ABOUT THE KRT16 GENE
The KRT16 gene provides instructions for making a protein called keratin 16 or K16. Keratins are a group of tough, fibrous proteins that form the structural framework of certain cells, particularly cells that make up the skin, hair, nails, and similar tissues. Keratin 16 is produced in the nails, the skin on the palms of the hands and soles of the feet, and the oral mucosa that lines the inside of the mouth. It has also been found in specialized pigment cells called melanocytes, although its function in these cells is unknown.
Keratin 16 partners with a similar protein, keratin 6a, to form molecules called keratin intermediate filaments. These filaments assemble into dense networks that provide strength and resiliency to the skin, nails, and other tissues. Networks of keratin filaments protect these tissues from being damaged by friction and other everyday physical stresses. Keratin 16 is also among several keratins involved in wound healing.
The KRT16 mutations responsible for pachyonychia congenita change the structure of keratin 16, preventing it from working effectively with keratin 6a and interfering with the assembly of the keratin intermediate filament network. Without this network, skin cells become fragile and are easily damaged, making the skin less resistant to friction and minor trauma. Even normal activities such as walking can cause skin cells to break down, resulting in the formation of painful blisters and calluses. Additionally, fragile skin cells may abnormally produce more keratin in response to damage, which makes the skin problems worse.
Defective keratin 16 also disrupts the growth and function of cells in the nails and oral mucosa, which explains why the signs and symptoms of pachyonychia congenita also affect these tissues. (Adapted from http://ghr.nlm.nih.gov/gene/KRT16.)
To learn how many others have mutations in the same gene and the same mutation, visit the PC data page where there is detailed information on those with PC and the various mutations.
Observations on PC-K16 from the IPCRR
Depending on the specific mutation, patients with mutations in PC-K16 may have (a) extremely thickened nails or (b) little/no nail dystrophy. Painful plantar keratoderma is the most challenging feature for PC-K16.
- The condition is not usually evident at birth, but almost 100% have phenotype before age 14.
- Plantar keratoderma and pain is experienced by nearly 100% of PC-K16 patients by age 10. Pain levels for PC-K16 patients are often from 4 to 9 on a 0 to 10 scale.
- Some with PC-K16 also have palmar keratoderma.
- Oral leukokeratosis, cysts or follicular hyperkeratosis are found in only a small percentage of PC-K16 patients.
IPCRR Data for PC-K16
|Always (never goes away)||98%|
|Sometimes (clears up at times)||1%|
|Seldom (feet usually clear)||0%|
|Plantar Keratoderma – Onset|
|Birth or less than 1 year||10%|
|1 to 4 years old||51%|
|5 to 14 years old||36%|
|15 years and over||4%|
|Often require medications for pain||30%|
|Very painful, but do not use medications||45%|
|Always (never goes away)||53%|
|Sometimes (clears up at times)||8%|
|Seldom (hands usually clear)||10%|
|all 10 toenails thickened||38%|
|7-9 toenails thickened||14%|
|4-6 toenails thickened||26%|
|1-3 toenails thickened||20%|
|Toenails – Onset|
|Birth or less than 1 year||17%|
|1 to 4 years old||30%|
|5 to 14 years old||33%|
|15 years and over||19%|
|all 10 toenails thickened||27%|
|7-9 toenails thickened||4%|
|4-6 toenails thickened||12%|
|1-3 toenails thickened||13%|
|Fingernails – Onset|
|Birth or less than 1 year||19%|
|1 to 4 years old||28%|
|5 to 14 years old||26%|
|15 years and over||28%|
|Natal or Prenatal Teeth||1%|
Data from 2021 Sample Size N=338
One PC-K16 Patient’s Care Story
So my PC K16 care:
Basically I have 3 main tools. Clippers, Ped-Egg, and a Razor Blade with a handle.
At least weekly I’m trimming something.
I have to interject here that I use another tool, a man tool. A 3×21 belt sander (craftsman) for my large toe nails, and finger nails. I have a spot in the garage I go and sit, take off my shoes socks and flatten my two big toe nails. I don’t waste time with a Dremel tool because its to slow for me but it will work. I’ll also put the sander on my workbench and shorten the height of some of my finger nails.
Clippers mainly for my toe nails and small calluses around my toes. The Ped-Egg works well when the calluses are dry or really wet after soaking. I’ll sit on the bathtub edge and do my feet or outside in the yard if it’s a nice day. The Ped-Egg will only work a couple times and then the calluses become a hard shell as they grow. Then I really need to use the razor blade to cut them down and “soften” them back up. I usually leave my feet calluses thickness anywhere around 1/8 of an inch. I don’t take them down to far because after I use the razor blade, for a day they are sore walking. It’s much easier to cut them after a soaking. I try to keep the calluses clean and neat looking seems to feel the best for me. By the way I have flat feet and still wear the same type of sneakers I’ve been wearing for 35 years.
I know when they’re getting too thick because there’ll be a certain type of pain I feel for a couple days knowing that I have to cut them down.
I’m bad at taking the time but we need to. We brush our teeth everyday but I don’t take time for my feet.
I use my belt sander again just because it’s very quick at taking the nails height down. I then use a coarse nail file for my finger nails for shortening the length. I don’t do all my nails with the belt sander, just the really high ones.
I use the clippers or ped-egg to keep the clauses down on my hands. The Ped-egg works nice because it keeps them smooth.
Also, I have a electric rotary pummel stone tool I got from Costco. It works very nice but takes awhile so I don’t use it that often. My hands are really smooth after using it.
PCers are all different but I need socks and shoes. Unlike our K6 Brothers and sisters who prefer sandals. Wintertime is rougher because my feet really dry out and the calluses stay hard.
Best yet, after a long soak or swim using the Ped-Egg. My feet will be tender for the rest of the day but going forward for a week will feel fantastic. The newest swim or water shoes for the pool and beach are proof we are living in a wonderful time. I can remember when I was younger walking around the beach barefoot, very slowly and in pain.
Petroleum Jelly on my feet every day, Works quicker if it’s just after a shower.
I’m sure right after I send this email more will come to me. If anyone receives this email has questions please feel free to call or email.
Hope this helps!