Extensive next-generation sequencing approaches for the identification of rare genomic structural variants involving the DMD gene

Rita Selvatici

Extensive next-generation sequencing approaches for the identification of rare genomic structural variants involving the DMD gene

Autori

ALICE MARGUTTI (UNIT OF MEDICAL GENETICS, DEPARTMENT OF MEDICAL SCIENCES AND DEPARTMENT OF MOTHER AND CHILD, UNIVERSITY HOSPITAL S. ANNA FERRARA, FERRARA – MEDICAL GENETICS)
MARTINA MIETTO (UNIT OF MEDICAL GENETICS, DEPARTMENT OF MEDICAL SCIENCES AND DEPARTMENT OF MOTHER AND CHILD, UNIVERSITY HOSPITAL S. ANNA FERRARA, FERRARA – MEDICAL GENETICS)
VITTORIA NAGLIATI (UNIT OF MEDICAL GENETICS, DEPARTMENT OF MEDICAL SCIENCES AND DEPARTMENT OF MOTHER AND CHILD, UNIVERSITY HOSPITAL S. ANNA FERRARA, FERRARA – -)
MARIA SOFIA FALZARANO (UNIT OF MEDICAL GENETICS, DEPARTMENT OF MEDICAL SCIENCES AND DEPARTMENT OF MOTHER AND CHILD, UNIVERSITY HOSPITAL S. ANNA FERRARA, FERRARA – -)
GAETANO DE FEO (UNIT OF MEDICAL GENETICS, DEPARTMENT OF MEDICAL SCIENCES AND DEPARTMENT OF MOTHER AND CHILD, UNIVERSITY HOSPITAL S. ANNA FERRARA, FERRARA – MEDICAL GENETICS)
GIUSY CAVARRETTA (UNIT OF MEDICAL GENETICS, DEPARTMENT OF MEDICAL SCIENCES AND DEPARTMENT OF MOTHER AND CHILD, UNIVERSITY HOSPITAL S. ANNA FERRARA, FERRARA – MEDICAL GENETICS)
FERNANDA FORTUNATO (UNIT OF MEDICAL GENETICS, DEPARTMENT OF MEDICAL SCIENCES AND DEPARTMENT OF MOTHER AND CHILD, UNIVERSITY HOSPITAL S. ANNA FERRARA, FERRARA – MEDICAL GENETICS)
MARCELLA NERI (UNIT OF MEDICAL GENETICS, DEPARTMENT OF MEDICAL SCIENCES AND DEPARTMENT OF MOTHER AND CHILD, UNIVERSITY HOSPITAL S. ANNA FERRARA, FERRARA – MEDICAL GENETICS)
FRANCESCA GUALANDI (UNIT OF MEDICAL GENETICS, DEPARTMENT OF MEDICAL SCIENCES AND DEPARTMENT OF MOTHER AND CHILD, UNIVERSITY HOSPITAL S. ANNA FERRARA, FERRARA – MEDICAL GENETICS)
ALESSANDRA FERLINI (UNIT OF MEDICAL GENETICS, DEPARTMENT OF MEDICAL SCIENCES AND DEPARTMENT OF MOTHER AND CHILD, UNIVERSITY HOSPITAL S. ANNA FERRARA, FERRARA – MEDICAL GENETICS)
RITA SELVATICI (UNIT OF MEDICAL GENETICS, DEPARTMENT OF MEDICAL SCIENCES AND DEPARTMENT OF MOTHER AND CHILD, UNIVERSITY HOSPITAL S. ANNA FERRARA, FERRARA – MEDICAL GENETICS)

Presentatore

RITA SELVATICI (UNIT OF MEDICAL GENETICS, DEPARTMENT OF MEDICAL SCIENCES AND DEPARTMENT OF MOTHER AND CHILD, UNIVERSITY HOSPITAL S. ANNA FERRARA, FERRARA)

Modalità

Oral Communication

Abstract

Background: Dystrophinopathies are a group of X-linked genetic disorders caused by DMD gene mutations. Next-generation sequencing (NGS) has greatly improved our ability to identify rare cases with complex rearrangements. Here we report 3 patients with DMD mutations identified exclusively by NGS.
Methods: The following NGS approaches were used: i) targeted NGS-panel for Patient-1; ii) Whole Exome Sequencing (WES) for Patient-2; iii) Long-Read WGS (LR-WGS) for Patient-3.
Results: Targeted NGS-panel in Patient-1 identified the deletion c.6439-59019_6459del of approximately 59 Kb extending between intron 44 and the first 21 nucleotides of exon 45 which resulted in exon 45 skipping, as highlighted by RNA analysis with FluiDMD-card. WES analysis in Patient-2 identified the total absence of coverage of the entire DMD gene and several contiguous genes. The extensive deletion of about 10Mb in the chrXp21.3p21.1 region was confirmed by array-CGH. LR-WGS performed in Patient-3 identified a large inversion of almost 15Mb involving intron 1 of the NHS gene and intron 44 of the DMD gene, thus justifying the complex phenotype of DMD and cataract. RNA analysis by FluiDMD-card addressed the identification of the breakpoint in the DMD gene.
Conclusion: NGS has revolutionized the field of genetic diagnostics by allowing the simultaneous analysis of multiple genes or even the entire exome or genome. The benefits in DMD diagnosis not only include the identification of common mutations but also complex mutations that are often difficult to detect using traditional methods.
Grants: EU-project Solve-RD GA number: 779257. Several authors are members of ERN-NMD-Project-ID N°870177 and ERN-ITHACA- EU F.P.A. ID:3HP-HPFPA ERN-01-2016/739516.