Table 2.

Variant Exon Statistics

	Constitutive exons			Cryptic internal exons			Cryptic initial/terminal exons
Alternative SSa	Total	EST hit	Confirmed	Total	EST hit	Confirmed	Total	EST hit	Confirmed
None	46,107	24,265 (52.6%)	22,180 (91.4%)	3523	1417 (40.2%)	118 (8.3%)	2779	586 (21.1%)	151 (25.8%)
5′	1,237	668 (54%)	151 (22.6%)	70	42 (60%)	3 (7.1%)	90	51 (56.7%)	7 (13.7%)
3′	1,522	928 (61%)	225 (24.2%)	106	59 (55.7%)	3 (5.1%)	56	27 (48.2%)	4 (14.8%)
5′ and 3′	33	19 (56.7%)	2 (10.5%)	9	7 (77.8%)	0 (0%)	2	2 (100%)	0 (0%)

dbEST sequences were searched for the presence of the variant exon forms that were identified from cDNA sequences. An exon identified from cDNA sequences was considered to have an EST hit when at least one EST from dbEST contained some form of that exon. If all the variant forms were present in the EST data, the exon was considered “confirmed”

^aSS = splice site