Dermatological Phenotype in Costello Syndrome: Consequences of Ras Dysregulation in Development.
D.H. Siegela*, J.A. Mann b*, A.L. Krolc, K.A. Rauend
a Department of Dermatology and Pediatrics, Medical College of Wisconsin, Milwaukee, WI
b Department of Dermatology, Oregon Health & Science University, Portland, OR
c Department of Dermatology and Pediatrics, Oregon Health & Science University, Portland, OR
d Department of Pediatrics, University of California San Francisco, San Francisco, CA
Dawn Siegel, MD, Department of Dermatology, Medical College of Wisconsin,
Background: The RASopathies are a class of human genetic syndromes caused by germline mutations in genes that encode protein components of the Ras/mitogen-activated protein kinase (MAPK) pathway. Costello syndrome (CS) is a RASopathy caused by mutations in the HRAS gene, a key regulator of signal transduction.
To quantify the specific cutaneous phenotype observed in 46 individuals with Costello syndrome with confirmed HRAS mutations
This was a cross-sectional study. Dermatologic surveys were designed by the authors and were completed by parents of mutation-positive CS individuals at the Costello Syndrome Family Network (CSFN) conferences in 2007 and 2009. Dermatologic exams were performed by the authors at the CSFN conferences.
Cutaneous papillomas are reported in 33/46 (71.7%) of participants, with age of onset ranging from infancy to 22 years. Individuals with CS are more likely than patients with cardiofacio-cutaneous syndrome (CFC) to present with cutaneous papillomas (71.7% compared to 4.9%, p<0.001) and palmoplantar keratoderma (76.1% compared to 36.1%, p<0.001). Individuals with CS are less likely than individuals with CFC to present with sparse or absent eyebrows (8.7% compared to 90.2%, p<0.001) or keratosis pilaris (32.6% compared to 80.3%, p=0.001). This study also identified that loose, redundant skin on the hands and feet, “stippled” dermatoglyphs (pachydermatoglyphia) on the fingertips 8/26 (31%), and acanthosis nigricans 17/46 (37%) are frequent features of CS.
While there is significant phenotypic overlap among syndromes of the Ras/MAPK pathway, individuals with CS are more likely than individuals with CFC syndrome to present with cutaneous papillomas, palmoplantar keratoderma and full eyebrows, and are less likely to present with ulerythema ophryogenes, keratosis pilaris or multiple naevi. The dermatologic features of CS, a Ras dysregulation syndrome, share many features with cutaneous paraneoplastic syndromes. This may provide further insight into the role of Ras signaling in cutaneous paraneoplastic syndromes.
Palmoplantar Keratoderma in Costello Syndrome Responsive to Acitretin
Nareh V. Marukian, B.A.,* Jonathan L. Levinsohn, B.A.,* Brittany G. Craiglow, M.D.,*,† Leonard M. Milstone, M.D.,* and Keith A. Choate, M.D., Ph.D.*,‡,¶
Departments of *Dermatology, †Pediatrics, ‡Genetics, and ¶Pathology, School of Medicine, Yale University, New Haven, Connecticut
Costello syndrome (CS) is a multisystem congenital disorder characterized by coarse facial features, cardiac defects, intellectual disability, and predisposition to malignancies. Dermatologic findings can include cutaneous papillomas, skin redundancy, acanthosis nigricans, and keratosis pilaris. Palmoplantar keratoderma (PPK) is present in approximately 76% of patients with CS, with disabling functional consequences in severe cases. We report a case of CS with severe PPK that improved dramatically with systemic administration of acitretin 0.3 mg/ kg/day.