National Center for Advancing and Translational Sciences Genetic and Rare Diseases Information Center, a program of the National Center for Advancing and Translational Sciences

Pachyonychia congenita


Other Names:
Congenital pachyonychia; Pachyonychia congenita syndrome
Categories:
This disease is grouped under:
Pachyonychia congenita (PC) is a rare inherited condition that primarily affects the nails and skin. The fingernails and toenails may be thickened and abnormally shaped. Affected people can also develop painful calluses and blisters on the soles of their feet and less frequently on the palms of their hands (palmoplantar keratoderma). Additional features include white patches on the tongue and inside of the mouth (leukokeratosis); bumps around the elbows, knees, and waistline (follicular hyperkeratosis); and cysts of various types including steatocystoma. Features may vary among affected people depending on their specific mutation.[1][2] PC is divided into 5 types based on the specific keratin gene involved: PC-K6a, PC-K6b, PC-K6c, PC-K16, and PC-K17. All forms are inherited in an autosomal dominant manner.[2][3] Treatment is based on the signs and symptoms present in each person.[2]
Last updated: 12/10/2015
The signs and symptoms of pachyonychia congenita (PC) vary based on the specific keratin gene involved (KRT6A, KRT6B, KRT6C, KRT16, and KRT17) and the specific gene mutation. However, the most common features of the condition include:[3][2]
  • Thickened nails
  • Plantar hyperkeratosis (thickened skin on the soles of the feet) with underlying blisters
  • Plantar pain
  • Various types of cysts (i.e. steatocystoma and pilosebaceous cysts - two types of sebaceous gland cysts)
  • Follicular hyperkeratosis (small bumps at the base of hairs)
  • Leukokeratosis (white patches on the tongue, in the mouth, or on the inside of the cheek)
Some affected people may also develop calluses on the palms of the hands (palmar hyperkeratosis), sores at the corner of the mouth; natal teeth; a hoarse cry or voice caused by white film on the larynx (voice box); and/or intense pain when beginning to eat or swallow.[3][2]

For more specific information on the signs and symptoms of PC, including specific features that are not associated with the condition, please visit the Pachyonychia Congenita Project's website.
Last updated: 12/11/2015

This table lists symptoms that people with this disease may have. For most diseases, symptoms will vary from person to person. People with the same disease may not have all the symptoms listed. This information comes from a database called the Human Phenotype Ontology (HPO) . The HPO collects information on symptoms that have been described in medical resources. The HPO is updated regularly. Use the HPO ID to access more in-depth information about a symptom.

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Medical Terms Other Names
Learn More:
HPO ID
80%-99% of people have these symptoms
Abnormality of nail color
Abnormality of nail colour
0100643
Hyperhidrosis
Excessive sweating
Increased sweating
Profuse sweating
Sweating
Sweating profusely
Sweating, increased
[ more ] 		0000975
Onychogryposis
Thick nail
Thickened nails
[ more ] 		0001805
30%-79% of people have these symptoms
Abnormal blistering of the skin
Blistering, generalized
Blisters
[ more ] 		0008066
Carious teeth
Dental cavities
Tooth cavities
Tooth decay
[ more ] 		0000670
Ichthyosis 0008064
Skin plaque 0200035
5%-29% of people have these symptoms
Abnormal fingernail morphology
Abnormal fingernails
Abnormality of the fingernails
[ more ] 		0001231
Alopecia
Hair loss
0001596
Anonychia
Absent nails
Aplastic nails
[ more ] 		0001798
Cataract
Clouding of the lens of the eye
Cloudy lens
[ more ] 		0000518
Cognitive impairment
Abnormality of cognition
Cognitive abnormality
Cognitive defects
Cognitive deficits
Intellectual impairment
Mental impairment
[ more ] 		0100543
Corneal dystrophy 0001131
Hepatomegaly
Enlarged liver
0002240
Laryngomalacia
Softening of voice box tissue
0001601
Respiratory insufficiency
Respiratory impairment
0002093
Percent of people who have these symptoms is not available through HPO
Autosomal dominant inheritance 0000006
Chapped lip
Chapped lips
Dry lips
[ more ] 		0040181
Dry hair 0011359
Epidermoid cyst
Skin cyst
0200040
Follicular hyperkeratosis 0007502
Folliculitis 0025084
Furrowed tongue
Grooved tongue
0000221
Gingivitis
Inflamed gums
Red and swollen gums
[ more ] 		0000230
Hoarse voice
Hoarseness
Husky voice
[ more ] 		0001609
Nail dysplasia
Atypical nail growth
0002164
Nail dystrophy
Poor nail formation
0008404
Natal tooth
Born with teeth
Teeth present at birth
[ more ] 		0000695
Onychogryposis of toenails
Overgrowth and curving of toenails
0008401
Oral leukoplakia
Oral white patch
0002745
Palmar hyperkeratosis 0010765
Palmoplantar hyperhidrosis
Excessive sweating of palms and soles
0007410
Palmoplantar hyperkeratosis
Thickening of the outer layer of the skin of the palms and soles
0000972
Palmoplantar keratoderma
Thickening of palms and soles
0000982
Plantar hyperkeratosis 0007556
Sparse and thin eyebrow
Thin, sparse eyebrows
0000535
Sparse scalp hair
Reduced/lack of hair on scalp
Scalp hair, thinning
Sparse, thin scalp hair
sparse-absent scalp hair
[ more ] 		0002209
Steatocystoma multiplex 0012035
Subungual hyperkeratosis
Thickened, discolored skin under nail
0008392
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Last updated: 7/1/2020
Pachyonychia congenita (PC) is caused by changes (mutations) in one of five genes: KRT6A, KRT6B, KRT6C, KRT16, and KRT17. These genes provide instructions for making a protein called keratin, which is found in the skin, hair, and nails. Mutations in any of these genes alter the structure of keratin proteins which interferes with their ability to provide strength and resilience to various parts of the body. This leads to the many signs and symptoms associated with pachyonychia congenita.[1]

PC is divided into 5 types based on the specific keratin gene involved: PC-K6a, PC-K6b, PC-K6c, PC-K16, and PC-K17.[3]
Last updated: 12/10/2015
Pachyonychia congenita (PC) is inherited in an autosomal dominant manner.[3][1] This means that to be affected, a person only needs a change (mutation) in one copy of the responsible gene in each cell. In some cases, an affected person inherits the mutation from an affected parent. Other cases may result from new (de novo) mutations in the gene. These cases occur in people with no history of the disorder in their family. A person with PC has a 50% chance with each pregnancy of passing along the altered gene to his or her child.
Last updated: 12/10/2015
A diagnosis of pachyonychia congenita (PC) is often suspected based on the presence of characteristic signs and symptoms. In fact, one study found that approximately 97% of people with genetically confirmed PC have toenail thickening, plantar keratoderma (thickening of the skin on the soles of the feet) and plantar pain by age ten.[2][3]

Identification of a change (mutation) in one of the five genes associated with PC confirms the diagnosis. [2][4]

Last updated: 12/10/2015

Testing Resources

  • The Genetic Testing Registry (GTR) provides information about the genetic tests for this condition. The intended audience for the GTR is health care providers and researchers. Patients and consumers with specific questions about a genetic test should contact a health care provider or a genetics professional.
  • Orphanet lists international laboratories offering diagnostic testing for this condition.
Current management of pachyonychia congenita is focused on relief of pain and other symptoms; hygienic grooming practices (such as trimming the nails and calluses); and treatment of infections when necessary. Some people may also require aids to help with mobility, such as wheelchairs, crutches and/or canes.[2][5]

Pachyonychia Congenita Project offers more detailed information regarding the treatment and management of PC. Please click on the link to access this resource.
Last updated: 12/10/2015
The long-term outlook (prognosis) for people with pachyonychia congenita (PC) varies. Although the condition is not associated with a reduced lifespan, it can negatively impact quality of life. Almost all people report constant pain caused by plantar keratosis (thickened skin on the soles of the feet) with underlying blisters and/or various types of cysts (i.e. steatocystoma and pilosebaceous cysts - two types of sebaceous gland cysts). This pain can interfere with mobility and day-to-day activities.[3][6]

For more information on living with PC, please visit the Pachyonychia Congenita Project's website.
Last updated: 12/11/2015

If you need medical advice, you can look for doctors or other healthcare professionals who have experience with this disease. You may find these specialists through advocacy organizations, clinical trials, or articles published in medical journals. You may also want to contact a university or tertiary medical center in your area, because these centers tend to see more complex cases and have the latest technology and treatments.

If you can’t find a specialist in your local area, try contacting national or international specialists. They may be able to refer you to someone they know through conferences or research efforts. Some specialists may be willing to consult with you or your local doctors over the phone or by email if you can't travel to them for care.

You can find more tips in our guide, How to Find a Disease Specialist. We also encourage you to explore the rest of this page to find resources that can help you find specialists.

Healthcare Resources

Related diseases are conditions that have similar signs and symptoms. A health care provider may consider these conditions in the table below when making a diagnosis. Please note that the table may not include all the possible conditions related to this disease.

Conditions with similar signs and symptoms from Orphanet
Differential diagnosis includes variants of PC (steatocystoma multiplex, which develops at puberty with little or no nail dystrophy, and focal non-epidermolytic palmoplantar keratoderma; see these terms) and disorders manifesting with dystrophic nails such as epidermolysis bullosa, Clouston syndrome (distinguished by the presence of alopecia), and acquired disorders such as psoriasis and lichen planus (see these terms).
Visit the Orphanet disease page for more information.

Research helps us better understand diseases and can lead to advances in diagnosis and treatment. This section provides resources to help you learn about medical research and ways to get involved.

Clinical Research Resources

  • ClinicalTrials.gov lists trials that are related to Pachyonychia congenita. Click on the link to go to ClinicalTrials.gov to read descriptions of these studies.

    Please note: Studies listed on the ClinicalTrials.gov website are listed for informational purposes only; being listed does not reflect an endorsement by GARD or the NIH. We strongly recommend that you talk with a trusted healthcare provider before choosing to participate in any clinical study.
  • Orphanet lists European clinical trials, research studies, and patient registries enrolling people with this condition. 

Patient Registry

Support and advocacy groups can help you connect with other patients and families, and they can provide valuable services. Many develop patient-centered information and are the driving force behind research for better treatments and possible cures. They can direct you to research, resources, and services. Many organizations also have experts who serve as medical advisors or provide lists of doctors/clinics. Visit the group’s website or contact them to learn about the services they offer. Inclusion on this list is not an endorsement by GARD.

Organizations Supporting this Disease

These resources provide more information about this condition or associated symptoms. The in-depth resources contain medical and scientific language that may be hard to understand. You may want to review these resources with a medical professional.

Where to Start

  • DermNet NZ is an online resource about skin diseases developed by the New Zealand Dermatological Society Incorporated. DermNet NZ provides information about this condition.
  • Genetics Home Reference (GHR) contains information on Pachyonychia congenita. This website is maintained by the National Library of Medicine.

In-Depth Information

  • GeneReviews provides current, expert-authored, peer-reviewed, full-text articles describing the application of genetic testing to the diagnosis, management, and genetic counseling of patients with specific inherited conditions.
  • Medscape Reference provides information on this topic. You may need to register to view the medical textbook, but registration is free.
  • The Monarch Initiative brings together data about this condition from humans and other species to help physicians and biomedical researchers. Monarch’s tools are designed to make it easier to compare the signs and symptoms (phenotypes) of different diseases and discover common features. This initiative is a collaboration between several academic institutions across the world and is funded by the National Institutes of Health. Visit the website to explore the biology of this condition.
  • Online Mendelian Inheritance in Man (OMIM) is a catalog of human genes and genetic disorders. Each entry has a summary of related medical articles. It is meant for health care professionals and researchers. OMIM is maintained by Johns Hopkins University School of Medicine. 
    Pachyonychia congenita 1
    Pachyonychia congenita 2
    Pachyonychia congenita 3
    Pachyonychia congenita 4
  • Orphanet is a European reference portal for information on rare diseases and orphan drugs. Access to this database is free of charge.
  • PubMed is a searchable database of medical literature and lists journal articles that discuss Pachyonychia congenita. Click on the link to view a sample search on this topic.

Questions sent to GARD may be posted here if the information could be helpful to others. We remove all identifying information when posting a question to protect your privacy. If you do not want your question posted, please let us know.

  1. Pachyonychia congenita. Genetics Home Reference. August 2012; http://ghr.nlm.nih.gov/condition/pachyonychia-congenita.
  2. Frances JD Smith, PhD, C David Hansen, MD, Peter R Hull, MD, PhD, FRCPC, Roger L Kaspar, PhD, Mary E Schwartz, LLD, WH Irwin McLean, DSc, FRSE, Leonard M Milstone, MD, Maurice van Steensel, MD, PhD, Edel O’Toole, MD, PhD, FRCPI, FRCP, and Eli Sprecher, MD, PhD. Pachyonychia Congenita. GeneReviews. July 2014; http://www.ncbi.nlm.nih.gov/books/NBK1280/.
  3. What is Pachyonychia Congenita?. Pachyonychia Congenita Project. https://www.pachyonychia.org/what-is-pc/. Accessed 12/10/2015.
  4. Newly Diagnosed With PC. Pachyonychia Congenita Project. https://www.pachyonychia.org/newly-diagnosed-with-pc/. Accessed 12/10/2015.
  5. Goldberg I1, Fruchter D, Meilick A, Schwartz ME, Sprecher E. Best treatment practices for pachyonychia congenita. J Eur Acad Dermatol Venereol. March 2014; 28(3):279-285. https://www.ncbi.nlm.nih.gov/pubmed/23363249.
  6. George SJ & Elston DM. Pachyonychia Congenita. Medscape Reference. March 2014; http://emedicine.medscape.com/article/1106169-overview#a4.