Background
Patients and methods
Study population
Diagnostic criteria
Genetic analysis
Case ascertainment sources
Data analysis
Results
Genetic and other diagnostic standards
Hereditary muscle disease type | Diagnostic criteria |
---|---|
Muscular Dystrophy | |
Myotonic dystrophy types 1 and 2 | Genetic confirmation or, characteristic clinical phenotype + a pathogenic mutation confirmed within the pedigree |
FSHD, LGMD, OPMD, EDMD | Genetic confirmation or, characteristic clinical phenotype + a pathogenic mutation confirmed within the pedigree |
Dystrophinopathies | Genetic confirmation or, |
DMD | characteristic clinical phenotype + absence of dystrophin in Western blot |
CMD | Genetic confirmation or, |
Dystroglycanopathies | characteristic clinical phenotype + muscle biopsy with loss of α-dystroglycan [25] |
Unclassified | characteristic clinical phenotype with onset < 2 years + muscle biopsy with dystrophic pattern |
Metabolic Myopathies | |
Glycogen storage disease | Genetic confirmation or, |
GSD-V | characteristic clinical phenotype + increased serum CK + muscle biopsy with vacuoles with glycogen deposition and absence of myophosphorylase activity [26] |
Unclassified | Characteristic clinical phenotype + increased in serum CK + muscle biopsy with glycogen deposition |
Disorders of glycogen degradation | Genetic confirmation |
Lipid storage disease | Genetic confirmation |
Congenital myopathies | |
Central core | Genetic confirmation or, clinical phenotype + muscle biopsy with cores with devoid of oxidative enzyme activity and type 1 fibre predominance [27] |
Centronuclear | Genetic confirmation or, clinical phenotype + muscle biopsy with central nuclei [28] |
Myosin storage myopathy | Genetic confirmation or, clinical phenotype + muscle biopsy with sarcomeric aggregation of myosin rod filaments [29] |
Nemaline myopathy | Genetic confirmation or, clinical phenotype + muscle biopsy with rod-like structures in muscle fibres [30] |
Fibre type disproportion | Genetic confirmation or, clinical phenotype + muscle biopsy with type 1 fibre diameter at least 35–40% smaller than type 2 fibres diameter in the absence of other structural abnormalities [31] |
Myofibrillar myopathies | Genetic confirmation |
Distal myopathies | Genetic confirmation or, clinical phenotype + myopathic findings on muscle biopsy + myopathic findings on electromyography + magnetic resonance imaging patterns [32] |
Unclassified myopathies | Congenital onset and normal or mildly elevated CK levels or, adult onset proximal weakness + significantly elevated CK and possible recessive inheritance or, myopathy + prominent contractures |
HM Type | Diagnostic standard | N° of cases |
---|---|---|
DM-1 | Genetic confirmation | 225 |
Clinical phenotype + pedigree | 97 | |
FSHD | Genetic confirmation | 32 |
Clinical phenotype + pedigree | 9 | |
LGMD2 | Genetic confirmation | 27 |
Clinical phenotype + pedigree | 4 | |
LGMD2C | Clinical phenotype + muscle biopsy | 2 |
OPMD | Genetic confirmation | 5 |
EDMD | Genetic confirmation | 5 |
DMD | Genetic confirmation | 13 |
Clinical phenotype + muscle biopsy | 2 | |
BMD | Genetic confirmation | 7 |
Dystroglycanopathies | Genetic confirmation | 1 |
Clinical phenotype + pedigree | 1 | |
Clinical phenotype + muscle biopsy | 1 | |
Unclassified CMD | Clinical phenotype + muscle biopsy | 2 |
GSD-II | Genetic confirmation | 2 |
GSD-V | Genetic confirmation | 4 |
Clinical phenotype + muscle biopsy | 2 | |
Unclassified GSD | Clinical phenotype + muscle biopsy | 2 |
Lipid storage disease | Genetic confirmation | 1 |
Central Core | Clinical phenotype + muscle biopsy | 2 |
Myosin storage myopathy | Genetic confirmation | 2 |
Clinical phenotype + muscle biopsy | 1 | |
Nemaline myopathy | Genetic confirmation | 1 |
Clinical phenotype + muscle biopsy | 2 | |
Fibre type disproportion | Clinical phenotype + muscle biopsy | 3 |
Zaspopathy | Genetic confirmation | 4 |
Clinical phenotype + pedigree | 2 | |
Distal myopathies | Clinical phenotype + magnetic resonance imaging patterns | 3 |
Case number | Dystrophinopathy type | Gene | Mutation type | Position and/or sequence variation |
---|---|---|---|---|
1 | DMD | DMD | Deletion | Exons 44–55 |
2 | DMD | DMD | Deletion | Exons 18–28 |
3 | DMD | DMD | Duplication | Exons 18–48 |
4 | DMD | DMD | Deletion | Exons 49 y 50 |
5 | DMD | DMD | Deletion | Exons 45–53 |
6 | DMD | DMD | Deletion | Exons 45–49 |
7 | DMD | DMD | Duplication | Exon 3 |
8 | DMD | DMD | SNV | c.353G > A, p.Trp118a |
9 | DMD | DMD | Deletion | Exon 43 |
10 | DMD | DMD | Deletion | Exons 44–50 |
11a | DMD | |||
12a | DMD | |||
13b | DMD | |||
14 | BMD | DMD | Deletion | Exon 52 |
15 | BMD | DMD | Deletion | Intron 49 |
16 | BMD | DMD | Deletion | Exons 3–7 |
17 | BMD | DMD | Deletion | Exons 45–55 |
18 | BMD | DMD | Duplication | Exon 2 |
19b | BMD | |||
20b | BMD |
Muscular disease type | Gene | Mutation type | Sequence variation | Position | Zygosity | Cases, n | Families, n |
---|---|---|---|---|---|---|---|
Muscular dystrophy | |||||||
MD1 | DMPK | Expanded CTG (> 40) | 3′-UTR | 225 | 116 | ||
FSHD1 | DUX | Deletion D4Z4 | 25 | 21 | |||
FSHD2 | SMCHD1 | SNV | c.5602C > T | Exon 45 | Het | 6 | 1 |
SMCHD1 | SNV | c.2329A > T | Exon 18 | Het | 1 | 1 | |
LGMD2A | CAPN3 | Frameshift variant | c.2362_2363delinsAG/TCATCT | Exon 22 | Hom | 16 | 15 |
CAPN3 CAPN3 | SNV Frameshift variant | c.664G > A c.2362_2363delinsAG/TCATCT | Exon 5 Exon 22 | Het Het | 1 | 1 | |
LGMD2B | DYSF | SNV | c.895G > A | Exon 9 | Hom | 1 | 1 |
LGMD2C | SGCG | SNV | c.848G > A | Exon 8 | Hom | 2 | 2 |
LGMD2D | SGCA | SNV | c.293G > A | Exon 3 | Hom | 1 | 1 |
LGMD2I | FKRP | SNV | c.826C > A | Exon 4 | Hom | 1 | 1 |
LGMD2L | ANO5 | Frameshift variant | c.1627dupA | Exon 15 | Hom | 1 | 1 |
ANO5 | Frameshift variant | c.191dupA | Exon 5 | Hom | 2 | 1 | |
ANO5 ANO5 | Frameshift variant SNV | c.191dupA c.1664G > T | Exon 5 Exon 16 | Het Het | 1 | 1 | |
ANO5 ANO5 | SNV Splice variant | c.172C > T c.1119 + 1G > T | Exon 4 Intron 12 | Het Het | 1 | 1 | |
OPMD | PABPN1 | Expanded GCN (> 10) | Exon 1 | 5 | 4 | ||
Emerin EDMD | EMD | Complete deletion | 1 | 1 | |||
Lamin EDMD | LMNA | SNV | c.1130G > A | Exon 6 | Het | 2 | 1 |
LMNA | SNV | c.215G > T | Exon 1 | Het | 1 | 1 | |
LMNA | SNV | c.65C > A | Exon 1 | Het | 1 | 1 | |
DMC-Dystroglicanopathy | GMPPB | SNV | c.553C > T | Exon 5 | Hom | 1 | 1 |
Metabolic myopathy | |||||||
GSD-II | GAA GAA | Intronic variant SNV | c.-32-13 T > G c.1933G > T | Intron 1 Exon 14 | Het Het | 1 | 1 |
GAA GAA | Intronic variant SNV | c.-32-13 T > G c.1724A > G | Intron 1 Exon 12 | Het Het | 1 | 1 | |
GSD-V | PYGM | Stop gained | c.148C > T | Exon 1 | Hom | 1 | 1 |
PYGM PYGM | Stop gained SNV | c.148C > T c.1468C > T | Exon 1 Exon 12 | Het Het | 1 | 1 | |
PYGMa | 1 | 1 | |||||
PYGMa | 1 | 1 | |||||
Lipid storage disease | CPT2 | SNV SNV | c.359A > G c.1547 T > C | Exon 4 Exon 4 | Het Het | 1 | 1 |
Congenital myopathy | |||||||
Myosin storage | MYH-7 | SNV | c.5533C > T | Exon 37 | Het | 1 | 1 |
MYH-7 | SNV | c.1314G > A | Exon 14 | Het | 1 | 1 | |
Nemaline | ACTA1 | SNV | c.808G > C | Exon 5 | Het | 1 | 1 |
Myofibrillar myopathy | |||||||
Zaspopathy | LDB3 | SNV | c.494C > T | Exon 5 | Het | 4 | 1 |
Prevalence
Type of myopathy | Cases, n | PRx105 (CI 95%) | PR male | PR female | p | Mean age (SD) |
---|---|---|---|---|---|---|
Muscular dystrophy | 312 | 48.70 (43.59–54.41) | 53.80 | 43.67 | 0.066 | 46.43 (17.14) |
Myotonic dystrophy 1 | 230 | 35.90 (31.55–40.85) | 36.18 | 35.63 | 0.906 | 47.06 (15.39) |
FSHD | 33 | 5.15 (3.67–7.23) | 6.92 | 3.41 | 0.052 | 55.51 (14.44) |
FSHD1 | 27 | 4.21 (2.90–6.13) | 5.98 | 2.48 | 0.320 | 58.15 (13.06) |
FSHD2 | 6 | 0.94 (0.43–2.04) | 0.94 | 0.93 | 0.985 | 43.67 (15.54) |
LGMD2 | 27 | 4.21 (0.90–6.13) | 5.03 | 3.41 | 0.325 | 45.04 (17.67) |
LGMD2A | 16 | 2.50 (1.54–4.05) | 2.52 | 2.48 | 0.975 | 43.81 (14.63) |
LGMD2B | 1 | 0.16 (0.03–0.88) | 0.31 | 0.00 | 0.496 | 56 (−) |
LGMD2C | 3 | 0.47 (0.16–1.38) | 0.94 | 0.00 | 0.122 | 21.33 (24.45) |
LGMD2D | 1 | 0.16 (0.03–0.88) | 0.00 | 0.31 | 0.503 | 46 (−) |
LGMD2I | 1 | 0.16 (0.03–0.88) | 0.31 | 0.00 | 0.496 | 53 (−) |
LGMD2L | 5 | 0.78 (0.33–1.83) | 0.94 | 0.62 | 0.675 | 59.20 (16.51) |
OPMD | 2 | 0.31 (0.08–1.14) | 0.63 | 0.00 | 0.246 | 72 (15,56) |
EDMD | 5 | 0.78 (0.33–1.83) | 0.94 | 0.62 | 0.675 | 41.80 (19.32) |
Emerin EDMD | 1 | 0.16 (0.03–0.88) | 0.31 | 0.00 | 0.496 | 19 (−) |
Lamin EDMD | 4 | 0.62 (0.24–1.60) | 0.63 | 0.62 | 0.988 | 47.5 (16.76) |
Dystrophinopathy | 11 | 1.71 (0.95–3.07) | 3.46 | 0.00 | 0.000 | 18.73 (18.26) |
DMD | 6 | 0.94 (0.43–2.04) | 1.89 | 0.00 | 0.015 | 8.33 (4.80) |
BMD | 5 | 0.78 (0.33–1.83) | 1.57 | 0.00 | 0.030 | 31.2 (21.18) |
CMD | 4 | 0.62 (0.24–1.60) | 0.63 | 0.62 | 0.988 | 13.25 (6.34) |
Glycosylation disorder | 3 | 0.47 (0.16–1.38) | 0.63 | 0.31 | 0.616 | 10.67 (4.51) |
Unclassified CMD | 1 | 0.16 (0.03–0.88) | 0.00 | 0.31 | 0.503 | 21 (−) |
Metabolic myopathies | 11 | 1.71 (0.95–3.07) | 2.52 | 0.93 | 0.139 | 45.91 (19.13) |
Glycogen storage | 10 | 1.56 (0.85–2.87) | 2.52 | 0.62 | 0.062 | 49.10 (16.80) |
GSD-II | 2 | 0.31 (0.08–1.14) | 0.63 | 0.00 | 0.246 | 43 (12.73) |
GSD-V | 6 | 0.94 (0.43–2.04) | 1.26 | 0.62 | 0.442 | 5.15 (20.83) |
Unclassified | 2 | 0.31 (0.08–1.14) | 0.63 | 0.00 | 0.246 | 48 (9.90) |
Lipid storage disease | 1 | 0.16 (0.03–0.88) | 0.00 | 0.31 | 0.503 | 14 (−) |
Congenital myopathy | 8 | 1.25 (0.63–2.46) | 2.20 | 0.31 | 0.037 | 36.12 (14.20) |
Central Core | 2 | 0.31 (0.08–1.14) | 0.63 | 0.00 | 0.246 | 22.50 (24.75) |
Myosin storage myopathy | 3 | 0.47 (0.16–1.38) | 0.94 | 0.00 | 0.122 | 44.67 (9.07) |
Fibre type disproportion | 3 | 0.47 (0.16–1.38) | 0.63 | 0.31 | 0.616 | 36.67 (4.62) |
Distal myopathy | 3 | 0.47 (0.16–1.38) | 0.63 | 0.31 | 0.616 | 65.67 (17.78) |
Zaspopathy | 5 | 0.78 (0.33–1.83) | 1.26 | 0.31 | 0.212 | 63.40 (4.88) |
Unclassified myopathy | 39 | 6.09 (4.45–8.32) | 6.92 | 5.27 | 0.402 | 59.92 (21.86) |
Total | 378 | 59.00 (53.35–65.26) | 67.33 | 50.80 | 0.006 | 46.93 (17.77) |
Group age | PR/100,000 (CI 95%) | PR/100,000 (CI 95%) by gender | p | |
---|---|---|---|---|
Women | Men | |||
< 15 | 21.87 (14.44–33.11) | 10.20 (4.36–23.87) | 32.97 (20.59–52.80) | 0.015 |
15–24 | 41.84 (28.56–61.30) | 42.84 (25.04–73.29) | 40.89 (23.9–69.95) | 0.906 |
25–34 | 48.99 (35.39–67.82) | 21.93 (11.11–43.27) | 75,68 (52.37–109.40) | 0.000 |
35–44 | 72.13 (57.64–90.26) | 70.53 (50.95–97.62) | 73.63 (54.08–100.24) | 0.853 |
45–54 | 91.32 (74.31–112.2) | 93.36 (69.79–124.92) | 89.37 (66.81–119.6) | 0.836 |
55–64 | 91.50 (72.56–115.40) | 82.69 (58.58–116.7) | 100.27 (73.37–137.20) | 0.421 |
65–74 | 59.40 (42.92–82.23) | 57.51 (36.38–90.9) | 61.43 (38.86–97.09) | 0.844 |
75–84 | 39.08 (24.06–63.47) | 21.42 (9.15–50.14) | 62.48 (34.9–111.90) | 0.044 |
≥85 | 23.38 (9.99–54.73) | 13.92 (3.81–50.76) | 42.73 (14.53–125.62) | 0.245 |
Total | 59.00 (53.35–65.26) | 50.80 (43.46–59.36) | 67.33 (58.9–76.97) | 0.006 |