What are the other Names for this Condition? (Also known as/Synonyms)

• Jadassohn-Lewandowsky Syndrome
• Pachyonychia Congenita Type 1

What is Circumscribed Disseminated Keratosis, Jadassohn Lewandowsky type? (Definition/Background Information)

• Circumscribed Disseminated Keratosis, Jadassohn Lewandowsky type is a rare, predominantly inherited disorder, characterized by thickening of nails and skin 
• The exact prevalence of the disease is not known. Both genders may be affected without ethnic or racial bias
• Mutations(s) in KRT6A and KRT16 genes are known to cause Circumscribed Disseminated Keratosis, Jadassohn Lewandowsky type. These genes code for forms of keratin protein
• Treatment methods are geared toward removing hardened skin and nails, for which mechanical, chemical, or surgical methods may be employed
• The prognosis of Circumscribed Disseminated Keratosis, Jadassohn Lewandowsky type depends on the severity of symptoms, and whether rare complications such as respiratory distress and bone loss occur

Who gets Circumscribed Disseminated Keratosis, Jadassohn Lewandowsky type? (Age and Sex Distribution)

• Circumscribed Disseminated Keratosis, Jadassohn Lewandowsky type is a rare congenital disorder; the exact prevalence is not known
• The manifestation of symptoms typically occurs in childhood, and can be as early as in the neonatal or infancy stage
• Both males and females may be affected
• Worldwide, individuals of all racial and ethnic groups may be affected

What are the Risk Factors for Circumscribed Disseminated Keratosis, Jadassohn Lewandowsky type? (Predisposing Factors)

• A positive family history may be an important risk factor, since Circumscribed Disseminated Keratosis, Jadassohn Lewandowsky type may be inherited
• Currently, no risk factors have been clearly identified for this disorder for cases that occur sporadically

It is important to note that having a risk factor does not mean that one will get the condition. A risk factor increases one’s chances of getting a condition compared to an individual without the risk factors. Some risk factors are more important than others.

Also, not having a risk factor does not mean that an individual will not get the condition. It is always important to discuss the effect of risk factors with your healthcare provider.

What are the Causes of Circumscribed Disseminated Keratosis, Jadassohn Lewandowsky type? (Etiology)

• Circumscribed Disseminated Keratosis, Jadassohn Lewandowsky type may either arise sporadically, or caused by mutation(s) in either KRT6A or KRY16 genes
• These genes code for types of keratin protein
• When inherited, Circumscribed Disseminated Keratosis, Jadassohn Lewandowsky type is passed from parents to children in an autosomal dominant pattern

Autosomal dominant: Autosomal dominant conditions are traits or disorders that are present when only one copy of the mutation is inherited on a non-sex chromosome. In these types of conditions, the individual has one normal copy and one mutant copy of the gene. The abnormal gene dominates, masking the effects of the correctly function gene. If an individual has an autosomal dominant condition, the chance of passing the abnormal gene on to their offspring is 50%. Children, who do not inherit the abnormal gene, will not develop the condition or pass it on to their offspring

What are the Signs and Symptoms of Circumscribed Disseminated Keratosis, Jadassohn Lewandowsky type?

The signs and symptoms of Circumscribed Disseminated Keratosis, Jadassohn Lewandowsky type may vary among affected individuals. It has been reported that individuals with KRT6A mutations exhibit more severe symptoms than those with KRT16 gene mutation(s).

The following are some known signs and symptoms of Circumscribed Disseminated Keratosis, Jadassohn Lewandowsky type:

• Thickened fingernails and toenails
• Discolored nails (yellow or gray)
• Thick nails that are hard to cut
• Curved nails appearing like claws
• Thickened skin in palms and soles
• Calluses in palms and soles 
• Bony projections on skin
• White patches in the mucous lining of the mouth (oral leukokeratosis)
• White patches in the lining of larynx (laryngeal leukokeratosis)
• Acroosteolysis or bone resorption

How is Circumscribed Disseminated Keratosis, Jadassohn Lewandowsky type Diagnosed?

Circumscribed Disseminated Keratosis, Jadassohn Lewandowsky type is diagnosed on the basis of the following information:

• Complete physical examination
• Thorough medical history evaluation
• Assessment of signs and symptoms
• Laboratory tests
• Imaging studies
• Biopsy studies, if necessary

Many clinical conditions may have similar signs and symptoms. Your healthcare provider may perform additional tests to rule out other clinical conditions to arrive at a definitive diagnosis.

What are the possible Complications of Circumscribed Disseminated Keratosis, Jadassohn Lewandowsky type?

The complications of Circumscribed Disseminated Keratosis, Jadassohn Lewandowsky type may include:

• Respiratory distress
• Weakening of bones due to bone resorption

Complications may occur with or without treatment, and in some cases, due to treatment also.

How is Circumscribed Disseminated Keratosis, Jadassohn Lewandowsky type Treated?

The treatment for Circumscribed Disseminated Keratosis, Jadassohn Lewandowsky type may include:

• Mechanical abrasion of affected skin to reduce hyperkeratosis
• Use of chemicals, such as urea and propylene glycol, to reduce keratinization of skin
• Use of vitamin A for hyperkeratosis
• Surgical excision of bony projections
• Surgical removal of abnormal nails

How can Circumscribed Disseminated Keratosis, Jadassohn Lewandowsky type be Prevented?

Currently, Circumscribed Disseminated Keratosis, Jadassohn Lewandowsky type may not be preventable, since it is reportedly an inherited disorder.

• Genetic testing of the expecting parents (and related family members) and prenatal diagnosis (molecular testing of the fetus during pregnancy) may help in understanding the risks better during pregnancy
• If there is a family history of the condition, then genetic counseling will help assess risks, before planning for a child
• Active research is currently being performed to explore the possibilities for treatment and prevention of inherited and acquired genetic disorders

Regular medical screening at periodic intervals with tests and physical examinations are recommended.

What is the Prognosis of Circumscribed Disseminated Keratosis, Jadassohn Lewandowsky type? (Outcomes/Resolutions)

• The prognosis of Circumscribed Disseminated Keratosis, Jadassohn Lewandowsky type is dependent upon the severity of the signs and symptoms and associated complications, if any
• Individuals with mild conditions have better prognosis than those with severe symptoms and complications
• Typically, the prognosis may be assessed on a case-by-case basis

Additional and Relevant Useful Information for Circumscribed Disseminated Keratosis, Jadassohn Lewandowsky type:

The following DoveMed website link is a useful resource for additional information:

http://www.dovemed.com/diseases-conditions/rare-disorders/