You can find useful guidelines at the following link. In the deletion section there are also specific examples for multi-exon deletions.

http://www.hgvs.org/mutnomen/examplesDNA.html

If the breakpoints are not determined, I think you could merge the deletion of the two contiguous exons in one single indication reporting the start position of the first exon and the end position of the second one, as reported in the above webpage:

deletion of exons 2 to 4 (e.g. detected on Southern blot, see Discussion)

coding DNA Reference Sequence

c.13-?_300+?del

Hope this can help!

Thank you for the answer, but I am aware of HGVS website and their guideline. The formula above:

SMN1:c.[(834+1_835-1)_(*577+1_*578-1)del];[(834+1_835-1)_(*577+1_*578-1)del]

was written according to the information found there and on their facebook page:

https://www.facebook.com/HGVSmutnomen

-  "name of the gene":c.[("last positive nucleotide"_"first negative nucleotide")_("last negative nucleotide"_"first positive nucleotide")del].....

- small brackets "()" were used because the deletion was detected by MLPA without sequencing

- "834+1" means that deletion starts somewhere in the intron 6 (official nomenclature: intron 7).

I just want to know how much people (who are in diagnostics, especially using MLPA kits) are using this nomenclature for large deletions/duplication.

Is there anybody who has been involved recently in EMNQ schemes and what were their recommendations?

Thanks in advance.

Dear Sanja Cirkovic,

You can use HGVS nomenclature for LGR. I detected by MLPA the deletion of exon 2 and exon 8 in BRCA1 gene in two Algerian breast cancer patients, respectively. Without determining the genomic breakpoints, according to HGVS nomenclature criteria, the deletions were designated as following

BRCA1 del exon 2  (c.-19-? 80+?del/p.?)

BRCA1 del exon 8  (c.442-? 547+?del/p.?)

In addition, I advise you for the confirmation/validation of the designation of any type of mutation, you have to use the golden software Alamut (if your lab got a license of this wonderful software).

Best regards

Dr Farid Cherbal

Dear dr Cherbal,

Thank you for answering, it is very helpful. So, you are using traditional nomenclature and newly (HGVS) proposed in brackets, am I right?

In the meantime I have contacted people from the https://mutalyzer.nl/ site, and they have confirmed that (A+1_B-1)_(C+1_D-1) designation for exon del/dup is still a proposal, not recommendation of HGVS.

We don't have Alamut software and I'm asking you if it is necessary for us to have it,. because we don't perform sequencing yet.

Best regards,

Sanja

Dear Sanya Cirkovic,

Ya, you got it right. Just to be in line, all papers published on LGR in BRCA genes followed the new HGVS nomenclature.

I do think   Alamut software is an essential/ main/golden bioinformatics tool when we  perform genetic testing and genetics diagnosis.

Best regards

Dr Farid Cherbal