CMM8; MI; WS2; WS2A; bHLHe32
The MITF gene is associated with an increased risk for autosomal dominant cutaneous malignant melanoma (MedGen UID: 463554).
Order this gene as a single gene test.
MITF: Analysis is limited to the NM_000248.3:c.952G>A p.Glu318Lys variant.
Invitae tests that include this gene:
The MITF gene encodes a transcription factor involved in the development, survival, and function of certain cell types, including neural crest-derived melanocytes and optic cup-derived retinal pigment epithelial cells.
MedGen UID: 463554
Malignant melanoma is a neoplasm of melanocytes, the cells that produce pigment. Melanoma most often occurs in the skin, but may also affect the eyes, ears, gastrointestinal tract, and oral and genital membranes. Cutaneous melanoma is considered the most lethal skin cancer if not detected and treated during its early stages (PMID: 26892650). Approximately 5-10% of cases are familial (PMID: 26488006). The c.952G>A (p.Glu318Lys) variant in MITF, also known as E318K, is associated with an increased risk of melanoma (PMID: 26488006, 26650189, 26892651, 22012259, 23167872, 22080950, 25803691). The risks are not yet established; however, studies suggest the risk may be 3- to 5-fold higher than the general population risk (PMID: 22012259, 23167872). This variant has been associated with features including high nevi count (>200), fair skin, non-blue eye color, and early-onset melanoma (under age 40) (PMID: 26488006, 26650189, 26892651, 23774529). Additionally, there is evidence to suggest this variant may predispose to fast-growing melanomas (PMID: 26650189).
Studies showed an overrepresentation of renal cell carcinoma in individuals with this variant (PMID: 22012259, 23167872, 26488006, 26892651, 26650189 ); however, the studies were performed on relatively small patient populations and these findings have not been independently replicated. Therefore, the risk for renal cancer in individuals with the MITF E318K variant is currently unknown.
Other pathogenic variants in the MITF gene are associated with autosomal dominant Waardenburg syndrome (MedGen UID: 349786) and Tietz albinism-deafness syndrome (MedGen UID: 98213) but are currently not analyzed by Invitae.
The MITF gene encodes a transcription factor involved in cell cycle control and melanogenesis. These functions allow MITF to mediate differentiation and survival of melanocytes while limiting their uncontrolled progression (PMID: 25431349).
Hereditary predisposition to cancer due to the MITF E318K variant has autosomal dominant inheritance. This means that an individual with this variant has a 50% chance of passing it on to their offspring. Once such a variant is detected, it is possible to identify at-risk relatives who can pursue testing. Many cases are inherited from a parent, but some cases can occur spontaneously (i.e., an individual with a pathogenic variant has parents who do not have it).
While there are no established screening or surveillance guidelines for individuals with the pathogenic E318K variant in MITF, the following recommendations have been suggested (PMID: 26650189, 26892650):
While there remains lack of a clear consensus on dermatologic management and surveillance guidelines for individuals at increased risk for melanoma, heightened screening may result in early detection and removal of cutaneous lesions at premalignant or early stages, associated with a more favorable prognosis (PMID: 25431349).
An individual’s cancer risk and medical management are not determined by genetic test results alone. Overall cancer risk assessment incorporates additional factors, including personal medical history, family history, and any available genetic information that may result in a personalized plan for cancer prevention and surveillance.
Even though data regarding MITF is preliminary, knowing if a pathogenic variant is present is advantageous. At-risk relatives can be identified, enabling pursuit of a diagnostic evaluation.Further, the available information regarding hereditary cancer susceptibility genes is constantly evolving and more clinically relevant data regarding MITF are likely to become available in the near future. Awareness of this cancer predisposition encourages patients and their providers to inform at-risk family members, to consider implementing proposed screening protocols, and to be vigilant in maintaining close and regular contact with their local genetics clinic in anticipation of new information.
Review Date: March 2016
Invitae is a College of American Pathologists (CAP)-accredited and Clinical Laboratory Improvement Amendments (CLIA)-certified clinical diagnostic laboratory performing full-gene sequencing and deletion/duplication analysis using next-generation sequencing technology (NGS).
Our sequence analysis covers clinically important regions of each gene, including coding exons, +/- 10 base pairs of adjacent intronic sequence, and select noncoding variants. Our assay provides a Q30 quality-adjusted mean coverage depth of 350x (50x minimum, or supplemented with additional analysis). Variants classified as pathogenic or likely pathogenic are confirmed with orthogonal methods, except individual variants that have high quality scores and previously validated in at least ten unrelated samples.
Our analysis detects most intragenic deletions and duplications at single exon resolution. However, in rare situations, single-exon copy number events may not be analyzed due to inherent sequence properties or isolated reduction in data quality. If you are requesting the detection of a specific single-exon copy number variation, please contact Client Services before placing your order.
|Gene||Transcript reference||Sequencing analysis||Deletion/Duplication analysis|
*MITF: Analysis is limited to the NM_000248.3:c.952G>A p.Glu318Lys variant.