Jnetics in Schools

Jnetics in Schools is a carrier testing programme for sixth-form students, primarily in all eight mainstream Jewish secondary schools in the UK.

What are Jewish genetic disorders (JGDs)?

These are genetic disorders which are more common in people who have Jewish ancestry than those in the general population.

This does not mean that only Jewish people are affected, but it does mean that Jewish people, or those of Jewish descent, have an increased risk of having one of these conditions.

Tay-Sachs disease is the best-known example of a JGD, but research has identified a number of other serious disorders that can potentially be prevented through carrier screening.

What is carrier screening?

Carrier screening gives people the opportunity to find out if they are a ‘carrier’ of a genetic condition. Carriers of recessive disorders are typically not affected themselves but are at increased risk of passing on a genetic condition if their partner is also a carrier of the same disorder. Screening involves taking a cheek swab and testing it to see if there is a ‘mutation’ (a genetic fault or alteration) for a particular genetic disorder.

Which Jewish genetic disorders are covered in Jnetics’ carrier screening?

The Jnetics screening covers 47 of the most severe recessive genetic disorders that are relatively more common in either Ashkenazi or Sephardi/Mizrahi Jews.

A full list of the disorders covered by Jnetics screening can be found here.

Why have carrier screening?

While Jewish genetic disorders vary in severity, those covered by Jnetics can all be severely debilitating and most cause shortened lifespan. At this time most lack any effective treatment but can be prevented through effective carrier screening. Though rare, these conditions are devastating and can typically occur even when there is no known family history.

Anybody of Jewish ancestry has a 1 in 3 chance of carrying one or more of the severe recessive Jewish genetic disorders that we test for.

Unless screened, carriers often go undetected until it is too late. The best time to screen for these conditions is before starting (or growing) a family as it gives people the greatest number of reproductive options available should they be at risk of having an affected child.

How are genetic disorders passed on?

The disorders covered in this screening programme follow an autosomal recessive inheritance pattern, shown in the diagram. This means that two copies of an altered gene must be present for the disorder to develop. The diagram demonstrates that if both parents are carriers of the same disorder (they each carry a single altered gene), then each child will have a 25% chance of inheriting two copies of the altered gene and being affected by the disorder. For every pregnancy, there is also a 50% chance that the child will be a carrier but not develop the genetic condition themselves.

Who is eligible for Jnetics in Schools carrier screening?

Testing is available for anyone aged 16 or over, in sixth-form, who has at least one blood Jewish grandparent.


  • YES. Over 95% of the couples with children affected by a disorder have no family history of the condition because the gene is silently passed on through generations by healthy carriers.
  • YES. Carrier status for one disorder has no impact on their carrier status for the other disorders.
  • NO. Carriers of these recessive disorders DO NOT develop the condition/s themselves BUT if you and (future) partner are BOTH carriers of the SAME condition then you are AT RISK of passing on the condition to your children.
  • With recessive disorders, BOTH partners in a couple need to be carriers of the SAME condition for there to be a risk of having affected children. Where this is the case, with each pregnancy, there is a 25% chance that the child will be affected (develop the condition).
  • It is extremely advisable for individuals who are identified as carriers to ensure that the partner is also screened before planning a family.
  • If you find out that you are a carrier, it is also suitable to inform their siblings of this. There is a 50% chance that your sibling will also be a carrier of the same recessive disorder themselves.
  • YES. Jnetics’ screening is now relevant to anyone with Jewish ancestry – whether that is Ashkenazi, Sephardi or Mizrahi (this was not the case prior the September 2021)
  • On-line registration – to book a time slot and complete a short background information form.
  • Screening – registered students arrive at their pre-booked time slot and are directed to a trained screening advisor who will review key information with you, answer any questions then provide an explanation and kit for you to give a small saliva sample.
  • Analysis – saliva samples are sent to an accredited lab for analysis.
  • Results – results are processed by a dedicated NHS Genetic Counsellor, who sends your results report to you (and a copy to your GP) by email up to 20 weeks after the screening event. The genetic counsellor’s phone number is included for you to be in contact if you have any questions.
  • Jnetics has a clinic in partnership with the NHS that covers the same severe recessive JGDs. Though part subsidised, participants at the clinic pay the lab processing cost of £250 per individual.
  • Dor Yeshorim screening is appropriate for someone who plans on finding a partner via the ‘shidduch system’. PLEASE NOTE: Dor Yeshorim will not screen someone who they know has been informed of their results from a different screening programme, such as Jnetics screening.
  • All eligible students can have Jnetics screening, however, if you know that you want to be part of the ‘shidduch system’, then Dor Yeshorim may be a more appropriate screening option for you.
Further FAQs

More information can be found on other pages of our website, alternatively please contact us at students@jnetics.org or call 020 8158 5123.

Dominant inheritance

Autosomal dominant inheritance occurs when an alteration in just one copy of an inherited gene pair causes a genetic disorder.

Read more →

Recessive inheritance

Autosomal recessive inheritance occurs when alterations in both copies of an inherited gene pair are required to cause a genetic disorder.

Read more →