Footnotes

• Twitter @SGorokhova

• Contributors MC, MB and MK designed the gene panel and performed the molecular diagnosis by analysing the sequencing data. ES-C, AS and SA performed the clinical diagnosis of the patients. MC wrote the manuscript in consultation with MK, SG, NL, NB-P and ES-C.

• Funding The authors have not declared a specific grant for this research from any funding agency in the public, commercial or not-for-profit sectors.

• Competing interests None declared.

• Patient consent for publication Not required.

• Provenance and peer review Not commissioned; externally peer reviewed.