TABLE 4.

Types and locations of spontaneous mutations in the hprt gene of Brca2-deficient V-C8 cells

Mutation type	Mutant	Positiona	Exon	Base change	Sequence change	Amino acid
Transversion	SP-17	617	9	GC→TA	ATTT(G)TGTC	Val→Phe
Double mutation	SP-7	530	7	AT→GC	CCAG(A)CTTT	Asp→Gly
		531	7	CG→AT	CAGA(C)TTTG	Asp→Glu
Insertion	SP-23	438–441	6	Insertion of 21 bp
Frameshift	SP-5	156	3	Del. of 1 bp	GAGA(T)GTCA
Deletion	SP-21	137	3	Del. of 8 bp
	SP-11	Del. ex. 2	Del. ex. 2
	SP-12	Del. ex. 4	Del. ex. 4
	SP-14	Del. ex. 4	Del. ex. 4
	SP-20	Del. ex. 2, 3, and 4	Del. ex. 2, 3, and 4
	SP-2	No cDNA	Del. of entire gene
	SP-8	No cDNA	Del. of entire gene
	SP-13	No cDNA	Del. of entire gene
	SP-15	No cDNA	Del. of entire gene
	SP-16	No cDNA	Del. of entire gene
	SP-19	No cDNA	Del. of entire gene
Other	SP-3	No cDNA	All ex. present
	SP-10	No cDNA	All ex. present
	SP-22	No cDNA	All ex. present
	SP-24	No cDNA	All ex. present
	SP-25	Del. ex. 7	Splice
	SP-18	No mutation found

^aDel., deletion; ex., exon(s).