Spastic paraplegia type 7

What it is, symptoms and effects

From: MedlinePlus Genetics, National Library of Medicine

Spastic paraplegia type 7 (also called SPG7) is one of more than 80 genetic disorders known as hereditary spastic paraplegias. These disorders primarily affect the brain and spinal cord (central nervous system),specifically nerve cells (neurons) that extend down the spinal cord. These neurons are used for muscle movement and sensation.Signs and symptoms of hereditary spastic paraplegias are characterized by progressive muscle stiffness (spasticity) in the legs and difficulty walking.

Hereditary spastic paraplegias are divided into two types: pure and complex. The pure types generally involve only spasticity of the lower limbs and walking difficulties. The complex types involve more widespread problems with the nervous system; the structure or functioning of the brain; and the nerves connecting the brain and spinal cord to muscles and sensory cells that detect sensations such as touch, pain, heat, and sound (the peripheral nervous system). In complex forms, there can also be features outside of the nervous system. Spastic paraplegia type 7 can occur in either the pure or complex form.

Like all hereditary spastic paraplegias, spastic paraplegia type 7 involves spasticity of the leg muscles and some muscle weakness. People with this form of spastic paraplegia can also have ataxia; a pattern of movement abnormalities known as parkinsonism; exaggerated reflexes (hyperreflexia) in the arms; speech difficulties (dysarthria); difficulty swallowing (dysphagia); involuntary movements of the eyes (nystagmus); mild hearing loss; abnormal curvature of the spine (scoliosis); high-arched feet (pes cavus); numbness, tingling, or pain in the arms and legs (sensory neuropathy); disturbance in the nerves used for muscle movement (motor neuropathy); and muscle wasting (amyotrophy). The onset of symptoms varies greatly among those with spastic paraplegia type 7; however, abnormalities in muscle tone and other features usually become noticeable in adulthood.

ORPHANET DEFINITION A form of hereditary spastic ataxia characterized by an onset usually in adulthood (but ranging from 10-72 years) of progressive bilateral lower limb weakness and spasticity and sometimes predominant cerebellar ataxia. In addition to frequent sphincter dysfunction and decreased vibratory sense at the ankles, manifestations may include optical neuropathy, nystagmus, blepharoptosis, ophthalmoplegia, decreased hearing, scoliosis, pes cavus, motor and sensory neuropathy, muscle atrophy, parkinsonism, and dystonia.

Inheritance

From: MedlinePlus Genetics, National Library of Medicine

Autosomal recessive

Frequency in the source

From: MedlinePlus Genetics, National Library of Medicine

Point prevalence: Unknown; Worldwide; Class only.

Reported clinical features and what the terms mean

The following findings are associated with this condition in Orphanet. They are not a checklist for diagnosing yourself, and they do not all occur in every affected person. Some are examination, imaging or laboratory findings that cannot be recognised at home.

The frequency labels describe how often a finding was reported among people with the condition in the source. They do not give the chance that a person with that symptom has the condition. Definitions below reproduce HPO terminology; they explain the term, not the likely severity in an individual.

Spastic gait · Very frequent (99-80%)

Spasticity is manifested by increased stretch reflex which is intensified with movement velocity. This results in excessive and inappropriate muscle activation which can contribute to muscle hypertonia. Spastic gait is characterized by manifestations such as muscle hypertonia, stiff knee, and circumduction of the leg.

Abnormal mitochondrial morphology · Frequent (79-30%)

Any structural anomaly of the mitochondria.

Abnormal pyramidal sign · Frequent (79-30%)

Functional neurological abnormalities related to dysfunction of the pyramidal tract.

Abnormality of higher mental function · Frequent (79-30%)

Cognitive, psychiatric, or memory anomaly.

Attention deficit hyperactivity disorder · Frequent (79-30%)

Attention deficit hyperactivity disorder (ADHD) manifests at age 2-3 years or by first grade at the latest. The main symptoms are distractibility, impulsivity, hyperactivity, and often trouble organizing tasks and projects, difficulty going to sleep, and social problems from being aggressive, loud, or impatient.

Babinski sign · Frequent (79-30%)

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.

Cerebellar atrophy · Frequent (79-30%)

Cerebellar atrophy is defined as a cerebellum with initially normal structures, in a posterior fossa with normal size, which displays enlarged fissures (interfolial spaces) in comparison to the foliae secondary to loss of tissue. Cerebellar atrophy implies irreversible loss of tissue and result from an ongoing progressive disease until a final stage is reached or a single injury, e.g. an intoxication or infectious event.

Hypernasal speech · Frequent (79-30%)

A type of speech characterized by the presence of an abnormally increased nasal airflow during speech associated with structural abnormality of the nasal passages.

Impaired vibration sensation in the lower limbs · Frequent (79-30%)

A decrease in the ability to perceive vibration in the legs.

Lower limb hyperreflexia · Frequent (79-30%)

Increased intensity of the a reflex in the leg.

Lower limb muscle weakness · Frequent (79-30%)

Weakness of the muscles of the legs.

Nystagmus · Frequent (79-30%)

Rhythmic, involuntary oscillations of one or both eyes related to abnormality in fixation, conjugate gaze, or vestibular mechanisms.

Optic atrophy · Frequent (79-30%)

Atrophy of the optic nerve. Optic atrophy results from the death of the retinal ganglion cell axons that comprise the optic nerve and manifesting as a pale optic nerve on fundoscopy.

Ragged-red muscle fibers · Frequent (79-30%)

An abnormal appearance of muscle fibers observed on muscle biopsy. Ragged red fibers can be visualized with Gomori trichrome staining as irregular and intensely red subsarcolemmal zones, whereas the normal myofibrils are green. The margins of affect fibers appear red and ragged. The ragged-red is due to the accumulation of abnormal mitochondria below the plasma membrane of the muscle fiber, leading to the appearance of a red rim and speckled sarcoplasm.

Other findings in the same source

From: Orphanet

Additional reported features include Somatic sensory dysfunction (Frequent (79-30%)); Supranuclear gaze palsy (Frequent (79-30%)); Urinary urgency (Frequent (79-30%)); Lower limb hypertonia (Frequent (79-30%)); Slowed slurred speech (Frequent (79-30%)); Abnormal cerebral white matter morphology (Occasional (29-5%)); Cerebral cortical atrophy (Occasional (29-5%)); Dysarthria (Occasional (29-5%)); Optic disc pallor (Occasional (29-5%)); Pes cavus (Occasional (29-5%)). This is a selected summary, not a complete description of the condition.

When it may begin

From: MedlinePlus Genetics, National Library of Medicine

Adolescent; Adult; Childhood; Elderly

Inheritance in the source

From: MedlinePlus Genetics, National Library of Medicine

Autosomal recessive

Frequency and the population described

From: MedlinePlus Genetics, National Library of Medicine

Point prevalence: Unknown; Worldwide; Class only.

Understanding the inheritance label

From: MedlinePlus Genetics

An autosomal recessive pattern usually involves disease-causing changes in both copies of a gene. Parents may each carry one altered copy without having the condition themselves. A genetic counsellor can explain carrier testing and reproductive implications using the actual laboratory findings, rather than the condition name alone.

Which doctor should you see?

The suggested department for discussing Spastic paraplegia type 7 is Neurology, with a neurologist as the relevant type of clinician. General physician / Family Medicine; paediatrician for children. Referral depends on symptoms.

Additional services that may be relevant, depending on the findings, include: Clinical Genetics.

This is an editorial referral starting point. The appropriate clinic depends on the person’s age, symptoms, previous diagnosis and local services. The first clinician can decide whether another specialty or a team is needed; a department label does not confirm the diagnosis.

How to prepare for an assessment

Bring a short timeline of the main symptoms: when they first appeared, whether they are constant or episodic, what seems to change them, and how they affect daily activities. Include previous reports, discharge summaries, current medicines and supplements, allergies, and any relevant family history. A dated record is more useful than trying to match every feature in an online article.

Ask the clinician what is already established and what remains uncertain. If a test is suggested, ask what question it answers, what its limitations are and how the result would change the next step. The information here is not an instruction to arrange every possible test. In children, bring growth, developmental and school information if it is relevant to the concern.

• Which nervous-system findings help explain the symptoms?
• Would an assessment of walking, communication or daily function be helpful?
• Are rehabilitation or other specialist services relevant?

Treatment discussions and follow-up

The material gathered for this draft does not provide a complete condition-specific treatment pathway for Spastic paraplegia type 7. That gap does not mean that treatment is unavailable. A clinician needs to establish the diagnosis and review current guidance before recommending medicines, procedures, rehabilitation or other support.

Before leaving the appointment, clarify the next review date, who will communicate results, and whom to contact if the situation changes. Discuss difficulties with sleep, work, school, mobility, eating or emotional wellbeing when these are relevant. Practical support may require coordination between the treating clinician and other services.

The collected references do not establish a complete prevention or long-term outlook section for this entry. Missing information should not be interpreted as proof that prevention is impossible or that a particular outcome is inevitable. Ask what is known for the exact subtype, stage and personal circumstances, and which uncertainties remain.

When to seek emergency help

Severe breathing difficulty, collapse, new stroke-like symptoms, a seizure that is prolonged or repeated without recovery, uncontrolled major bleeding, or an immediate risk of self-harm require emergency help. In India, call 112 or reach the nearest emergency department. This is a general, non-exhaustive warning list; it is not a condition-specific triage tool.