Gastroenterology Diagnostic Services

GenPath employs over 40 board-certified pathologists, including cytopathologists and surgical pathologists with expertise in gastrointestinal pathology. Combining GenPath’s pathology expertise and full-service clinical test menu provides healthcare providers with comprehensive gastroenterology (GI) diagnostic services.

GenPath’s pathology services are led by Liang Liu, MD, PhD.

Advantages of GenPath GI Diagnostic Services

  • Comprehensive test menu
  • GI expertise
  • Extensive insurance coverage
  • Ordering and reporting to meet each practice’s needs
    • EMR interface for HL7 ordering and reporting
    • InsightDx®, online ordering and reporting system
    • Stormpath®, GenPath’s remote pathology software solution
    • Customizable paper requisition
    • Auto-print for finalized reports

Comprehensive Test Menu

  • Comprehensive H. pylori testing: Immunoglobulins (A,G,M), urea breath test, antigen stool, immunohistochemistry, H. pylori detection and clarithromycin resistance detection by Polymerase Chain Reaction (PCR) performed on a stomach biopsy (paraffin block)
    • Molecular methods such as PCR using FFPE samples have been shown to reliably detect the H. pylori 23S rRNA mutation associated with clarithromycin resistance1
  • Fluorescent In-Situ Hybridization (FISH): HER2 amplification for gastric/gastroesophageal carcinoma
  • Histology/Immunohistochemistry (IHC): GenPath offers hundreds of IHC stains that can be applied to any gastrointestinal biopsy, including HER2 for gastric/gastroesophageal carcinoma (with reflex to FISH), mismatch repair protein screening (MLH1, MS2, MSH6, PMS2), H. pylori, markers for tumor of unknown primary, neuroendrocrine carcinomas, lymphomas, and other likely tumors of the GI tract
    • MMR by IHC is useful to detect deficiencies in mismatch repair genes. Stage II colorectal cancer patients with MMR deficient tumors do not respond favorably to chemotherapy. Additionally, metastatic tumors that are MMR deficient may derive benefit from the immunotherapy drug, pembrolizumab. Screening is also an initial test done for Lynch syndrome. Defects in MMR can lead to microsatellite instability-high (MSI-H) syndrome.
  • Molecular testing: Our robust molecular offering includes Microsatellite Instability (MSI), MLH1 Hypermethylation, BRAF V600E, and our OnkoSightTM suite of NGS panels for solid tumors, including colorectal
    • MSI by PCR: Microsatellites are short, tandemly repeated DNA sequences of one to six bases. Microsatellite instability (MSI) can be due to either a change in length of the microsatellite allele or to an insertion/deletion of repeating units during replication, with lack of correction due to a defect in the DNA mismatch repair (MMR) system. MMR germline defects may be present in any of five MMR genes: MLH1, MSH2, MSH6, PMS2, and PMS1; the latter two are uncommon. Somatic hypermethylation of MLH1is also a cause of MMR defects.
    • MLH1hypermethylation: Determination of the methylation status of the MLH1 gene promoter in patients with microsatellite instable (MSI-H) colorectal carcinoma helps in discriminating sporadic from hereditary non-polyposis colon cancer (HNPCC or Lynch syndrome). The hMLH1 gene is located at chromosome 3p21-23 and is part of the DNA mismatch repair system; epigenetic, non-germline methylation of its promoter region is one of the possible mechanisms for transcription silencing. The final result of this aberration, MSI-H phenotype, is functionally similar to the presence of loss-of-function germline mutation in the coding region of the gene, identifiable in patients with HNPCC.
    • OnkoSight Advanced Colorectal Cancer Panel (29 genes): Targeted, tumor-specific gene content with clear therapeutic, diagnostic, or prognostic value and those for which there are late-stage clinical trial options. Relevant information includes Tumor Mutation Burden (TMB) and Microsatellite Instability (MSI) presence for a comprehensive patient workup.
  • Hereditary cancer: Targeted hereditary cancer panel for the most common hereditary colorectal cancer syndromes, such as Lynch syndrome, Familial Adenomatous Polyposis (FAP), and MUTYP-Associated Polyposis (MAP) (MLH1, MSH2, MSH6, PMS2, EPCAM, APC, and MUTYH) are available, as well as a larger panel for hereditary colorectal cancer.
  • Routine clinical: Chemistries, lipids, tumor markers, thyroid testing, immunoglobulins, vitamins, PT and PTT. For a full list of routine clinical tests, please see our Gastroenterology Clinical Test Requisition Form.
  • Comprehensive hepatitis panel: Panels for all viral hepatitis interrogation, including total, surface, and core antibodies, viral loads, genotyping, as well as Hepatitis C Virus (HCV) NS3/ NS5 a/b Panel1 to determine HCV drug resistance in patients who have been diagnosed with HCV. Also offer non-invasive testing for baseline determination of current liver health status to assist in treatment management.
  • Allergy testing: Hundreds of allergy profiles are available, including ImmunoCAP® Allergy Profiles that tests for general food allergy as well as component testing for specific egg, milk, and nut proteins to help determine how likely a patient is to react to baked or raw products; Regional Respiratory Profiles that will help pinpoint specific allergens in a patient’s local area to aid in targeted therapy and will help identify where allergens are prevalent and what that patient should avoid.
  • Gastric distress and gluten insensitivity panel*: Identifies key allergic and autoimmune conditions that may be the cause of unexplained GI symptoms. GenPath offers the Gastric Distress Profile that provides clinical data that can confirm or exclude common disorders and diseases that present with similar symptoms. The Gastric Distress Profile includes markers for gastritis, celiac disease and gluten sensitivity, and food allergies. Benefits of testing include:
    • Identification of underlying symptoms and diseases leading to a specified treatment approach
    • Reducing unnecessary tests, resulting in faster diagnosis
    • Treatment management tools that utilize previous results and highlighted abnormalities on clinical reports
    • Promotion of patient engagement and treatment compliance

*Available for non-NYS clients only.


  1. Thung, I., Aramin, H., Vavinskaya, V., et al. Review article: The global emergence of Helicobacter pylori antibiotic resistance. Ailment Pharmacol Ther 2016; 43: 514-533 DOI: 10.1111/apt.13497.