...MORE ABOUT PACHYONYCHIA CONGENITA
MUTATIONS THAT CAUSE PC
There are numerous different mutations that cause PC. Most medical literature offers two classifications of the mutations, known as PC-1 Jadassohn-Lewandowsky type and PC-2 Jackson-Lawler type. However, data collected from over 250 patients in the IPCRR (with genetically confirmed PC) clearly show that there are similarities and differences across all the genes and mutations. The genes do not pair up as described in medical literature into the two classifications. Therefore, reference to these subtypes does not assist in diagnosis or treatment and should be discontinued.
To access current statistical data from the International PC Research Registry, click here to register on the website. Extensive graphs and data are found on the IPCRR links.
DIAGNOSING PC—DO I REALLY HAVE PC?
PC can be diagnosed in two ways: by clinical diagnosis, or phenotype (where a physican makes a diagnosis based on the appearance of the features which the patient has), or by genetic diagnosis, or genotype (where the diagnosis is made based on determination of the specific mutation in the genes K6a, K16, K6b, and K17). However, reliance upon clinical diagnosis exclusively has led to misdiagnoses and even some confusion about the condition itself. Many articles written about 'pachyonychia congenita' written before genetic testing became available are actually about other diseases and about 10% of those diagnosed clinically with PC are found to not have PC based on the genetic findings. While clinical diagnosis is still important, genetic testing is the only way to verify that the patient's condition is in fact PC and not a related disorder.
Because this information is so essential to successful research, genetic testing (which costs up to $2,000 per test) is provided as an optional free benefit to those who register with the International PC Research Registry.
Mutations in other keratin genes cause PC-like phenotype conditions. For example, mutations in Connexin30 & certain mutations inK16 or K6C cause palmar and plantar keratoderma but no nail phenotype is found.
Other related disorders include ichthyotic conditions, epidermolysis bullosa and palmoplantar keratodermas. In some instances, PC patients have been tested for thrush, leukoplakia, and fungal infections of the nails before a correct diagnosis has been found.
Click here for Myths About Pachyonychia Congenita