Keratoderma with woolly hair

What it is, symptoms and effects

From: MedlinePlus Genetics, National Library of Medicine

Keratoderma with woolly hair is a group of related conditions that affect the skin and hair and in many cases increase the risk of potentially life-threatening heart problems. People with these conditions have hair that is unusually coarse, dry, fine, and tightly curled. In some cases, the hair is also sparse. The woolly hair texture typically affects only scalp hair and is present from birth. Starting early in life, affected individuals also develop palmoplantar keratoderma, a condition that causes skin on the palms of the hands and the soles of the feet to become thick, scaly, and calloused.

Cardiomyopathy, which is a disease of the heart muscle, is a life-threatening health problem that can develop in people with keratoderma with woolly hair. Unlike the other features of this condition, signs and symptoms of cardiomyopathy may not appear until adolescence or later. Complications of cardiomyopathy can include an abnormal heartbeat (arrhythmia), heart failure, and sudden death.

Keratoderma with woolly hair comprises several related conditions with overlapping signs and symptoms. Researchers have recently proposed classifying keratoderma with woolly hair into four types, based on the underlying genetic cause. Type I, also known as Naxos disease, is characterized by palmoplantar keratoderma, woolly hair, and a form of cardiomyopathy called arrhythmogenic right ventricular cardiomyopathy (ARVC). Type II, also known as Carvajal syndrome, has hair and skin abnormalities similar to type I but features a different form of cardiomyopathy, called dilated left ventricular cardiomyopathy. Type III also has signs and symptoms similar to those of type I, including ARVC, although the hair and skin abnormalities are often milder. Type IV is characterized by palmoplantar keratoderma and woolly and sparse hair, as well as abnormal fingernails and toenails. Type IV does not appear to cause cardiomyopathy.

Causes and biological mechanisms

From: MedlinePlus Genetics, National Library of Medicine

Mutations in the JUP, DSP, DSC2, and KANK2 genes cause keratoderma with woolly hair types I through IV, respectively. The JUP, DSP, and DSC2 genes provide instructions for making components of specialized cell structures called desmosomes. Desmosomes are located in the membrane surrounding certain cells, including skin and heart muscle cells. Desmosomes help attach cells to one another, which provides strength and stability to tissues. They also play a role in signaling between cells.

Mutations in the JUP, DSP, or DSC2 gene alter the structure and impair the function of desmosomes. Abnormal or missing desmosomes prevent cells from sticking to one another effectively, which likely makes the hair, skin, and heart muscle more fragile. Over time, as these tissues are exposed to mechanical stress (for example, friction on the surface of the skin or the constant contraction and relaxation of the heart muscle), they become damaged and can no longer function normally. This mechanism probably underlies the skin, hair, and heart problems that occur in keratoderma with woolly hair. Some studies suggest that abnormal cell signaling may also contribute to cardiomyopathy in people with this group of conditions.

Unlike the other genes associated with keratoderma with woolly hair, the KANK2 gene provides instructions for making a protein that is not part of desmosomes. Instead, it regulates other proteins called steroid receptor coactivators (SRCs), whose function is to help turn on (activate) certain genes. SRCs play important roles in tissues throughout the body, including the skin. Studies suggest that mutations in the KANK2 gene disrupt the regulation of SRCs, which leads to abnormal gene activity. However, it is unclear how these changes underlie the skin and hair abnormalities in keratoderma with woolly hair type IV.

Inheritance and family implications

From: MedlinePlus Genetics, National Library of Medicine

Most cases of keratoderma with woolly hair have an autosomal recessive pattern of inheritance, which means both copies of the gene in each cell have mutations. The parents of an individual with an autosomal recessive condition each carry one copy of the mutated gene, but they usually do not show signs and symptoms of the condition.

How common is it?

From: MedlinePlus Genetics, National Library of Medicine

Keratoderma with woolly hair is rare; its prevalence worldwide is unknown.

Type I (Naxos disease) was first described in families from the Greek island of Naxos. Since then, affected families have been found in other Greek islands, Turkey, and the Middle East. This form of the condition may affect up to 1 in 1,000 people from the Greek islands.

Type II (Carvajal syndrome), type III, and type IV have each been identified in only a small number of families worldwide.

Which doctor should you see?

The suggested department for discussing Keratoderma with woolly hair 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 Keratoderma with woolly hair. 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.