Multiple endocrine neoplasia type 2 includes subtypes A and B (MEN2A and MEN2B) and familial medullary thyroid carcinoma (FMTC); all are autosomal dominant disorders characterized by mutations in the RET gene.  All three of the subtypes comprising MEN2 are associated with a high risk for developing medullary carcinoma of the thyroid (MTC), although at distinct age ranges.  MEN2A (OMIM 171400) and MEN2B (OMIM 162300) have an increased risk for pheochromocytoma and MEN2A has an increased risk for parathyroid hyperplasia or adenoma.  MEN2B patients may also present with neuromas of the lips and tongue and a Marfanoid habitus; this phenotype may be apparent in infants as may the associated MTC.  Approximately 75% of patients with MEN2 have the MEN2A subtype.  The diagnosis is based on clinical evaluation and family history.

Known genetic causes of this disorder are mutations in the ret proto-oncogene, RET.  Mutations in RET account for 98%, 98% and 95% of individuals with MEN2A, MEN2B, and FMTC, respectively.  De novo mutations occur in approximately 50% of MEN2B cases (however, the hotspot mutation is the same as with inherited cases, so the tiered strategy presented below remains valid).  Recurrent point mutations have been describe, thus a tiered approach to testing based on clinical finding and/or family history will be used and is outlined below.

Reasons for Referral:

  • Individuals presenting with clinical features of MEN2A
  • Individuals with MTC and clinical diagnosis of MEN2 or primary C-cell hyperplasia.
  • Individuals presenting with adrenal pheochromocytoma.
  • Individuals presenting with clinical features suspicious for MEN2B.
  • Predictive testing for at risk asymptomatic family members.
  • Individuals with Hirschsprung disease.
  • Methodology:

    We sequence exons and exon/intron boundaries of exons 10, 11, 13, 14, 15 and 16 of RET

    Sequencing using either Sanger Sequencing or Next-Generation Sequencing.

    Sanger Sequencing:  Sequencing of RET is carried out by amplification of the above mentioned exons and intron/exon boundaries followed by bi-directional Sanger sequencing.  The sensitivity of full gene sequencing is estimated to be approximately 99% for single nucleotide substitutions and small insertions/deletions.  All nucleotide changes are analyzed within the context of current databases and literature to predict pathogenicity.

    NGS:  Next generation sequencing will analyze the exons or coding regions of RET using Illumina NextSeq 500/550 technology.  Samples are prepared using hybridization probes to enrich exonic regions.  This assay does not assess regions of insufficient coverage, introns and promoter regions; pseudogenes; where the reference genome is inaccurate or contains gaps and insertions; and regions of high GC or polynucleotide repeats, but may contain variants that impact gene function.

    Exon-level deletion/duplication analysis is performed by running the NGS data through the Genome Analysis Toolkit (GATK) Germline Copy Number Variation best practices pipeline from GATK, version A Bayesian model was validated clinically in our lab. The model can detect copy changes at a resolution of three (3) or more probe targets (exons) for deletions and duplications in genes that do not have pseudogenes, and is not designed to detect low-level mosaicism or balanced alterations.

    Specimen Requirements:

    Blood:  EDTA (purple-top) or ACD (yellow-top Solution A or B) tube

    • Adult: 5 mL
    • Child: 5 mL
    • Infant: 2 - 3 mL

    Saliva: 2 ORAgene™ Saliva Collection Kits (OGR-500) used according to manufacturer instructions.  Please contact KDL Client Services for a Saliva Collection Kit for patients that cannot provide a blood sample.

    Assisted Saliva: 4 ORAgene™ Assisted Saliva Collection Kits (OGR-575) used according to manufacturer instructions.  Please contact KDL Client Services for an Assisted Saliva Collection Kit for patients that cannot provide a blood sample.

    Skin Fibroblast: Punch Biopsy (Cell cultures will be prepared at KDL and used for testing), or 2 T-25 confluent flasks.

    DNA: 5-10µg at a minimum of 60-100ng/µL (DNA must be extracted in a CLIA-certified laboratory or a laboratory meeting equivalent requirements as determined by the CAP and/or CMS).


    • Direct Amniotic Fluid (10-20mL)
    • Direct CVS
    • Direct POC
    • Cultured Amniocytes (2 T-25 flasks)
    • Cultured CVS (2 T-25 flasks)
    • Cultured Fetal Tissue: Product of Conception (2 T-25 flasks)
    • Cord Blood (1-2mL)
    Notice Regarding Molecular Genetic Testing on CVS or Amniotic Fluid Specimens:

    Maternal cell rule-out testing will be performed on all prenatal specimens received. Please provide maternal blood (or saliva) in addition to the fetal specimen. Additional charges apply for the maternal cell rule-out test.

    For routine testing of blood and saliva (or DNA extracted from them), KDL does NOT accept samples from patients within two (2) weeks of a packed cell/platelet transfusion or within four (4) weeks of a whole blood transfusion.  For extraordinary circumstances, where testing must be performed outside of the above windows, please contact our lab.

    A REQUISITION FORM MUST ACCOMPANY ALL SAMPLES.  Please include detailed clinical information, including ethnicity, clinical history, and family history.

    Test Performed (Days):


    Turn Around Time:

    14-21 Days

    Shipment Sensitivity Requirements:

    • Package and ship specimen to remain cold, but not frozen.  
    • Ship via overnight express, using the FedEx priority overnight label provided. 
    • Contact Client Services for shipping kits and instructions at (855) 535-1522.


    Additional Info:

    Prior to any genetic testing we recommend genetic counseling.  To receive forms and information about prenatal diagnostic testing, please contact Client Services at (855) 535-1522.

    The Knight Cancer Institute at Oregon Health & Science University is a pioneer in the field of precision cancer medicine. The institute's director, Brian Druker, M.D., helped prove it was possible to shut down just the cells that enable cancer to grow. This breakthrough has made once-fatal forms of the disease manageable and transformed how cancer is treated. The OHSU Knight Cancer Institute is the only National Cancer Institute-designated Cancer Center between Sacramento and Seattle – an honor earned only by the nation's top cancer centers. It is headquarters for one of the National Cancer Institute's largest research collaboratives, SWOG, in addition to offering the latest treatments and technologies as well as hundreds of research studies and clinical trials.

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