@article {747, title = {Mutations in KRT10 in epidermolytic acanthoma.}, journal = {J Cutan Pathol}, volume = {47}, year = {2020}, month = {2020 Jun}, pages = {524-529}, abstract = {

BACKGROUND: Epidermolytic acanthoma (EA) is a rare acquired lesion demonstrating a characteristic histopathological pattern of epidermal degeneration referred to as epidermolytic hyperkeratosis (EHK). On histopathological analysis, EA appears nearly identical to inherited EHK-associated dermatoses such as epidermolytic ichthyosis and ichthyosis bullosa of Siemens. While it has been speculated that EA is caused by mutations in KRT10, KRT1, or KRT2 found in these inherited dermatoses, none have yet been identified. Herein, we aim to identify the contributions of keratin mutations to EA.

METHODS: Using genomic DNA extracted from paraffin-embedded samples from departmental archives, we evaluated a discovery cohort using whole-exome sequencing (WES) and assessed remaining samples using Sanger sequencing screening and restriction fragment length polymorphism (RFLP) analysis.

RESULTS: DNA from 16/20 cases in our sample was of sufficient quality for polymerase chain reaction amplification. WES of genomic DNA from lesional tissue revealed KRT10 c.466C > T, p.Arg156Cys mutations in 2/3 samples submitted for examination. RFLP analysis of these samples as well as eight additional samples confirmed the mutations identified via WES and identified four additional cases with Arg156 mutations. In sum, 6/11 screened cases showed hotspot mutation in KRT10.

CONCLUSIONS: Hotspot mutations in the Arg156 position of KRT10, known to cause epidermolytic ichthyosis, also underlie EA.

}, keywords = {Acanthoma, Adult, Aged, Aged, 80 and over, Female, Genomics, Humans, Hyperkeratosis, Epidermolytic, Ichthyosis Bullosa of Siemens, Keratin-10, Keratins, Male, Middle Aged, Mutation, Skin Neoplasms, Whole Exome Sequencing}, issn = {1600-0560}, doi = {10.1111/cup.13664}, author = {Cheraghlou, Shayan and Atzmony, Lihi and Roy, Simon F and McNiff, Jennifer M and Choate, Keith A} } @article {61, title = {Somatic Mutations in NEK9 Cause Nevus Comedonicus.}, journal = {Am J Hum Genet}, volume = {98}, year = {2016}, month = {2016 May 05}, pages = {1030-1037}, abstract = {

Acne vulgaris (AV) affects most adolescents, and of those affected, moderate to severe disease occurs in 20\%. Comedones, follicular plugs consisting of desquamated keratinocytes and sebum, are central to its pathogenesis. Despite high heritability in first-degree relatives, AV genetic determinants remain incompletely understood. We therefore employed whole-exome sequencing (WES) in nevus comedonicus (NC), a rare disorder that features comedones and inflammatory acne cysts in localized, linear configurations. WES identified somatic NEK9 mutations, each affecting highly conserved residues within its kinase or RCC1 domains, in affected tissue of three out of three NC-affected subjects. All mutations are gain of function, resulting in increased phosphorylation at Thr210, a hallmark of NEK9 kinase activation. We found that comedo formation in NC is marked by loss of follicular differentiation markers, expansion of keratin-15-positive cells from localization within the bulge to the entire sub-bulge follicle and cyst, and ectopic expression of keratin 10, a marker of interfollicular differentiation not present in normal follicles. These findings suggest that NEK9 mutations in NC disrupt normal follicular differentiation and identify NEK9 as a potential regulator of follicular homeostasis.

}, keywords = {Adolescent, Adult, Child, Female, Fluorescent Antibody Technique, High-Throughput Nucleotide Sequencing, Humans, Male, Mutation, Nevus, NIMA-Related Kinases, Prognosis, Skin Neoplasms, Young Adult}, issn = {1537-6605}, doi = {10.1016/j.ajhg.2016.03.019}, author = {Levinsohn, Jonathan L and Sugarman, Jeffrey L and McNiff, Jennifer M and Antaya, Richard J and Choate, Keith A} } @article {187, title = {Frequent somatic reversion of KRT1 mutations in ichthyosis with confetti.}, journal = {J Clin Invest}, volume = {125}, year = {2015}, month = {2015 Apr}, pages = {1703-7}, abstract = {

Widespread reversion of genetic disease is rare; however, such events are particularly evident in some skin disorders in which normal clones develop on a background of affected skin. We previously demonstrated that mutations in keratin 10 (KRT10) cause ichthyosis with confetti (IWC), a severe dominant disorder that is characterized by progressive development of hundreds of normal skin spots via revertant mosaicism. Here, we report on a clinical and histological IWC subtype in which affected subjects have red, scaly skin at birth, experience worsening palmoplantar keratoderma in childhood, and develop hundreds of normal skin spots, beginning at around 20 years of age, that increase in size and number over time. We identified a causal de novo mutation in keratin 1 (KRT1). Similar to IWC-causing KRT10 mutations, this mutation in KRT1 resulted in a C-terminal frameshift, replacing 22 C-terminal amino acids with an alternate 30-residue peptide. Mutant KRT1 caused partial collapse of the cytoplasmic intermediate filament network and mislocalized to the nucleus. As with KRT10 mutations causing IWC, reversion of KRT1 mutations occurred via mitotic recombination. Because reversion is not observed with other disease-causing keratin mutations, the results of this study implicate KRT1 and KRT10 C-terminal frameshift mutations in the high frequency of revertant mosaicism in IWC.

}, keywords = {Adult, Age of Onset, Amino Acid Sequence, Cell Line, Tumor, Cell Nucleus, Child, Child, Preschool, Chromosomes, Human, Pair 12, Cytoskeleton, Frameshift Mutation, Humans, Ichthyosis, Intermediate Filaments, Keratin-1, Keratinocytes, Loss of Heterozygosity, Male, Molecular Sequence Data, Mosaicism, Phenotype, Polymorphism, Single Nucleotide, Protein Transport, Transfection}, issn = {1558-8238}, doi = {10.1172/JCI64415}, author = {Choate, Keith A and Lu, Yin and Zhou, Jing and Elias, Peter M and Zaidi, Samir and Paller, Amy S and Farhi, Anita and Nelson-Williams, Carol and Crumrine, Debra and Milstone, Leonard M and Lifton, Richard P} } @article {125, title = {Somatic p.T771R KDR (VEGFR2) Mutation Arising in a Sporadic Angioma During Ramucirumab Therapy.}, journal = {JAMA Dermatol}, volume = {151}, year = {2015}, month = {2015 Nov}, pages = {1240-3}, abstract = {

IMPORTANCE: Inhibition of angiogenesis is an effective anticancer strategy because neoplasms require a rich blood supply. Ramucirumab, approved by the US Food and Drug Administration in 2014 to treat gastric adenocarcinomas and non-small cell lung carcinomas, targets vascular endothelial growth factor 2 (VEGFR2). We identified a patient prescribed a regimen of irinotecan hydrochloride, cetuximab, and ramucirumab for metastatic rectal cancer (diagnosed in November 2013 and treated through early January 2015) who developed a new-onset, expanding vascular lesion on his right leg. Via exome sequencing, we found that the lesion contained a single somatic mutation in KDR (encodes VEGFR2), possibly in response to ramucirumab. Vascular tumors are not a known complication of antiangiogenic therapeutics.

OBSERVATIONS: Exome sequencing of the well-demarcated, blanching vascular lesion on the lateral right shin revealed a somatic p.T771R mutation in KDR, without evidence of other somatic mutations or loss of heterozygosity. Histological features included lobules of small vessels within the dermis, resembling a tufted angioma.

CONCLUSIONS AND RELEVANCE: A potential adverse effect of ramucirumab in combination therapy is the development of sporadic angiomas. The p.T771R mutation was previously implicated in autophosphorylation of VEGFR2 and reported in angiosarcomas alongside other driver mutations. Our observations suggest that this mutation confers a proliferative advantage in the setting of ramucirumab therapy. Patients receiving ramucirumab should be monitored for the development of new vascular lesions.

}, keywords = {Adult, Angiogenesis Inhibitors, Antibodies, Monoclonal, Antineoplastic Combined Chemotherapy Protocols, Camptothecin, Cetuximab, Hemangioma, Humans, Irinotecan, Male, Mutation, Rectal Neoplasms, Skin Neoplasms, Vascular Endothelial Growth Factor Receptor-2}, issn = {2168-6084}, doi = {10.1001/jamadermatol.2015.1925}, author = {Lim, Young H and Odell, Ian D and Ko, Christine J and Choate, Keith A} } @article {318, title = {Whole-exome sequencing reveals somatic mutations in HRAS and KRAS, which cause nevus sebaceus.}, journal = {J Invest Dermatol}, volume = {133}, year = {2013}, month = {2013 Mar}, pages = {827-830}, keywords = {Adolescent, Adult, Amino Acid Sequence, Biopsy, Child, Child, Preschool, Cohort Studies, Epidermis, Exome, Humans, Infant, Middle Aged, Molecular Sequence Data, Mutation, Nevus, Sebaceous of Jadassohn, Proto-Oncogene Proteins, Proto-Oncogene Proteins p21(ras), ras Proteins, Sequence Analysis, DNA, Young Adult}, issn = {1523-1747}, doi = {10.1038/jid.2012.379}, author = {Levinsohn, Jonathan L and Tian, Li C and Boyden, Lynn M and McNiff, Jennifer M and Narayan, Deepak and Loring, Erin S and Yun, Duri and Sugarman, Jeffrey L and Overton, John D and Mane, Shrikant M and Lifton, Richard P and Paller, Amy S and Wagner, Annette M and Antaya, Richard J and Choate, Keith A} }