Arts syndrome

What it is, symptoms and effects

From: MedlinePlus Genetics, National Library of Medicine

Arts syndrome is a disorder that causes serious neurological problems in males. Females can also be affected by this condition, but they typically have much milder symptoms.

Boys with Arts syndrome have profound sensorineural hearing loss, which is a complete or almost complete loss of hearing caused by abnormalities in the inner ear. Other features of the disorder include weak muscle tone (hypotonia), impaired muscle coordination (ataxia), developmental delay, and intellectual disability. In early childhood, affected boys develop vision loss caused by degeneration of nerves that carry information from the eyes to the brain (optic nerve atrophy). They also experience loss of sensation and weakness in the limbs (peripheral neuropathy).

Boys with Arts syndrome also usually have recurrent infections, especially involving the respiratory system. Because of these infections and their complications, affected boys often do not survive past early childhood.

In females with Arts syndrome, hearing loss that begins in adulthood may be the only symptom.

Causes and biological mechanisms

From: MedlinePlus Genetics, National Library of Medicine

Mutations in the PRPS1 gene cause Arts syndrome. The PRPS1 gene provides instructions for making an enzyme called phosphoribosyl pyrophosphate synthetase 1, or PRPP synthetase 1. This enzyme is involved in producing purines and pyrimidines, which are building blocks of DNA, its chemical cousin RNA, and molecules such as ATP and GTP that serve as energy sources in the cell.

The PRPS1 gene mutations that cause Arts syndrome replace single protein building blocks (amino acids) in the PRPP synthetase 1 enzyme. The resulting enzyme is probably unstable, reducing or eliminating its ability to perform its function. The disruption of purine and pyrimidine production may impair energy storage and transport in cells. Impairment of these processes may have a particularly severe effect on tissues that require a large amount of energy, such as the nervous system, resulting in the neurological problems characteristic of Arts syndrome. The reason for the increased risk of respiratory infections in Arts syndrome is unclear.

Inheritance and family implications

From: MedlinePlus Genetics, National Library of Medicine

This condition is inherited in an X-linked pattern. The gene associated with this condition is located on the X chromosome, which is one of the two sex chromosomes. In males (who have only one X chromosome), a mutation in the only copy of the gene in each cell causes the disorder. In females (who have two X chromosomes), a mutation in one of the two copies of the gene in each cell sometimes causes features of the disorder; in other cases, these females do not experience any symptoms.

In the small number of Arts syndrome cases that have been identified, affected individuals have inherited the mutation from a mother who carries an altered copy of the PRPS1 gene.

How common is it?

From: MedlinePlus Genetics, National Library of Medicine

Arts syndrome appears to be extremely rare. Only a few families with this disorder have been described in the medical literature.

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.

Abnormal erythrocyte enzyme activity · Very frequent (99-80%)

An altered level of any enzyme to act as catalysts within erythrocytes. This term includes changes due to altered activity of an enzyme.

Abnormality of somatosensory evoked potentials · Very frequent (99-80%)

An abnormality of somatosensory evoked potentials (SSEP), i.e., of the electrical signals of sensation going from the body to the brain in response to a defined stimulus. Recording electrodes are placed over the scalp, spine, and peripheral nerves proximal to the stimulation site. Clinical studies generally use electrical stimulation of peripheral nerves to elicit potentials. SSEP testing determines whether peripheral sensory nerves are able to transmit sensory information like pain, temperature, and touch to the brain. Abnormal SSEPs can result from dysfunction at the level of the peripheral nerve, plexus, spinal root, spinal cord, brain stem, thalamocortical projections, or primary somatosensory cortex.

Blindness · Very frequent (99-80%)

Blindness is the condition of lacking visual perception defined as a profound reduction in visual perception. On the 6m visual acuity scale, blindness is defined as less than 3/60. On the 20ft visual acuity scale, blindness is defined as less than 20/400. On the decimal visual acuity scale, blindness is defined as less than 0.05. Blindness is typically characterized by a visual field of no greater than 10 degrees in radius around central fixation.

Congenital sensorineural hearing impairment · Very frequent (99-80%)

A type of hearing impairment caused by an abnormal functionality of the cochlear nerve with congenital onset.

Decreased motor nerve conduction velocity · Very frequent (99-80%)

A type of decreased nerve conduction velocity that affects the motor neuron.

EMG: chronic denervation signs · Very frequent (99-80%)

Evidence of chronic denervation on electromyography.

Muscle weakness · Very frequent (99-80%)

Reduced strength of muscles.

Mutism · Very frequent (99-80%)

Complete lack of speech or verbal communication in a person despite attempts to engage in conversation. Mutism as a phenomena assumes the individual has previous capacity for speech and in the pediatric population it assumes that the person is past the age of typical language development.

Other findings in the same source

From: Orphanet

Additional reported features include Optic atrophy (Very frequent (99-80%)); Recurrent infections (Very frequent (99-80%)); Recurrent upper respiratory tract infections (Very frequent (99-80%)); Severe demyelination of the white matter (Very frequent (99-80%)); Severe infection (Very frequent (99-80%)); Visual impairment (Very frequent (99-80%)); Appendicular hypotonia (Frequent (79-30%)); Areflexia (Frequent (79-30%)); Ataxia (Frequent (79-30%)); Axial hypotonia (Frequent (79-30%)). This is a selected summary, not a complete description of the condition.

Which doctor should you see?

The suggested department for discussing Arts syndrome is Clinical Genetics, with a clinical geneticist as the relevant type of clinician. Paediatrician (children) or physician (adults), with clinical geneticist referral.

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.

• Does the exact genetic or chromosome finding explain the observed features?
• Would a genetic counsellor help the family understand the result?
• Which organ-specific assessments are appropriate for this particular diagnosis?

Treatment discussions and follow-up

The material gathered for this draft does not provide a complete condition-specific treatment pathway for Arts syndrome. 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.