J Korean Child Neurol Soc.
2000 Dec;8(2):211-220.
Diagnosis of Duchenne/Becker Muscular Dystrophy: Clinical and Moleculargenetic Characteristics
- Affiliations
-
- 1Department of Pediatrics, Seoul National University College of Medicine, Seoul, Korea.
- 2Department of Clinical Pathology, Seoul National University College of Medicine, Seoul, Korea.
- 3Department of Pathology, Seoul National University College of Medicine, Seoul, Korea.
Abstract
- PURPOSE
Duchenne/Becker muscular dystrophy (DMD/BMD) is an X-linked recessive
disease caused by the mutation of dystrophin gene. Since the majority of mutations are
deletions, recent diagnosis is made by the moleculargenetic tools. The authors summarized
the clinical characteristics, and analyzed the moleculargenetic and immunohistochemical
characteristics of DMD/BMD.
METHODS
We reviewed the clinical and laboratory findings of 69 patients diagnosed
as DMD/BMD from 1989 to 2000. Multiplex PCR using 26 primer sets was performed on
34 cases, and immunohistochemical staining using dystrophin antibody was done on 5
cases. Mutation profile and phenotype-genotype relationship were analyzed.
RESULTS
1) Mean age of onset was 3 years and 6 months. The presenting symptoms were motor
weakness of the lower extremities, incidentally found elevated hepatic enzyme level,
abnormal gait and motor developmental delay. Forty one percent had history of motor
developmental delay, and most patients showed pseudohypertrophic calf muscles. Mean
serum creatine kinase level was 11,232IU/L, and 44% revealed abnormal electrocardiogram.
2) All of the 63 cases showed typical histological findings of muscular dystrophy. Of
the 5 cases with immunohistochemical staining, 2 showed complete (DYS1, 2 and 3) and
3 showed partial (DYS3) absence pattern.
3) Of the 34 cases on which multiplex PCR was performed, 14 showed deletions, and
11 of them had deletions between exon 44 and 55.
CONCLUSION
Since the deletions were detected in less than 50% of the patients with
multiplex PCR, tools for dystrophin protein expression must be combined for the correct
diagnosis. Considering the invasiveness of muscle biopsy, we conclude immunohistochemistry
should be followed in the cases with negative results in multiplex PCR, although
moleculargenetic study is the primary diagnostic tool.