Table 1

Genotype and phenotype in patients with a subtle mutation of SMN1 gene
Family No. Case No. PhenoType Gender Age at last examination Age of onset Attained motor function SMN1 genotype Point Mutationlocation SMN2 copies Fl-SMN2 transcript Fl-SMN transcript Parental origin
Head control Sit unsupported Walk independently Allele1 Allele2
1 1 I M 3y6m 4 m + - - Deletion p.Ser8LysfsX23 Exon 1 2 - - ND
2 2 II M 1y7m 11 m + + - Deletion p.Ser8LysfsX23 Exon 1 2 6.33 ± 1.72 6.76 ± 1.94 Paternal
3 3 II M 6y8m 1y2m + + - Conversion p.Ser8LysfsX23 Exon 1 3 20.36 ± 11.09 21.01 ± 10.4 Paternal
4 4 II M 5y 11 m + + - Deletion p.Glu134Lys Exon 3 2 7.73 ± 5.44 12.46 ± 5.47 Paternal
5 5 II F 2y6m 1y1m + + - Deletion p.Glu134Lys Exon 3 2 6.41 ± 5.78 11.21 ± 3.45 Paternal
6 6 I F 2y3m 4 m + - - Deletion p.Leu228X Exon 5 2 9.24 ± 6.6 10.277 ± 6.8 Maternal
7 7 II M 4y1m 8 m + + - Conversion p.Leu228X Exon 5 3 - - ND
8 8 II M 14y 10 m + + - Deletion p.Ser230Leu Exon 5 2 8.04 ± 7.27 12.22 ± 7.07 Paternal
9 III F 9y8m 2y + + +† Deletion p.Ser230Leu Exon 5 2 9.35 ± 5.74 14.83 ± 4.45 Paternal
9 10 II M 6y4m 1y + + - Deletion p.Tyr277Cys§ Exon 6 2 4.53 ± 3.47 6.54 ± 4.33 Maternal
10 11# I F 2y10m 5 m + - - Conversion p.Arg288Met Exon 7 3 13.1 ± 10.4 13.71 ± 10.6 Paternal
11 12# II F 4y4m 1y6m + + - Conversion p.Arg288Met Exon 7 3 9.46 ± 7.84 12.46 ± 8.01 Paternal
12 13 II M 5y 10 m + + - Deletion - - 2 8.02 ± 1.97 9.86 ± 2.01 ND
13 14 III M 15y 1y5m + + +† Conversion - - 3 21.67 ± 11.0 25.17 ± 11.8 ND

Conversion means deletion of SMN1 owing to conversion of SMN1 sequences to SMN2 with the copy number of SMN2 increasing. ND, not detected. §Novel mutation; #,these patients had been reported [22]; †, Walk in waddling gait ;case 8 and case 9 are siblings.

Yu-jin et al.

Yu-jin et al. BMC Medical Genetics 2012 13:86   doi:10.1186/1471-2350-13-86

Open Data