Exploring the Emergence of Genomic Testing in Dermatology

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Genomics, the study of the entire genome encompassing genetic and epigenetic information, is emerging in both general medicine and dermatology as an opportunity to improve medical diagnoses and treatment, according to a recent article published in the Journal of Dermatology Physician Assistants.¹

Researchers Love et al explored and reviewed the role of genomics in several areas of medicine and dermatology, noting that the overall understanding of their role in the health care space is limited. However, these tests are becoming more accessible and affordable.

While often used interchangeably, genomics and genetics differ in scope. Genetics focuses on individual genes, their hereditary function, and composition, predominantly examining variations within a single gene as a cause of health conditions. Genomics, however, delves into the entire genome, exploring the interactions of genetic and epigenetic factors, including DNA and RNA. Epigenetics, a critical facet of genomics, studies how external factors modify gene expression without altering the gene code.

In dermatology, genomics has made early strides, including in the analysis of the skin microbiome, gene-expression profiling for neoplasms, and mutational analyses of inherited skin diseases. Advancements like adhesive patches for evaluating atopic dermatitis and psoriasis have demonstrated the potential of less invasive genomic methods in dermatologic diseases.

Specific genomic tests have emerged for pigmented lesions and melanoma. The DermTech Melanoma Test, for example, utilizes non-invasive adhesive patches, offering a biopsy decision aid. MyPath Melanoma provides genomic insights for categorizing challenging melanocytic lesions and DecisionDx-Melanoma acts as a risk stratification tool, aiding in treatment decisions for stage I to III melanoma patients.

For cutaneous squamous cell carcinoma, the DecisionDx-SCC test provides objective information about the risk of distant or nodal metastasis. This test aids in risk-appropriate management decisions, potentially saving patients from unnecessary invasive procedures.

Genomic testing has also expanded into inflammatory skin diseases, offering insights through tape strips for atopic dermatitis and psoriasis. Mindera Health's Mind.Px has introduced a theranostic approach for psoriasis, predicting patient response to specific biologic treatments.

Post-zygotic mutation testing has found its way into rare skin diseases, such as epidermolysis bullosa. GeneDx utilizes buccal swabs to determine variants and subtypes, shedding light on the genetic landscape of these conditions.

Recently, Castle Biosciences, Inc., funded a study wherein they found that utilizing the 40-gene expression profile test to determine which patients with skin cancer will benefit most from adjuvant radiation therapy could result in significant health care savings while avoiding overtreatment.²

Read more from Dermatology Times here.

Additionally, 2024 Winter Clinical Hawaii Dermatology Conference included a poster from DermTech titled, “Non-invasive Gene Expression Analysis Rules Out Melanoma With High Negative Predictive Value Regardless of Skin Phototype,” wherein DermTech’s 2-gene expression profiling assay was used to detect the expression of LINC00518 and PRAME as a non-invasive assessment of clinically atypical, pigmented skin lesions to rule out melanoma with a negative predictive value of 99%. Study author Maral Kibarian Skelsey, MD, spoke with Dermatology Times of the results and their implications. Read more here.

References

1. Love J, Blair A, DiRuggiero D. Genomics in dermatology/precision medicine-more than sequence. JDPA. 2023;17(4).
2. Somani A, Ibrahim SF, Tassavor M, Yoo J, Farberg AS. Use of the 40-gene expression profile (40-GEP) test in Medicare-eligible patients diagnosed with cutaneous squamous cell carcinoma (cscc) to guide adjuvant radiation therapy (ART) decisions leads to a significant reduction in healthcare costs. J Clin Aesthet Dermatol. 2024;17(1):41–44.