Leah Marks

Leah  Marks

My PhD was in Developmental Medicine and I am currently a Senior Lecturer in Medical Genetics at the University of Glasgow. I have also been a Senior Fellow of the HEA since 2016.

Location Glasgow University


  • Hi Ken, interesting point - there are continually 'mistakes' being made during the copying of our DNA when our cells divide. These do get repaired very readily by DNA repair mechanisms, which is just as well, otherwise cancers would be much more common. Some people do have these repair systems impaired which can predispose them to cancers.
    However there are...

  • Very good question Joshua! In short it is publically available information. I quote from this website <https://www.genome.gov/human-genome-project/Completion-FAQ>

    "Every part of the genome sequenced by the Human Genome Project was made public immediately, and new information about the genome is posted almost every day in freely accessible databases or...

  • Should be there now (and subtitles)

  • Hi Angharad, let me check up on that - there should be a transcript for it...

  • Hi there, there's a good image of the different groups on this webpage - along with more information on their characteristics


  • Hi Juha,
    If you're interested in this topic (and why in actual fact there is a special form of DNA which is left handed - called Z-DNA) here is a link you might find interesting


  • Sometimes drawing a family tree can be really difficult - and that reflects what can happen in the clinic. Not all patients will know all of their family history, and the clinician will just have to work with what is known.

  • Leah Marks made a comment

    Good to see you've been thinking about the question posed at the end of the video. Your answers are correct - chromsome, being much bigger than 1, has too many genes on it to be survivable with an extra copy.

  • We'll learn a bit more about both in the coming steps - both can be very detrimental to the cell/organism.

  • Yes that's always wise to be careful and respect others right to privacy.

  • Thanks Victoria - that's a useful suggestion and one which we'll hopefully be able to look into for the next run of the course.

  • Nice to see people still joining - we hope you find it useful! If you've got questions it's best to ask them in the current week as that's the one we'll pay most attention to. But feel free to work through the other weeks at your own pace.

  • No I've not heard of that - although I always think that a bit of knowledge of where we have come from in medicine can help inform current thinking and understanding!

  • Leah Marks replied to [Learner left FutureLearn]

    Yes - you're right - very well spotted :-) Have fixed that now! Thank you!

  • Leah Marks made a comment

    Nice to meet you all too - we'll try and answer as many questions as we can but it would be great if you can help each other out too!

  • Great to hear from you - keep the introductions coming! I'm glad that we've got people from such a range of backgrounds, hopefully there will be something for everyone here!

  • Sorry that you did't enjoy the videos - we purposely chose not to deliver them in lecture format as lectures been shown not to be the most effective way of presenting information. Short videos tend to work better in terms of engaging an audience. I've been reviewing the questions weekly (for the current week as mentioned in week 1) and answering them when...

  • Yes I would agree with your comments!

  • Hi Shabtai, I think the best way of explaining it is that the modifications that are made to the DNA (but which aren't base changes) can be passed down the generations from cell to cell. Does that make sense?

  • Some interesting information on this aspect (from a a patient's perspective) here:

  • Interesting point. In trials we are using drugs that we genuinely don't know have an advantage. Sometimes, if a drug is shown to have a marked advantage the trial will be stopped early to prevent disadvantage to those on the placebo.

  • @ReubenSoi It's very uncommon to have a predisposition to leukemia but there do seem to be some rare variants implicated in this - see this article

  • HI there,

    The mechanisms of resistance mechanisms are varied but can, for example, be because of BCR-ABL gene amplification or, more commonly because of mutations within the BCR-ABL kinase domain where the drug binds. More on this in the next step....


  • Good question - more on this in week 6!

  • Hi Sandra, Yes the videos were made several years ago - the course first ran in 2014. However we have updated various aspects of it since then e.g. by adding in immunotherapy. But in such a quickly moving field there will always be more up to date information and I would love to do another update this year.

  • Yes - the ability to target the radiotherapy more specifically certainly leads to less systemic effects.

  • It's certainly difficult to be sure are no rogue cells which have escaped - sometimes chemotherapy is offered just to mop up as many of these as possible.

  • Very good questions - we look at health economics a bit more in week 6!

  • If you click on the padlet link https://genome.cshlp.org/content/early/2017/05/16/gr.219915.116.full.pdf

    and then click the + sign in the bottom right hand corner I think that should work!

  • Yes you're right Rachael - if a condition is dominant both parents would only need one copy of the variant to be affected - and their child might inherit both unaffected copies.

  • I guess the key thing is that all genetic counselling is 'non directive' i.e. people are given the information to allow them to make informed choices - even if those choices might not reflect the decision the counsellor would have made for themselves.

  • These are all really interesting issues that you have raised - with some good points made!

  • Hmmm yes unfortunately it seems to be offline at the moment....

  • Have a look at this article which deals with that subject!


  • Welcome to everyone - whatever your motivation for doing this course is. We really hope you will find it informative and enlightening. If you have questions then try to post them in the current week as that's where we will be focusing on in terms of moderating the comments threads and discussions. But please do introduce yourself on here even if you are...

  • @ReubenSoi Pain in cancer can certainly be caused by the tumour pressing on nerves (or other body structures such as organs). Cancer Research has an informative section on this

  • We'll take a look in week 3 at how exposure to certain environmental factors (of which asbestos is one) can make people more likely to develop cancer - hopefully that will help explain it a bit.

  • Yes - if you think of the fact that in our bodies, errors in DNA copying are happening all the time. Most of these will be picked up and corrected, or will not matter but sometimes these changes escape the detection systems (particularly in cells with mutations in the detection systems themselves). Some mutations give cells a survival advantage by allowing...

  • Good question - that's something you'll hopefully learn more about as we go through the course. Week 4 has a couple of videos from a pathologist - one of the people who would be involved in 'staging' the cancer and in we'll talk more about resistance to therapies in week 5 and 6.

  • Hi Reuben, in NF1 you can get tumours developing in a number of different locations - see here for more information https://www.nhs.uk/conditions/neurofibromatosis-type-1/symptoms/

  • Yes there'll be plenty on this in the coming weeks- and more resources in a subsequent step this week if you are interested.

  • Since the vaccine doesn't protect against all forms of HPV screening is still recommended. When and how often has been debated - can anyone find any useful resources on this?

  • Good question - what do other people think? Is it that early detection rates have improved compared to previous decades, or are there environmental influences that could be causing an increase? Or other factors?