Table 1.

Comparison of STR-PCR with Standard PCR and PCR-Southern Blot in the Analysis of SCA2 Patients

Range of expansion	Genotypes (CAG)	N	Standard PCR	PCR- Southern	STR- PCR
Normal	22/22	25	+	n.d.	+
	22/23	4	+	n.d.	+
	22/25	1	+	n.d.	+
	22/27	1	+	n.d.	+
	22/29	1	+	n.d.	+
	22/32	1	+	n.d.	+*
	22/34	1	+	n.d.	+*
Common
mutations	22/37	1	+	n.d.	+*
	22/38	1	+	n.d.	+*
	22/39	2	+	n.d.	+*
	22/40	1	+	n.d.	+*
	22/41	1	+	n.d.	+*
	22/45	1	+	n.d.	+
	22/47	1	+	n.d.	+
	22/49	2	+	n.d.	+
	22/52	1	±	n.d.	+
	22/53	1	±	n.d.	+
Rare large
mutations	23/∼200	1	−	+	+
	22/∼350	1	−	+	+

^*The fluorescent STR-primed PCR could not correctly classify the profile in the normal or expanded range. 

PCR results on the three right columns refer to the larger allele. + and − indicate the ability of a technique to identify an expansion. When ± is present, the expansion was not always detected. 

N, number of tested subjects. n.d., not done.