(Present study, 2019) Sri Lanka | (Nadeau et al., 2009) United Kingdom [9] | (Bozorgmehr et al., 2013) Iran [10] | (Martoni et al., 2013) Italy [11] | (Park et al., 2014) Korea [12] | (Brinas et al., 2010) France [13] | (Pace et al., 2008) Australia [14] | (Nalini et al., 2009) India [15] | |
---|---|---|---|---|---|---|---|---|
Gender | Male:Female 0:2 | not recorded | Male: Female 5:1 | Male:Female 2:0 | Male:Female 0:1 | Male: Female 24:25 | Male: Female 6:2 | Male: Female 8:1 |
Parental consanguinity | + (2/2) | + (3/13) | + (6/6) | – | not recorded | + (7/49) | not recorded | + (7/9) |
Clinical history / symptoms | ||||||||
Prenatal reduction of fetal movements | – | not recorded | + (2/6) | not recorded | – | not recorded | not recorded | not recorded |
Congenital contractures | – | not recorded | + (3/6) | not recorded | + | + (2/49) | + (3/8) | + (8/9) |
Difficulty in walking independently | + (2/2) | + (4/13) | + (6/6) | + | + | + (46/49) | + (8/8) | + (9/9) |
Delayed motor milestones | + (2/2) | + (11/13) | + (6/6) | + | + | + (49/49) | + (8/8) | + (9/9) |
Progressive increase in muscle weakness | + (2/2) | + (13/13) | + (6/6) | + | + | + (26/49) | + (8/8) | + (9/9) |
Clinical examination | ||||||||
Abnormal facies | – | not recorded | not recorded | not recorded | not recorded | not recorded | not recorded | + (7/9) |
Joint contractures | – | + (11/13) | + (2/6) | + | + | + (49/49) | + (7/8) | + (9/9) |
Bilateral proximal muscle weakness | + (2/2) | + (13/13) | + (6/6) | + | + | + (49/49) | + (8/8) | + (9/9) |
Gait abnormality/ inability to walk independently | + (2/2) | + (4/13) | + (6/6) | + | + | + (46/49) | + (8/8) | + (9/9) |
Spinal rigidity/scoliosis | – | + (12/13) | + (6/6) | – | + | + (43/49) | + (5/6) | + (7/9) |
Hyperlaxity of distal joints | + (2/2) | not recorded | + (1/6) | + | + | + (49/49) | + (8/8) | + (9/9) |
Absent/indistinguishable palmar creases/soft velvet palms | + (2/2) | not recorded | not recorded | not recorded | + | not recorded | not recorded | + (9/9) |
Atrophy of limbs with or without fasciculation | + (2/2) | not recorded | not recorded | not recorded | + | not recorded | not recorded | + distal muscles mainly |
Keloid formation | – | + (3/13) | not recorded | not recorded | + | not recorded | + (2/8) | not recorded |
Normal intelligence | + (2/2) | + (13/13) | + (6/6) | not recorded | + | not recorded | not recorded | + (9/9) |
Respiratory function abnormality | – | + (13/13) | + (1/6) | – | + | + (35/49) | + (3/8) | + (2/9) |
Follicular hyperkeratosis | – | + (8/13) | + (1/6) | not recorded | not recorded | + (22/49) | + (7/8) | not recorded |
Investigation findings | ||||||||
EMG - short polyphasic motor unit action potentials | + (1/2) | not recorded | + (6/6) | not recorded | Both short and long polyphasic action potentials | not recorded | not recorded | not recorded |
Muscle biopsy - infiltration of adipose tissue, atrophic muscle fibers, angulated fibers | not recorded | not recorded | not recorded | not recorded | + | + (49/49) | + (7/8) | abnormal (9/9) |
Normal or mildly elevated CPK levels (normal 0–200 U/L) | Normal (1/2) mild elevation (1/2) | Ranged from normal to three times upper limit | Mild elevation (1/6) | Normal | Normal | Normal to four times upper limit | Normal (1/8) Mild to three times upper limit (7/8) | Normal (7/9) Mild elevation (2/9) |
Genetic variants involving COL6A1 gene | Homozygous missense variant (c.1667G > T|p.Gly556Val) | Heterozygous missense variants (c.841G > A, c.850G > A) in exon 9 and (c.868G > A) in exon 10 | homozygous missense variant in exon 19 | Heterozygous missense variant (intron 32c.2250 + 1 and exon 33 c.2331 Ins/Dup GCCT) | Heterozygous missense variant (c.904G > A| p.Gly302Arg); homozygous silent variant (c.1095 T > C| p.Gly365=); homozygous intronic variant (c.588 + 19dupC) | Homozygous and heterozygous COL6A1 exon 10 mutations (majority were missense variants) | Missense variant (G > T or G > A) | Possible heterozygous variant in COL6 gene |