[Diagnosis of congenital muscular dystrophy and clinical significance of merosin expression].
OBJECTIVE
The congenital muscular dystrophies (CMD) are a clinically and genetically heterogeneous group of neuromuscular disorders with progressive muscle wasting and weakness that begin during neonatal or early infantile period. To study the clinical diagnosis, immunohistochemical feature and follow-up information of CMD, data of 8 cases with CMD were analyzed.


METHODS
Immunohistochemical features of biopsied muscle specimens were summarized and analyzed by using anti-laminin alpha2 (merosin), anti alpha-dystroglycan (alpha-DG) and anti beta-dystroglycan (beta-DG) antibodies.


RESULTS
These patients mostly presented at birth or during the first six months of life with muscle weakness, hypotonia, contractures, and feeding difficulty or respiratory dysfunction. Hematoxylin-eosin staining of skeletal muscle specimens from these patients showed typical characteristics of CMD. Differences in fiber size, with predominantly small and round fibers, and dense connective tissue infiltration were seen. Four of the 8 patients were merosin-stain negative, which might be due to primary merosin deficiency. T2-weighted magnetic resonance imaging of the brain shows abnormalities of the white matter. Four cases were merosin-stain positive, and two of them also had hypoglycosylation of alpha-dystroglycan. Two patients had mental retardation. One of them had optic nerve atrophy and abnormal brain structure.


CONCLUSIONS
Two types of CMD were present in our group. Merosin-deficient congenital muscular dystrophy (congenital muscular dystrophy 1A, MDC1A) was more common, accompanied by abnormalities of the white matter. "Alpha-dystroglycanopathy" could be seen in merosin-positive cases.
Xiong
Hui
H
Department of Pediatrics, First Hospital, Peking University, Beijing 100034, China.
Yao
Sheng
S
Yuan
Yun
Y
Chang
Xing-zhi
XZ
Wu
Ye
Y
Bao
Xin-hua
XH
Zhang
Yue-hua
YH
Wu
Hu-sheng
HS
Chen
Lin
L
Qin
Jiong
J
Wu
Xi-ru
XR
D005260:Female; D006801:Humans; D007223:Infant; D007797:Laminin / Q000172:deficiency*; D008297:Male; D009136:Muscular Dystrophies / Q000151:congenital* / Q000175:diagnosis* / Q000378:metabolism
D007797:Laminin