Rare Cardiology News

Disease Profile

Papular epidermal nevi with skyline basal cell layers syndrome

Prevalence estimates on Rare Medical Network websites are calculated based on data available from numerous sources, including US and European government statistics, the NIH, Orphanet, and published epidemiologic studies. Rare disease population data is recognized to be highly variable, and based on a wide variety of source data and methodologies, so the prevalence data on this site should be assumed to be estimated and cannot be considered to be absolutely correct.


Age of onset





Autosomal dominant A pathogenic variant in only one gene copy in each cell is sufficient to cause an autosomal dominant disease.


Autosomal recessive Pathogenic variants in both copies of each gene of the chromosome are needed to cause an autosomal recessive disease and observe the mutant phenotype.


dominant X-linked dominant inheritance, sometimes referred to as X-linked dominance, is a mode of genetic inheritance by which a dominant gene is carried on the X chromosome.


recessive Pathogenic variants in both copies of a gene on the X chromosome cause an X-linked recessive disorder.


Mitochondrial or multigenic Mitochondrial genetic disorders can be caused by changes (mutations) in either the mitochondrial DNA or nuclear DNA that lead to dysfunction of the mitochondria and inadequate production of energy.


Multigenic or multifactor Inheritance involving many factors, of which at least one is genetic but none is of overwhelming importance, as in the causation of a disease by multiple genetic and environmental factors.


Not applicable


Other names (AKA)

Papular Epidermal Nevus with Skyline Basal Cell Layer (PENS); Papular Epidermal Nevus with "Skyline" Basal Cell Layer Syndrome; PENS syndrome


Papular epidermal nevus with "skyline" basal cell layer syndrome (PENS) is a very rare type of keratinocytic epidermal nevi that includes a specific type of skin lesion and can be associated with other birth defects and neurological problems.[1][2][3][4][5] The skin lesions appear as small, slightly scaly, pimples (papules) made of the thickened outer layer of the skin (hyperkerotosis) with a rough, flat surface.[5] The skin lesions may be visible at birth or soon after birth. There may be one lesion or multiple lesions anywhere on the body. The color of the skin lesions varies from white to brown and the shape may vary as well. Neurological symptoms, such as mild intellectual disability, seizures, and delayed development of mental and movement abilities (psychomotor delay), are present in about 50% of the cases. Psychomotor delay may appear as clumsiness or difficulty playing sports.[1][2][3][4][5] Deafness, unusual facial features, and genital birth defects, such as hypospadius or a curved penis, have been described in a few cases.[2][3][4]

The diagnosis of PENS may be confirmed by a biopsy of the skin lesion and/or examination of the skin lesion and surrounding skin under a special microscope (dermoscopy).[1][2][3][4] When there are four or more skin lesions, examination for neurological symptoms may be suggested.[4] The cause of the PENS is not known, but there are several cases where more than one member of a family is affected.[2][4] Treatment depends on the associated problems and may include surgery to correct genital birth defects, anti-seizure medication, and early intervention or extra help in school. In all presently described cases, the skin lesions have remained stable and benign and have not required treatment. When present, the neurological symptoms do not appear progressive, and in several cases, the seizures and psychomotor delays improved with age.[1][2][3][4]


  1. Torrelo A, Colmenero I, Kristal L, Navarro L, Hafner C, Hernández-Martín A, Requena L & Happle R. . Papular epidermal nevus with "skyline" basal cell layer (PENS). J Am Acad Dermatol. May, 2011; 64(5):888-92. https://www.ncbi.nlm.nih.gov/pubmed/21315481.
  2. Zahn CA & Itin P. Papular Epidermal Nevus with "Skyline" Basal Cell Layer Syndrome Natural Course: Case Report and Literature Review. Case Rep Dermatol. January-April, 2017; 9(1):1-5. https://www.karger.com/Article/FullText/454757.
  3. Balestri R, Rizzoli L, Rech G &Girardelli CR. Dermoscopy of Papular Epidermal Nevus with Skyline Basal Cell Layer. Pediatr Dermatol. March, 2017; 34(2):99-101. https://onlinelibrary.wiley.com/doi/10.1111/pde.13070/full.
  4. Luna PC, Pannizardi AA, Martin CI, Vigovich F, Casas JG & Larralde M. Papular Epidermal Nevus with Skyline Basal Cell Layer (PENS): Three New Cases and Review of the Literature. Pediatr Dermatol. May, 2016; 33(3):296-300. https://www.ncbi.nlm.nih.gov/pubmed/26939784.
  5. Rodríguez-Díaz E, Gonzalvo P, Colmenero I, Requena L, Hernández-Martín A, Torrelo A. Papular epidermal nevus with "skyline" basal cell layer (PENS) with extracutaneous findings. Pediatr Dermatol. July, 2013; 30(4):e54-6. https://www.ncbi.nlm.nih.gov/pubmed/22985090.