Yes, but you should do it in an age-appropriate manner and in a language that the child can understand. Children need to hear about HD from their parents and not from someone else. Otherwise they might think that the affected parent's behaviour is due to alcoholism or drug use, or that the parent does not love them.

As a rule, it is important to tell children about HD if a person in the family is showing symptoms. This prevents the children from drawing wrong conclusions about the person's behaviour.

In general, a minimum age of 18 is recommended, as it is hoped that at this age a person has the maturity needed to deal with the awareness of carrying the HD gene. However, in exceptional cases, it may be reasonable to perform the genetic test in children, for example if they show signs of juvenile HD or in pregnant women under the age of 18.

In this case, you should consider genetic counselling before starting a family. Your husband may undergo genetic testing to see if he carries the HD gene. If he does not carry the mutant gene, your children will not inherit the disease. If he does carry the HD gene, then each of your children will have a 50% risk of inheriting the HD gene.

Deciding whether to have children or not despite the risk of HD is a personal decision which only you and your spouse can make. We recommend that you do it with the guidance of a genetic counsellor. There are currently special genetic procedures available in some countries to minimise the risk. You should also consider that by the time your children grow up there might be a cure for HD.

The genetic techniques currently available enable testing of unborn children, known as prenatal (before birth) diagnosis. However, testing of unborn children needs to fulfil certain medical and legal criteria, which may be country specific.

There are two classical procedures of prenatal diagnosis: Amniocentesis (also called amniotic fluid test) is a procedure in which amniotic fluid containing cells of the unborn child is collected with a needle, usually after the 14th week of pregnancy. Collection of sample from the chorionic villi (tissue of the placenta) can be done earlier (between 9 and 12 weeks of pregnancy), but is more risky to the unborn child.

Yes. The “exclusion test” compares the genetic pattern of the unborn child with the genetic pattern of the grandparents.

Yes, the preimplantation genetic diagnosis (PGD), also known as embryo screening, is a modern diagnostic procedure combined with in vitro fertilisation (IVF). The embryos are screened prior to implantation. Using this technique, only embryos inheriting normal copies of the gene are implanted into the womb. Hence, PGD gives a couple the chance of conceiving a child that is unaffected by HD, regardless whether the man or the woman carries the HD gene. However, PGD is forbidden in some countries by laws aimed at embryo protection.