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Scientific Articles

Identification of Duchenne/Becker Muscular Dystrophy Mosaic Carriers Through a Combined DNA/RNA Analysis

key information

source: Prenatal Diagnosis

year: 2018

authors: Zampatti S, Mela J, Peconi C, Pagliaroli G, Carboni S, Barrano G, Zito I, Cascella R, Marella G, Milano F, Arcangeli M, Caltagirone C, Novelli A, Giardina E

summary/abstract:

Objective

The Duchenne/Becker muscular dystrophy (DMD) carrier screening includes the evaluation of mutations in DMD gene, and the most widely used analysis is the multiplex ligation‐dependent probe amplification (MLPA) for the DMD deletions/duplications detection. The high frequency of de novo mutations permits to estimate a risk up to 20% of mosaicisms for mothers of sporadic DMD children. The purpose of this study is to evaluate alternative analytical strategy for the detection of mosaics carrier women, in order to improve the recurrence risk estimation.

Method

Different DNA and RNA analyses were conducted on samples from a woman that conceived a DMD fetus without previous family history of dystrophynopathy.

Results

Standard MLPA analysis failed to identify mosaicism, even if MLPA doses suggested it. Electrophoresis and direct sequencing conducted on RNA permitted to detect two different amplicons of cDNAs, demonstrating the presence of somatic mosaicism. Subsequent detection of a second affected fetus confirmed the mosaic status on the mother.

Conclusion

The implementation of RNA analysis in diagnostic algorithm can increase the sensitivity of carrier test for mothers of sporadic affected patients, permitting detection of mosaic status. A revision of analytical guidelines is needed in order to improve the recurrence risk estimation and support prenatal genetic counseling.

organization: IRCCS Santa Lucia Foundation, Italy; UOSD Medical Genetics, Italy; University of Rome 'Tor Vergata', Italy; Catholic University Our Lady of Good Counsel, Albania; University of L'Aquila, Italy; Bambino Gesù Pediatric Hospital, Italy

DOI: 10.1002/pd.5369

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