Global developmental delay	Sometimes (5–29%)
Head titubation	Sometimes (5–29%)
Loss of articulate speech	Sometimes (5–29%)
Motor axonal neuropathy	Sometimes (5–29%)
Oromandibular dystonia	Sometimes (5–29%)
Parkinsonism	Sometimes (5–29%)
Toe walking	Sometimes (5–29%)

Abnormality of the musculoskeletal system

Trait	How often it is seen
Distal muscle wasting	Very often (80–99%)
Lower limb spasticity	Very often (80–99%)
Muscle degeneration	Very often (80–99%)
Muscle weakness	Very often (80–99%)
Uncontrollable movement in upper arms	Very often (80–99%)
Weakness of outermost muscles	Very often (80–99%)
Limb pain	Often (30–79%)
Lower-limb joint contracture	Often (30–79%)
Muscle fiber degeneration	Often (30–79%)
Spastic diplegia	Often (30–79%)
Spasticity and rigidity of muscles	Often (30–79%)
Upper-limb joint contracture	Often (30–79%)
EMG: slow motor conduction	Sometimes (5–29%)
Neck flexion weakness	Sometimes (5–29%)
Neuropathic arthropathy	Sometimes (5–29%)
Opisthotonus	Sometimes (5–29%)
Proximal neurogenic muscle weakness	Sometimes (5–29%)
Scoliosis	Sometimes (5–29%)
Spontaneous fracture	Sometimes (5–29%)

Abnormality of the integument

Trait	How often it is seen
Hyperkeratosis	Often (30–79%)
Lack of sweating or excessive sweating	Often (30–79%)
Open skin sore	Often (30–79%)
Penetrating foot ulcers	Often (30–79%)
Poor wound healing	Often (30–79%)
Lack of sweating	Sometimes (5–29%)

Abnormality of limbs

Trait	How often it is seen
Distal lower limb muscle weakness	Always
Distal upper limb muscle weakness	Always
Hyporeflexia of lower limbs	Always
Foot drop	Often (30–79%)
Autoamputation of digits	Sometimes (5–29%)

Abnormality of the digestive system

Trait	How often it is seen
Acid reflux	Sometimes (5–29%)
Gastrostomy tube feeding in infancy	Sometimes (5–29%)
Poor swallowing	Sometimes (5–29%)

Abnormality of head or neck

Trait	How often it is seen
Abnormally small head	Sometimes (5–29%)
Retrocollis	Sometimes (5–29%)

Abnormality of the eye

Trait	How often it is seen
Involuntary, rapid, rhythmic eye movements	Sometimes (5–29%)
Supranuclear gaze palsy	Sometimes (5–29%)

Abnormality of the ear

Trait	How often it is seen
Hearing impairment	Sometimes (5–29%)

Abnormality of the genitourinary system

Trait	How often it is seen
Loss of bladder control	Sometimes (5–29%)

Abnormality of the immune system

Trait	How often it is seen
Bone infection	Often (30–79%)

Abnormality of the respiratory system

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

Constitutional symptom

Trait	How often it is seen
Impaired ability to dress oneself	Very often (80–99%)

Growth abnormality

Trait	How often it is seen
Wasting syndrome	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 SPTLC2 and how often each is seen. Find out more at hpo.jax.org.

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