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Optimized testing strategy for the diagnosis of GAA-FGF14 ataxia/spinocerebellar ataxia 27B.

Authors :
Bonnet C
Pellerin D
Roth V
Clément G
Wandzel M
Lambert L
Frismand S
Douarinou M
Grosset A
Bekkour I
Weber F
Girardier F
Robin C
Cacciatore S
Bronner M
Pourié C
Dreumont N
Puisieux S
Iruzubieta P
Dicaire MJ
Evoy F
Rioux MF
Hocquel A
La Piana R
Synofzik M
Houlden H
Danzi MC
Zuchner S
Brais B
Renaud M
Source :
Scientific reports [Sci Rep] 2023 Jun 15; Vol. 13 (1), pp. 9737. Date of Electronic Publication: 2023 Jun 15.
Publication Year :
2023

Abstract

Dominantly inherited GAA repeat expansions in FGF14 are a common cause of spinocerebellar ataxia (GAA-FGF14 ataxia; spinocerebellar ataxia 27B). Molecular confirmation of FGF14 GAA repeat expansions has thus far mostly relied on long-read sequencing, a technology that is not yet widely available in clinical laboratories. We developed and validated a strategy to detect FGF14 GAA repeat expansions using long-range PCR, bidirectional repeat-primed PCRs, and Sanger sequencing. We compared this strategy to targeted nanopore sequencing in a cohort of 22 French Canadian patients and next validated it in a cohort of 53 French index patients with unsolved ataxia. Method comparison showed that capillary electrophoresis of long-range PCR amplification products significantly underestimated expansion sizes compared to nanopore sequencing (slope, 0.87 [95% CI, 0.81 to 0.93]; intercept, 14.58 [95% CI, - 2.48 to 31.12]) and gel electrophoresis (slope, 0.84 [95% CI, 0.78 to 0.97]; intercept, 21.34 [95% CI, - 27.66 to 40.22]). The latter techniques yielded similar size estimates. Following calibration with internal controls, expansion size estimates were similar between capillary electrophoresis and nanopore sequencing (slope: 0.98 [95% CI, 0.92 to 1.04]; intercept: 10.62 [95% CI, - 7.49 to 27.71]), and gel electrophoresis (slope: 0.94 [95% CI, 0.88 to 1.09]; intercept: 18.81 [95% CI, - 41.93 to 39.15]). Diagnosis was accurately confirmed for all 22 French Canadian patients using this strategy. We also identified 9 French patients (9/53; 17%) and 2 of their relatives who carried an FGF14 (GAA) <subscript>≥250</subscript> expansion. This novel strategy reliably detected and sized FGF14 GAA expansions, and compared favorably to long-read sequencing.<br /> (© 2023. The Author(s).)

Details

Language :
English
ISSN :
2045-2322
Volume :
13
Issue :
1
Database :
MEDLINE
Journal :
Scientific reports
Publication Type :
Academic Journal
Accession number :
37322040
Full Text :
https://doi.org/10.1038/s41598-023-36654-8