|
| |
Limb Girdle Muscular Dystrophies
05 November, 2004
The LGMDs are face-sparing,
proximally predominant, progressive muscular dystrophies with
elevated creatine kinase levels and dystrophic features on muscle
biopsy. In the current classification system, LGMDs are divided into
autosomal dominant (LGMD1) and autosomal recessive (LGMD2) disorders
with a superimposed lettering system denoting the chronologic order
of chromosomal linkage (thus far, A through E for autosomal dominant
and A through J for autosomal recessive LGMDs).
Table Distinguishing features for diagnosis of the limb-girdle
muscular dystrophies
|
Disease
|
Linkage
|
Protein product
|
Age at onset, y
|
Distinctive feature
|
CK level
|
Diagnostic modalities
|
|
Autosomal dominant |
|
|
|
|
|
|
|
LGMD1A |
5q22.3-31.3 |
Myotilin |
20 –40 |
Dysarthria |
NL–10X |
DNA only |
|
LGMD1B |
1q11-21 |
Lamin A/C |
<10 |
Contractures |
NL–20X |
DNA only |
|
LGMD1C |
3p25 |
Caveolin-3 |
<10 |
Mounding/Rippling |
2–25X |
IS, WB |
|
LGMD1D |
6q23 |
Unknown |
15 –50 |
Cardiomyopathy |
NL–4X |
|
|
LGMD1E |
7q |
Unknown |
30 –50 |
No |
NL–10X |
|
|
Autosomal recessive |
|
|
|
|
|
|
|
LGMD2A |
15q15.1 |
Calpain-3 |
5 –40 |
Adductor weakness |
NL–50X |
WB |
|
LGMD2B |
2p13 |
Dysferlin |
10 –30 |
Distal leg weakness |
10–150X |
IS, WB |
|
LGMD2C-F |
13q, 17q, 4q, 5q |
 -,
 -, ß-,
 -sarcoglycan |
3 –20 |
No |
5–120X |
IS, WB |
|
LGMD2G |
17q11-q12 |
Telethonin |
2 –15 |
Brazilian |
2–30X |
IS, WB |
|
LGMD2H |
9q31-q34 |
TRIM32 |
5 –30 |
Hutterite |
NL–20X |
DNA only |
|
LGMD2I |
19q13.3 |
Fukutin related protein |
1 –40 |
Respiratory dysfunction |
5–40X |
DNA only |
|
LGMD2J |
2q31 |
Titin |
5 –20 |
Finns |
NL–2X |
DNA only |
|
|
CK = creatine kinase; NL =
Normal; IS = immunostaining; WB = Western blotting. |
|
|
