Table 2.
Patient | Age at last visit | Mutation | Achieved motor milestone | Onset of symptoms | Age at biopsy | Inheritance | CK | Cardial function | Pulmonal function | cMRI |
---|---|---|---|---|---|---|---|---|---|---|
1 (female) | 2 y | Free sitting after being placed at 14 months of age | Reduced child movements during pregnancy. pp: muscular weakness | 2 m | Unknown | 4,000 | Normal | Normal | At 4m of age normal | |
2 (male) | 7 y | Homozygous: c.5134_5153del (leading to a premature stop-codon; p.Arg1712Glufs*4) | Free sitting at 18 months of age, able to scoot on his bottom | At the 3 months of age not able to lift the head and poor head control | 9 m | Recessive | 3,434 | Normal | Normal | Not done |
3 (male) | 6 y | Homozygous: c.7898+2T>G (presumably leading to skipping of exon 56; pathogenicity of an adjacent mutation) (c.7898+1G>T) has already been reported (22) | Free sitting at 10 months of age after being placed | pp: muscular weakness | 14 m | Recessive | 1,584 | Corrected QT interval of 451 m/sec (< 440)ECHO normal | Normal | Leuko-encephalo-pathy |
4 (male) | 4 y | Compound heterozygous: c.397_397delG & c.1884+2T>C | Free sitting at 30 months of age after being placed sitting after being placed | pp: muscular weakness | 4 m | Recessive | 7,400 | Normal | Normal | Leuko-encephalo-pathy |
5 (female) | 3y | Homozygous: c.8244+1G>A(rs749522728); (23) | Walking at 18 months of age with support | At the 4 months of age not able to lift the head and muscular weakness. Rhabdomyolysis at the age of 20 months | 26m | Recessive | 2,7000 | Normal | Normal | Not done |
6 (female) | 2y | Homozygous: deletion of exons 31-40 (diagnosed via MLPA) | Free sitting at 14 months of age after being placed sitting after being placed | At the 3 months of age not able to lift the head and muscular weakness. | 14m | Recessive | 5,200 | Normal | Normal | Leuko-encephalo-pathy |
Y, years; m, month; pp, post-partal; CK, creatine kinase; cMRI, cranial magnetic resonance imaging.