Table 1.

Baseline characteristics, exons targeted by PCR primers, and predicted amplicon sizes

	Age at enrolment (years)	DMD deletion	Mobility	Steroids	Age at first biopsy (years)	Dystrophin-positive fibres in original biopsy	MRI grading of EDB muscle	EDB fibrosis		Time between injection and EDB biopsy (weeks)	PCR primers to exons	Amplicon sizes (bp)
								Saline injected	Treated
Low dose
1	16	14 bp deletion in intron 49 that included the exon 50 acceptor splice site	Wheelchair for 11 years	N	8	A few revertant fibres, (∼1–2%); traces on a few fibres	2a	++	++	3	48 and 52	519–286
2	13	Exon 50	Wheelchair for 10 years; rides static bike for 10 min daily	N	7	No revertant fibres; no traces	∞ 2b/3	+++	+++	4	48 and 52	519–286
High dose
3	11	Exons 48–50	Wheelchair for 10 years	Y	7	No revertant fibres; no traces	∞ 2b/3	+++	++	4	46 and 52	570–337
4	15	Exons 48–50	Walks indoors	Y	3	One revertant fibre; traces on many fibres	∞ 2a/2b	+	+	4	46 and 52	570–337
5	11	Exons 45–50	Walks unaided	Y	7	No revertant fibres; traces on a few fibres	1	++	++	4	43 and52	486–253
6	12	Exons 45–50	Walks unaided	Y	3	No revertant fibres; traces on many fibres	2a	++	++	4	43 and 52	486–253
7	10	Exons 49–50	Walks unaided	Y	4	No revertant fibres; traces on many fibres	1	+	+	3	47 and 52	539–306

Numbers are patient number. EDB=extensor digitorum brevis. bp=base pair. Y=yes. N=no. ∞=Asymmetrical EDB involvement on muscle MRI grading. +=Moderate increase of perimysial and endomysial connective tissue; some areas had a severe increase in perimysial and endomysial connective tissue. ++=Most fibres were surrounded by large amounts of connective tissue, but some areas had less and were compact. +++=All fibres surrounded by connective tissue; severe fibrosis throughout sample. EDB=extensor digitorum brevis. bp=base pairs. PCR=polymerase chain reaction