What is HRD ?

[Iside]

I keep seeing this & do not understand it’s meaning!!! Please enlighten me. Thankyou Iside

[Lyndy]

Homologous recombination deficiency… I know I had to look it up too! It’s to do with the way the body mends double helix breaks in dna… xx

[Iside in reply to Lyndy]

Hi Lyndy,I’m almost glad I didn’t know before, your explanation is as understandable as Double Dutch. However I Thankyou very much for explaining. Cheers Iside

[OvacomeSupport Partner My Ovacome Team]

Hello Iside

You may find these blog posts on our website useful in explaining HRD further:

ovacome.org.uk/Blog/olapari...

ovacome.org.uk/Blog/about-brca

I hope this is helpful. If you have any further questions please do get in touch either through the forum, or call the supportline on 0800 008 7054 or email [e-mail]

Best wishes

Anna

Ovacome Support

[soyoon]

Our DNA forms continuous double strands like a ladder, and it can break one strand upon exposure to things like UV for instance. But, the single strand break still allows DNA stranded structures to remain as long as it is repaired. If both strands are broken, DNA can not be repaired, and cells with the DNA die. So, it is critical to repair single strand breaks before they become double strand breaks. Thinking of DNA as a ladder would make it easier to understand.

Our body has systems in place to repair these single strand breaks through a process called homologous recombination, which are carried out by BRCA and PARP. If you have mutations in BRAC genes or deficiency in homologous recombination (HRD), single strand DNA repair can not occur very well, so your DNA accumulate mutations, e.g., breast and ovarian cancers. If PARP is not working well during DNA repair, the single strand break becomes double strand breaks, then the cells die. That is why PARP inhibitors work well among individuals with BRCA mutations and deficiency in homologous recombination (HRD), because these mutations/deficiencies would generate many single strand breaks without repair. Without these mutations, DNA single strand breaks are efficiently repaired, so PARP inhibitors can not work well.

Hope it helps.

[delia2 in reply to soyoon]

Great explanation!