A Chinese family affected by lynch syndrome caused by MLH1 mutation

BMC Medical Genetics

Table 2 Detection of microsatellite instability

Patient		Proband III7	Proband’s Sister III5	Proband’s Brother III6
MSI status		MSI-H	MSI-H	MSI-H
Genetic testing for microsatellite instability	BAT-25	MSI	MSI	MSI
	BAT-26	MSS	MSI	MSI
	NR-21	MSI	MSI	MSI
	NR-24	MSI	MSI	MSI
	Mono-27	MSS	MSI	MSI
Immunohistochemistry of MMR proteins	MLH1	–	–	–
	MSH2	+	+	–
	MSH6	+	+	–
	PMS2	–	–	+

Microsatellite instability was accessed at both protein and genetic levels. Immunohistochemistry of MMR proteins (MLH1, MSH2, MSH6 and PMS2) was performed to demonstrate the deficiency of MMR system in affected individuals. “-” suggests the deficiency of corresponding proteins and “+” suggests a normal expression of corresponding proteins. Deficiency in MMRs results in MSI
Genetic screening for MSI was performed using the BAT-25, BAT-26, NR-21, NR-25, and Mono-27 markers. MSS microsatellite stable, MSI microsatellite instability, when none of the five markers showed instability. MSI-H MSI-high, when two or more of the five markers showed instability. MSI-L MSI-low, when only one of the five markers showed instability

ISSN: 1471-2350