Lynch syndrome        

 

GeneReviews

Lynch syndrome, often called hereditary nonpolyposis colorectal cancer (HNPCC), is a type of inherited cancer of the digestive tract, particularly the colon and rectum. People with Lynch syndrome have an increased risk of cancers of the stomach, small intestine, liver, gallbladder ducts, upper urinary tract, brain, skin, and prostate. Women with this disorder also have a high risk of cancer of the endometrium and ovaries. Hereditary nonpolyposis colorectal cancer (HNPCC) is divided into Lynch syndrome I (familial colon cancer) and Lynch syndrome II (HNPCC associated with other cancers of the gastrointestinal [GI] or reproductive system).

Variations in the MLH1, MSH2, MSH6, PMS2 and EPCAM genes increase the risk of developing Lynch syndrome. All of these genes are involved in the repair of mistakes made when DNA is copied  in preparation for cell division. Mutations in any of these genes prevent the proper repair of DNA replication mistakes. As the abnormal cells continue to divide, the accumulated mistakes can lead to uncontrolled cell growth and possibly cancer. Abnormalities in these genes predispose individuals to cancer, but not all people who carry these mutations develop cancerous tumors. The following criteria can help in determining if a patient should consider gene testing for Lynch syndrome.

Personal history of:

  • Colorectal or endometrial cancer before age 50
  • Abnormal tumor test results (colorectal/endometrial)
  • Two or more Lynch syndrome cancers** at any age
  • A Lynch syndrome cancer** with one or more relatives also with a Lynch syndrome cancer**
  • A previously identified Lynch syndrome or MAP syndrome mutation in the family

Family histories:

  • A first or second degree relative with colorectal or endometrial cancer before the age of 50
  • Two or more relatives with a Lynch syndrome cancer** before the age of 50
  • Three or more relatives with a Lynch syndrome cancer** at any age
  • A previously identified Lynch syndrome or MAP syndrome mutation in the family

We provide testing for genes associated with Lynch syndrome and hereditary colon cancer disorders.

APC, BMPR1A, CDH1, MLH1, MSH2, MSH6, MUTYH, PTEN, SMAD4, STK11, EPCAM and PMS2.

Type OMIM Gene Description

 

HNPCC1

 

 

120435

 

MSH2 Frequency of familial mutations 60%

HNPCC2

609310

MLH1

Frequency of familial mutations 30%

HNPCC5 614350 MSH6

Frequency of familial mutation 7-10%

HNPCC8

613244

EPCAM

Deletions in this gene cause silencing of the MSH2 gene which leads to a clinical presentation similar to Lynch syndrome.

 

HNPCC4

 

614337

PMS2

Mutations in this gene reported in 2% of families with Lynch syndrome. Some mutations an cause a variant of Lynch syndrome called Turcot syndrome.

Purpose: Confirm a genetic basis for cancer/Identify at-risk family members

Methodology: Next-Generation Sequencing

Test Requisition: Sequencing Requisition

Specimen Requirements: 2-5 mL Blood-Lavender Top Tube

Panel CPT Codes: 81435 Cost: $3500.00 (Oklahoma Medicaid requires preauthorization for this test)

Provider can also select specific genes to be analyzed, this will affect pricing and CPT codes used for insurance filing.

Sequencing of known familial mutation Cost: $400.00

Turn-around-time: 6 weeks

Shipping Information

References

1. Kastrinos F, Mukherjee B, Tayob N, et al. (2009). "Risk of pancreatic cancer in families with Lynch syndrome". JAMA 302 (16): 1790–5

2. Bellizzi AM, Frankel WL (2009). "Colorectal cancer due to deficiency in DNA mismatch repair function: a review". Advances in Anatomic Pathology 16 (6): 405–417.

3. Munoz JC, LamHereditary Colorectal Cancer Background. From Medscape. By Juan Carlos Munoz and Louis R Lambiase. Updated: Oct 31, 2011

4. Fishel R, Lescoe M, Rao M, Copeland N, Jenkins N, Garber J, Kane M, Kolodner R (1993). "The human mutator gene homolog MSH2 and its association with hereditary nonpolyposis colon cancer". Cell 75 (5): 1027–38.

5. Miyaki M, Konishi M, Tanaka K, Kikuchi-Yanoshita R, Muraoka M, Yasuno M, et al. (1997). "Germline mutation of MSH6 as the cause of hereditary nonpolyposis colorectal cancer". Nature genetics 17 (3): 271–2.

6. Bronner C. E., Baker S. M., Morrison P. T., Warren G., Smith L. G., Lescoe M. K., et al. (1994). "Mutation in the DNA mismatch repair gene homologue hMLH1 is associated with hereditary non-polyposis colon cancer". Nature 368: 258-261.

7. Kuiper, R. P., Vissers, L. E. L. M., Venkatachalam, R., Bodmer, D., Hoenselaar, E., et al. (2011). "Recurrence and variability of germline EPCAM deletions in Lynch syndrome". Hum. Mutat. 32: 407-414.

8. Mu, W, et al. "Sanger confirmation is required to achieve optimal sensitivity and specificity in next-generation sequencing panel testing". J Mol Diagn. 2016. 18(6):923-932.

 


 

 



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University of Oklahoma Health Sciences Center
1122 NE 13 Street, Suite 1400, Oklahoma City, OK 73104
Phone: (405) 271-3589 |Fax: (405) 271-7117

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