TY - JOUR
T1 - Molecular Diagnosis of Usher Syndrome
T2 - Application of Two Different Next Generation Sequencing-Based Procedures
AU - Licastro, Danilo
AU - Mutarelli, Margherita
AU - Peluso, Ivana
AU - Neveling, Kornelia
AU - Wieskamp, Nienke
AU - Rispoli, Rossella
AU - Vozzi, Diego
AU - Athanasakis, Emmanouil
AU - D'Eustacchio, Angela
AU - Pizzo, Mariateresa
AU - D'Amico, Francesca
AU - Ziviello, Carmela
AU - Simonelli, Francesca
AU - Fabretto, Antonella
AU - Scheffer, Hans
AU - Gasparini, Paolo
AU - Banfi, Sandro
AU - Nigro, Vincenzo
PY - 2012/8/29
Y1 - 2012/8/29
N2 - Usher syndrome (USH) is a clinically and genetically heterogeneous disorder characterized by visual and hearing impairments. Clinically, it is subdivided into three subclasses with nine genes identified so far. In the present study, we investigated whether the currently available Next Generation Sequencing (NGS) technologies are already suitable for molecular diagnostics of USH. We analyzed a total of 12 patients, most of which were negative for previously described mutations in known USH genes upon primer extension-based microarray genotyping. We enriched the NGS template either by whole exome capture or by Long-PCR of the known USH genes. The main NGS sequencing platforms were used: SOLiD for whole exome sequencing, Illumina (Genome Analyzer II) and Roche 454 (GS FLX) for the Long-PCR sequencing. Long-PCR targeting was more efficient with up to 94% of USH gene regions displaying an overall coverage higher than 25×, whereas whole exome sequencing yielded a similar coverage for only 50% of those regions. Overall this integrated analysis led to the identification of 11 novel sequence variations in USH genes (2 homozygous and 9 heterozygous) out of 18 detected. However, at least two cases were not genetically solved. Our result highlights the current limitations in the diagnostic use of NGS for USH patients. The limit for whole exome sequencing is linked to the need of a strong coverage and to the correct interpretation of sequence variations with a non obvious, pathogenic role, whereas the targeted approach suffers from the high genetic heterogeneity of USH that may be also caused by the presence of additional causative genes yet to be identified.
AB - Usher syndrome (USH) is a clinically and genetically heterogeneous disorder characterized by visual and hearing impairments. Clinically, it is subdivided into three subclasses with nine genes identified so far. In the present study, we investigated whether the currently available Next Generation Sequencing (NGS) technologies are already suitable for molecular diagnostics of USH. We analyzed a total of 12 patients, most of which were negative for previously described mutations in known USH genes upon primer extension-based microarray genotyping. We enriched the NGS template either by whole exome capture or by Long-PCR of the known USH genes. The main NGS sequencing platforms were used: SOLiD for whole exome sequencing, Illumina (Genome Analyzer II) and Roche 454 (GS FLX) for the Long-PCR sequencing. Long-PCR targeting was more efficient with up to 94% of USH gene regions displaying an overall coverage higher than 25×, whereas whole exome sequencing yielded a similar coverage for only 50% of those regions. Overall this integrated analysis led to the identification of 11 novel sequence variations in USH genes (2 homozygous and 9 heterozygous) out of 18 detected. However, at least two cases were not genetically solved. Our result highlights the current limitations in the diagnostic use of NGS for USH patients. The limit for whole exome sequencing is linked to the need of a strong coverage and to the correct interpretation of sequence variations with a non obvious, pathogenic role, whereas the targeted approach suffers from the high genetic heterogeneity of USH that may be also caused by the presence of additional causative genes yet to be identified.
UR - http://www.scopus.com/inward/record.url?scp=84865585969&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=84865585969&partnerID=8YFLogxK
U2 - 10.1371/journal.pone.0043799
DO - 10.1371/journal.pone.0043799
M3 - Article
C2 - 22952768
AN - SCOPUS:84865585969
VL - 7
JO - PLoS One
JF - PLoS One
SN - 1932-6203
IS - 8
M1 - e43799
ER -