Pitfalls in genetic testing: the story of missed SCN1A mutations

2016-07

Djémié, Tania

Weckhuysen, Sarah

von Spiczak, Sarah

Carvill, Gemma L

Jaehn, Johanna

Anttonen, Anna-Kaisa

Brilstra, Eva

Caglayan, Hande S

de Kovel, Carolien G

Depienne, Christel

Gaily, Eija

Gennaro, Elena

Giraldez, Beatriz G

Gormley, Padhraig

Guerrero-López, Rosa

Guerrini, Renzo

Hämäläinen, Eija

Hartmann, Corinna

Hernandez-Hernandez, Laura

Hjalgrim, Helle

Koeleman, Bobby PC

Leguern, Eric

Lehesjoki, Anna-Elina

Lemke, Johannes

Leu, Costin

Marini, Carla

McMahon, Jacinta M

Mei, Davide

Møller, Rikke S

Muhle, Hiltrud

Myers, Candace T

Nava, Caroline

Serratosa, Jose M

Sisodiya, Sanjay M

Stephani, Ulrich

Striano, Pasquale

van Kempen, Marjan JA

Verbeek, Nienke E

Usluer, Sunay

Zara, Federico

Palotie, Aarno

Mefford, Heather C

Scheffer, Ingrid E

De Jonghe, Peter

Helbig, Ingo

Suls, Arvid

EuroEPINOMICS‐RES Dravet working group

Dravet syndrome

Sanger sequencing

Epilepsy

Genetic screening

Next‐generation sequencing

Journal Article

10.1002/mgg3.217

BACKGROUND: Sanger sequencing, still the standard technique for genetic testing in most diagnostic laboratories and until recently widely used in research, is gradually being complemented by next-generation sequencing (NGS). No single mutation detection technique is however perfect in identifying all mutations. Therefore, we wondered to what extent inconsistencies between Sanger sequencing and NGS affect the molecular diagnosis of patients. Since mutations in SCN1A, the major gene implicated in epilepsy, are found in the majority of Dravet syndrome (DS) patients, we focused on missed SCN1A mutations. METHODS: We sent out a survey to 16 genetic centers performing SCN1A testing. RESULTS: We collected data on 28 mutations initially missed using Sanger sequencing. All patients were falsely reported as SCN1A mutation-negative, both due to technical limitations and human errors. CONCLUSION: We illustrate the pitfalls of Sanger sequencing and most importantly provide evidence that SCN1A mutations are an even more frequent cause of DS than already anticipated.

link

Molecular Genetics & Genomic Medicine 2016; 14(4):457-464

Molecular Genetics & Genomic Medicine