Detection of a novel dystrophin gene mutation through carrier analysis performed during prenatal diagnosis in a case with intragenic recombination.
OBJECTIVE
To report a multi-technical approach to Duchenne muscular dystrophy (DMD) mutation testing through carrier analysis, in the prenatal diagnosis of a male foetus without a known mutation segregating in the family and with inconclusive results of linkage analysis.


METHODS
Haplotype analysis with the DMD region markers for assigning the carrier status of the mother and for prenatal diagnosis of foetal DNA; semiquantitative multiplex analysis of maternal and foetal DNA for the promoter and for 34 exons of the DMD gene; sequencing analysis of the maternal and foetal DNA for confirmation of the results.


RESULTS
Because of an intragenic recombination of the DMD gene in foetal DNA, haplotype analysis gave inconclusive results. Semiquantitative PCR analysis displayed a pattern compatible with a heterozygous exon 60 mutation in the mother's DNA, while foetal DNA showed a normal migration pattern. Sequencing analysis confirmed the presence of a novel 7 base-pair deletion in exon 60 of the DMD gene in the mother and excluded the deletion in the foetus.


CONCLUSIONS
Semiquantitative PCR results allowed the DMD mutation detection in the mother and the exclusion in the foetus, showing its crucial importance in prenatal diagnosis in those cases where linkage analysis is not conclusive.
Percesepe
Antonio
A
Unità di Genetica Medica, Università di Modena, Italy. percesepe.antonio@unimo.it
Ferrari
Maurizio
M
Coviello
Domenico
D
Zanussi
Monica
M
Castagni
Marina
M
Neri
Isabella
I
Travi
Maurizio
M
Forabosco
Antonino
A
Tedeschi
Silvana
S
D004252:DNA Mutational Analysis; D016189:Dystrophin / Q000235:genetics*; D005091:Exons; D005260:Female; D005315:Fetal Diseases / Q000175:diagnosis* / Q000235:genetics; D008040:Genetic Linkage; D006239:Haplotypes; D006579:Heterozygote; D006801:Humans; D007231:Infant, Newborn; D008297:Male; D020388:Muscular Dystrophy, Duchenne / Q000175:diagnosis* / Q000235:genetics; D009154:Mutation; D010375:Pedigree; D011247:Pregnancy; D011296:Prenatal Diagnosis / Q000379:methods*; D011995:Recombination, Genetic
D016189:Dystrophin