Table 2. C21orf2 mutations in axial SMD.

Family	Mutation
	Nucleotide changea	Amino acid changeb	Location
1	c.643-23A>T	p.N215Vfs*259	Intron 6
5	c.319T>C	p.Y107H	Exon 4
	c.347C>T	p.P116L	Exon 4
6	c.545+1G>A	p.[S183*, A181Qfs*6]c	Intron 5
7	c.643-23A>T	p.N215Vfs*259	Intron 6
8	c.218G>C	p.R73P	Exon 4
9	c.218G>C	p.R73P	Exon 4

^a The nucleotide changes are shown with respect to C21orf2 mRNA sequence (NM_004928).

^b The corresponding predicted amino acid changes are numbered from the initiating methionine residue.

^c There are various minor splicing variants (See Fig 2C).