Table 1. Variants identified in the hMLH1 and hMSH2 genes during this study.

Gene	Family ID	Risk statusa	MSI	Exon	Nucleotide	Effect	Types of cancer
Mutation
hMLH1	3335	Amsterdam	4/5	15	1669G>T b	E557X	CRCc, melanoma, liver, TCCd, endometrium, lung
	5838	Amsterdam	NT	8	676C>T	R226X	CRCc, endometrium, larynx, stomach
hMSH2	7562	Amsterdam	0/5	3	Dele 2.2 kb	Protein missing aa 123–215	CRCc, endometrium
	8344	Bethesda	4/5	3	472C>T b	Q158X	CRCc
	8902	Amsterdam	5/5	13	2131C>T	R711X	CRCc, ovaries, endometrium
	9663	Amsterdam	NT	11	1704_1705dele AGb	Fsf resulting in STOP at codon 570	CRCc, endometrium
	10107	Amsterdam	NT	6	1076G>T b	R359X	CRCc, ovary, endometrium, urinary tract, eye, prostate, melanoma, breast
Gene	Exon	Codon	Nucleotide change	Consequences	No. of families
Benign polymorphisms
hMLH1	IVS 4	309−30 b	c>a	—	2
	Exon 8	219	655A>G	I219V	5
	Exon 12	464 b	464T>C	P464P
	IVS 12	1408−54 b	c>t	—	2
	IVS 13	1558−13	g>a	—	2
	IVS 14	1668−19	a>g		6
hMSH2	IVS 1	211+9	c>g	—	1
	Exon 4	224 b	669C>T	L224L	2
	IVS 9	1511−9	a>t	—	1
	IVS 10	1661+13	g>a	—	2
	IVS 12	2006−6	t>c	—	2

^aRisk status based on the Amsterdam II (Vasen et al, 1999) and Bethesda (Rodrigues – Bigas et al, 1997) criteria.

^bNovel variations identified in this study (marked in bold).

^cCRC=colorectal cancer.

^dTCC=transitional cell carcinoma.

^eDel=deletion.

^fFs=frame shift mutation.