Bart-Pumphrey syndrome

What it is, symptoms and effects

From: MedlinePlus Genetics, National Library of Medicine

Bart-Pumphrey syndrome is characterized by nail and skin abnormalities and hearing loss.

People with Bart-Pumphrey syndrome typically have a white discoloration of the nails (leukonychia); the nails may also be thick and crumbly. Affected individuals often have wart-like (verrucous) skin growths called knuckle pads on the knuckles of the fingers and toes. They may also have thickening of the skin on the palms of the hands and soles of the feet (palmoplantar keratoderma). The skin abnormalities generally become noticeable during childhood.

The hearing loss associated with Bart-Pumphrey syndrome ranges from moderate to profound and is typically present from birth (congenital).

The signs and symptoms of this disorder may vary even within the same family; while almost all affected individuals have hearing loss, they may have different combinations of the other associated features.

Causes and biological mechanisms

From: MedlinePlus Genetics, National Library of Medicine

Bart-Pumphrey syndrome is caused by mutations in the GJB2 gene. This gene provides instructions for making a protein called gap junction beta 2, more commonly known as connexin 26. Connexin 26 is a member of the connexin protein family. Connexin proteins form channels called gap junctions that permit the transport of nutrients, charged atoms (ions), and signaling molecules between neighboring cells that are in contact with each other. Gap junctions made with connexin 26 transport potassium ions and certain small molecules.

Connexin 26 is found in cells throughout the body, including the inner ear and the skin. In the inner ear, channels made from connexin 26 are found in a snail-shaped structure called the cochlea. These channels may help to maintain the proper level of potassium ions required for the conversion of sound waves to electrical nerve impulses. This conversion is essential for normal hearing. In addition, connexin 26 may be involved in the maturation of certain cells in the cochlea. Connexin 26 also plays a role in the growth, maturation, and stability of the outermost layer of skin (the epidermis).

The GJB2 gene mutations that cause Bart-Pumphrey syndrome change single protein building blocks (amino acids) in the connexin 26 protein. The altered protein probably disrupts the function of normal connexin 26 in cells, and may interfere with the function of other connexin proteins. This disruption could affect skin growth and also impair hearing by disturbing the conversion of sound waves to nerve impulses.

Inheritance and family implications

From: MedlinePlus Genetics, National Library of Medicine

This condition is inherited in an autosomal dominant pattern, which means one copy of the altered gene in each cell is sufficient to cause the disorder. In most cases, an affected person has one parent with the condition. Other cases result from new mutations in the gene and occur in people with no history of the disorder in their family.

How common is it?

From: MedlinePlus Genetics, National Library of Medicine

Bart-Pumphrey syndrome is a rare disorder; its exact prevalence is unknown. Only a few affected families and individual cases have been identified.

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.

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.

Knuckle pad · Very frequent (99-80%)

Knuckle pads are benign fibrofatty subcutaneous pads located over the proximal interphalangeal (PIP) joints that can be mistaken for arthritis. Rarely they affect the dorsal aspect of the metacarpophalangeal (MCP) joints. Clinically they are painless and often affect both hands in an asymmetrical pattern.

Leukonychia · Very frequent (99-80%)

White discoloration of the nails.

Palmoplantar hyperkeratosis · Frequent (79-30%)

Abnormal thickening of the skin localized to the palm of the hand and the sole of the foot.

Palmoplantar keratoderma · Frequent (79-30%)

Abnormal thickening of the skin of the palms of the hands and the soles of the feet.

Hyperkeratotic papule · Occasional (29-5%)

A circumscribed, solid elevation of skin with no visible fluid, varying in size from a pinhead to less than 10mm in diameter at the widest point that is composed of localized hyperkeratosis (the latter may be demonstrated histopathologically).

Mixed hearing impairment · Occasional (29-5%)

A type of hearing loss resulting from a combination of conductive hearing impairment and sensorineural hearing impairment.

Which doctor should you see?

The suggested department for discussing Bart-Pumphrey syndrome is Dermatology, with a dermatologist as the relevant type of clinician. Dermatologist; paediatric services for children as appropriate.

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 features of the skin, hair or nails distinguish the possibilities?
• Would photographs over time help document the changes?
• What should be expected from treatment, and how will irritation or other adverse effects be managed?

Treatment discussions and follow-up

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