Prenatal diagnosis of Duchenne muscular dystrophy in the Japanese population by fluorescent CA repeat polymorphisms analysis.
OBJECTIVE
To investigate the efficacy of CA repeat analysis using fluorescence-labeled primers in the prenatal diagnosis of Duchenne muscular dystrophy in the Japanese population.


METHODS
Allelic frequencies of polymorphic loci in the Duchenne muscular dystrophy gene were ascertained, and the polymorphic information content (PIC) was calculated. CA repeat analysis of 21 Japanese families with Duchenne muscular dystrophy was then performed.


RESULTS
The STR 49 locus had the highest PIC, followed in decreasing order by the loci of STR 44, STR 45, STR 50, DYS III, DYS II, DYS I, and 3' CA. The diagnostic applicability increased to 0.999 when the PICs of all 8 loci were combined. When the highest PIC from each of the 5' end, exons near the 3' end and the 3' end were combined, the diagnostic applicability increased to 0.988. Of the 7 males examined prenatally, 1 was diagnosed as normal, and 6 were affected, while of the 9 females examined, 5 were diagnosed as carriers, and 4 as non-carriers.


CONCLUSIONS
CA repeat analysis using fluorescence-labeled primers is useful in the prenatal diagnosis of Duchenne muscular dystrophy in the Japanese population.
Shiroshita
Y
Y
First Department of Obstetrics and Gynecology, School of Medicine, Toho University, Tokyo, Japan.
Katayama
S
S
D000483:Alleles; D004247:DNA / Q000032:analysis* / Q000235:genetics; D016189:Dystrophin / Q000235:genetics*; D005260:Female; D005787:Gene Frequency / Q000235:genetics*; D008040:Genetic Linkage / Q000235:genetics; D006579:Heterozygote; D006801:Humans; D007564:Japan; D007962:Leukocytes / Q000737:chemistry*; D008297:Male; D018895:Microsatellite Repeats / Q000235:genetics; D009136:Muscular Dystrophies / Q000097:blood / Q000175:diagnosis* / Q000235:genetics; D010375:Pedigree; D011110:Polymorphism, Genetic / Q000235:genetics*; D011296:Prenatal Diagnosis / Q000379:methods*
D016189:Dystrophin; D004247:DNA