Frequently asked questions

Results from DDD

Q. When will we hear back about results?
A. We aim to feedback relevant research findings to clinical teams as fast as possible, but it may take several years to find a diagnosis. Your geneticist or research nurse/ genetic counsellor will contact you if there are any results, as these will usually need to be validated within the NHS (which may involve providing another sample). We intend to re-analyse all the DNA from the children in DDD at the end of the study (October 2016) so may report results any time until then. Your genetics department will also know at this time if we haven’t been able to find a diagnosis. However, the DDD team is also committed to securing additional funding to continue to analyse the data from consented families for at least the next 5 years. This includes pursuing whole genome sequencing for those patients who remain undiagnosed after exome sequencing. Therefore, it is possible you may receive a diagnosis from DDD beyond October 2016.
Q. What information will you feedback?
A. We aim to feedback only findings that are relevant to your child’s developmental disorder. We will not feedback other findings (such as non-paternity, or susceptibility to other diseases) even if they are clinically actionable.
Q. Will you tell us if you find something important in any of our family’s genomes which doesn’t relate to our child’s developmental disorder?
A. Currently no. We analyse the data specifically only looking for genetic changes that are likely to explain your child’s developmental disorder. We filter the data extensively to remove as many other changes as possible, and we won’t be searching for alterations associated with any other conditions (which are often termed ‘incidental findings’).

Providing your samples

Q. How quickly do we need to return our samples?
A. Please try to return your samples in the FREEPOST padded envelopes provided within 2 weeks of receiving them. This ensures that there won’t be any delay processing your samples.
Q. What child samples do you need?
A. Ideally we would like a saliva sample from the child (and both parents) as well as a DNA sample previously extracted from blood at your regional genetic service if it already exists. However, we will accept children with just one of these samples – either just saliva or just a DNA sample extracted from blood. We will provide you with special tubes for collecting the saliva, with sponges to help with collection.
Q. What happens if I spill a sample, spit in the wrong tube or break a tube?
A. Please try not to spill the liquid in the lid of the tube, or break a tube. Although we can provide replacement kits – just get back in touch with your NHS genetics service and tell them what happened – the kits are quite expensive, and any budget spent on replacement kits means that fewer people will be able to take part in the study. Once the samples reach the Sanger Institute, the lab can work out if any of the family have accidentally spat in the wrong tube, so please don’t worry about correcting this.
Q. How will you know which sample belongs to whom?
A. All the sample tubes are labeled with a unique barcode, which was linked to your family at your NHS genetics clinic prior to sending the kits. This is all the information we need to link the data back to you. Please don’t send any further identifying information with your samples – we are trying hard to respect and protect your confidentiality, so all the samples are anonymous to the scientists at the Sanger Institute.
Q. What happens if a sample fails?
A. A sample may fail for a variety of reasons, including insufficient DNA (which varies between people), poor DNA quality, laboratory issues with processing the sample, or inconsistencies in the analysis. We will report back to the regional clinical genetics service simply that the sample has failed, but will not give the reason. If either or both parent samples fail, we will continue to process the sample from the child and remaining parent. At this time, we are unable to offer participants multiple attempts at providing a sample, due to budget constraints.
Q. Will I have to give another sample in future?
A. Maybe. Because of the stringent quality control processes we use, some of the samples provided may not be appropriate for all our tests. If this is the case, we will let your clinical team know that we need another sample from your child. Also, because the tests are being done at a research institute, all the results will have to be checked in an NHS lab and you may need to give another sample for these validation tests.

Eligibility for DDD

Q. Who is eligible for DDD?
A. DDD is focusing on any children with undiagnosed developmental disorders. Your geneticist must decide whether your child meets the more detailed criteria for entry into the study.
Q. Is DDD just for families within the UK?
A. Yes; we will only recruit through UK NHS clinical genetics services and cannot accept samples from outside of the UK.
Q. Will DDD accept families who have already had other genetic tests?
A. Yes, so long as a diagnosis for the developmental disorder has not been found.
Q. Will DDD accept children with only one parental sample?
A. Yes, although we prefer to have samples from both biological parents if possible. Parental samples are important for sifting and interpreting the huge amount of genetic data generated by the study to try to find the variant(s) causing the child’s developmental problems. We are able to accept children into the study where samples from only one parent are available, but the chances of finding a diagnosis will be reduced. We cannot accept children into the study if there are no parental samples.
Q. Are you only accepting children who are still alive?
A. We can accept DNA samples (from blood) from deceased children into DDD, but a child must have been liveborn to be eligible for the study.

Information about DDD and Other Studies

Q. How do I find out more about DDD?
Please read everything on for information about the study, and speak to your geneticist or genetic counsellor if you have any questions. You can also contact SWAN UK (Syndromes Without A Name; or Unique (Rare Chromosomal Disorder Group; with
any questions.
Q. Can I participate in the DDD study?
A. Only if you have already signed a DDD consent form. Unfortunately we are no longer recruiting new patients to DDD. If your child has an undiagnosed developmental disorder please speak with your paediatrician or GP about the most appropriate tests or referral into other studies. When trying to decide which study is most appropriate, read study websites and ask your genetics department for advice. We suggest that you support studies where the data will be openly accessible for future research, as this maximizes the benefits for everyone, but cannot advise further. Ultimately, it is your choice as to which research project you prefer.