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Pachyonychia congenita type 2(PC2)

MedGen UID:
314107
Concept ID:
C1721007
Congenital Abnormality; Disease or Syndrome
Synonyms: Jackson-Lawler syndrome; KRT17-Related Pachyonychia Congenita; KRT6B-Related Pachyonychia Congenita; Pachyonychia congenita Jackson Lawler type; PC-K17; PC2
Modes of inheritance:
Heterogeneous
MedGen UID:
67020
Concept ID:
C0242960
Organism Attribute
Source: HPO
The production of the same or similar phenotypes (observed biochemical, physiological, and morphological characteristics of a person determined by his/her genotype) by different genetic mechanisms. There are two types: (1) allelic heterogeneity - when different alleles at a locus can produce variable expression of a condition; and (2) locus heterogeneity - the term used to describe disease in which mutations at different loci can produce the same disease phenotype.
Autosomal dominant inheritance
MedGen UID:
141047
Concept ID:
C0443147
Intellectual Product
Sources: HPO, OMIM, Orphanet
Autosomal dominant inheritance refers to genetic conditions that occur when a mutation is present in one copy of a given gene (i.e., the person is heterozygous).
Autosomal dominant inheritance (HPO, OMIM, Orphanet)
 
Gene (location): KRT17 (17q21.2)
OMIM®: 167210

Disease characteristics

Excerpted from the GeneReview: Pachyonychia Congenita
Pachyonychia congenita (PC) is characterized by hypertrophic nail dystrophy, painful palmoplantar keratoderma and blistering, oral leukokeratosis, pilosebaceous cysts (including steatocystoma and vellus hair cysts), palmoplantar hyperhydrosis, and follicular keratoses on the trunk and extremities. [from GeneReviews]
Authors:
Frances JD Smith  |  C David Hansen  |  Peter R Hull, et. al.   view full author information

Additional descriptions

From OMIM
Pachyonychia congenita (PC) is an autosomal dominant genodermatosis with the main clinical features of hypertrophic nail dystrophy, painful and highly debilitating plantar keratoderma, oral leukokeratosis, and a variety of epidermal cysts. Although the condition had previously been subdivided clinically into Jadassohn-Lewandowsky PC type 1 and Jackson-Lawler PC type 2, patients with PC were later found to have a mixed constellation of both types, leading to a classification of PC based on genotype (summary by Sybert, 2010; Eliason et al., 2012; McLean et al., 2011). For a discussion of genetic heterogeneity of pachyonychia congenita, see 167200. Historical Classification of Pachyonychia Congenita Gorlin et al. (1976) suggested that 2 distinct syndromes are subsumed under the designation pachyonychia congenita. PC type 1, the Jadassohn-Lewandowsky type, shows oral leukokeratosis. PC type 2, the Jackson-Lawler type, has natal teeth and epidermoid cysts (cylindromas), but no oral leukoplakia. Corneal dystrophy may be a feature exclusively of the Jackson-Lawler type. Smith et al. (1998) stated that PC type 2, in contrast to PC type 1, has minimal oral involvement and milder keratoderma, and multiple steatocystomas (184500) is a major clinical feature. Steatocystoma, also known as eruptive vellus cyst, is a cystic hamartoma lined by sebaceous ductal epithelium. On the basis of a study of 13 patients with PC type 1 or type 2, Terrinoni et al. (2001) concluded that the presence of pilosebaceous cysts following puberty is the best indicator of PC type 2; prepubescent patients are more difficult to classify due to the lack of cysts. Natal teeth are indicative of PC type 2, although their absence does not preclude the PC type 2 diagnosis.  http://www.omim.org/entry/167210
From GHR
Pachyonychia congenita is a condition that primarily affects the nails and skin. The signs and symptoms of this condition usually become apparent within the first few months of life.Almost everyone with pachyonychia congenita has hypertrophic nail dystrophy, which causes the fingernails and toenails to become thick and abnormally shaped. Many affected children also develop very painful blisters and calluses on the soles of the feet and, less commonly, on the palms of the hands. This condition is known as palmoplantar keratoderma. Severe blisters and calluses on the feet can make it painful or impossible to walk.Pachyonychia congenita can have several additional features, which vary among affected individuals. These features include thick, white patches on the tongue and inside of the cheeks (oral leukokeratosis); bumps called follicular keratoses that develop around hair follicles on the elbows, knees, and waistline; cysts in the armpits, groin, back, or scalp; and excessive sweating on the palms and soles (palmoplantar hyperhidrosis). Some affected individuals also develop widespread cysts called steatocystomas, which are filled with an oily substance called sebum that normally lubricates the skin and hair. Some babies with pachyonychia congenita have prenatal or natal teeth, which are teeth that are present at birth or in early infancy. Rarely, pachyonychia congenita can affect the voice box (larynx), potentially leading to hoarseness or breathing problems.Researchers used to split pachyonychia congenita into two types, PC-1 and PC-2, based on the genetic cause and pattern of signs and symptoms. However, as more affected individuals were identified, it became clear that the features of the two types overlapped considerably. Now researchers prefer to describe pachyonychia congenita based on the gene that is altered.  https://ghr.nlm.nih.gov/condition/pachyonychia-congenita

Clinical features

Hereditary palmoplantar keratoderma
MedGen UID:
44017
Concept ID:
C0022596
Disease or Syndrome
Hyperkeratosis affecting the palm of the hand and the sole of the foot.
Hoarse voice
MedGen UID:
5602
Concept ID:
C0019825
Sign or Symptom
Hoarseness refers to a change in the pitch or quality of the voice, with the voice sounding weak, very breathy, scratchy, or husky.
Subungual hyperkeratosis
MedGen UID:
21379
Concept ID:
C0038605
Finding
A thickening of the stratum corneum in the region beneath the nails.
Dystrophia unguium
MedGen UID:
66368
Concept ID:
C0221260
Disease or Syndrome
Onychodystrophy (nail dystrophy) refers to nail changes apart from changes of the color (nail dyschromia) and involves partial or complete disruption of the various keratinous layers of the nail plate.
Steatocystoma multiplex
MedGen UID:
75476
Concept ID:
C0259771
Neoplastic Process
Steatocystoma multiplex is a skin disorder characterized by the development of multiple noncancerous (benign) cysts known as steatocystomas. These growths begin in the skin's sebaceous glands, which normally produce an oily substance called sebum that lubricates the skin and hair. Steatocystomas are filled with sebum.In affected individuals, steatocystomas typically first appear during adolescence and are found most often on the torso, neck, upper arms, and upper legs. These cysts are usually the only sign of the condition. However, some affected individuals also have mild abnormalities involving the teeth or the fingernails and toenails.
Dry hair
MedGen UID:
75809
Concept ID:
C0277960
Finding
Hair that lacks the lustre (shine or gleam) of normal hair.
Sparse eyebrow
MedGen UID:
371332
Concept ID:
C1832446
Finding
Decreased density/number and/or decreased diameter of eyebrow hairs.
Nail dysplasia
MedGen UID:
331737
Concept ID:
C1834405
Disease or Syndrome
The presence of developmental dysplasia of the nail.
Sparse scalp hair
MedGen UID:
346499
Concept ID:
C1857042
Finding
Decreased number of head hairs per unit area.

Term Hierarchy

CClinical test,  RResearch test,  OOMIM,  GGeneReviews,  VClinVar  

Recent clinical studies

Etiology

Tsuda T, Ishikawa C, Nakagawa N, Konishi H, Tarutani M, Matsuki M, Yamanishi K
Br J Dermatol 2008 Sep;159(3):730-2. Epub 2008 Jun 28 doi: 10.1111/j.1365-2133.2008.08684.x. PMID: 18547302
Feng YG, Xiao SX, Ren XR, Wang WQ, Liu A, Pan M
Br J Dermatol 2003 Mar;148(3):452-5. PMID: 12653736
Terrinoni A, Smith FJ, Didona B, Canzona F, Paradisi M, Huber M, Hohl D, David A, Verloes A, Leigh IM, Munro CS, Melino G, McLean WH
J Invest Dermatol 2001 Dec;117(6):1391-6. doi: 10.1046/j.0022-202x.2001.01565.x. PMID: 11886499
Smith FJ, Jonkman MF, van Goor H, Coleman CM, Covello SP, Uitto J, McLean WH
Hum Mol Genet 1998 Jul;7(7):1143-8. PMID: 9618173
Smith FJ, Corden LD, Rugg EL, Ratnavel R, Leigh IM, Moss C, Tidman MJ, Hohl D, Huber M, Kunkeler L, Munro CS, Lane EB, McLean WH
J Invest Dermatol 1997 Feb;108(2):220-3. PMID: 9008238

Diagnosis

Morais P, Peralta L, Loureiro M, Coelho S
Acta Dermatovenerol Croat 2013;21(1):48-51. PMID: 23683487
Cogulu O, Onay H, Aykut A, Wilson NJ, Smith FJ, Dereli T, Ozkinay F
Eur J Pediatr 2009 Oct;168(10):1269-72. Epub 2008 Dec 24 doi: 10.1007/s00431-008-0908-6. PMID: 19107515
Oh Adib C, Jones B, Liao H, Smith FJ, Solomon R, Egan CA, Leachman S
Arch Dermatol Res 2008 Jun;300(5):211-4. Epub 2008 Mar 18 doi: 10.1007/s00403-008-0840-7. PMID: 18347808
Terrinoni A, Smith FJ, Didona B, Canzona F, Paradisi M, Huber M, Hohl D, David A, Verloes A, Leigh IM, Munro CS, Melino G, McLean WH
J Invest Dermatol 2001 Dec;117(6):1391-6. doi: 10.1046/j.0022-202x.2001.01565.x. PMID: 11886499
Smith FJ, Corden LD, Rugg EL, Ratnavel R, Leigh IM, Moss C, Tidman MJ, Hohl D, Huber M, Kunkeler L, Munro CS, Lane EB, McLean WH
J Invest Dermatol 1997 Feb;108(2):220-3. PMID: 9008238

Prognosis

Xiao SX, Feng YG, Ren XR, Tan SS, Li L, Wang JM, Shi YZ
J Invest Dermatol 2004 Apr;122(4):892-5. doi: 10.1111/j.0022-202X.2004.22408.x. PMID: 15102078
Feng YG, Xiao SX, Ren XR, Wang WQ, Liu A, Pan M
Br J Dermatol 2003 Mar;148(3):452-5. PMID: 12653736

Clinical prediction guides

Xiao SX, Feng YG, Ren XR, Tan SS, Li L, Wang JM, Shi YZ
J Invest Dermatol 2004 Apr;122(4):892-5. doi: 10.1111/j.0022-202X.2004.22408.x. PMID: 15102078
Feng YG, Xiao SX, Ren XR, Wang WQ, Liu A, Pan M
Br J Dermatol 2003 Mar;148(3):452-5. PMID: 12653736
Smith FJ, Corden LD, Rugg EL, Ratnavel R, Leigh IM, Moss C, Tidman MJ, Hohl D, Huber M, Kunkeler L, Munro CS, Lane EB, McLean WH
J Invest Dermatol 1997 Feb;108(2):220-3. PMID: 9008238

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