NO, Lupus is not hereditary in the vast majority of cases, although it is partly explained by genetic factors.  The risk of transmitting the disease to your children is therefore very low. Children of a lupus patient have less than a 1% risk of developing the disease because many other factors are at the origin of lupus. The weight of genetic factors is really low as illustrated by the example of identical twins (homozygous) who have the same genetic heritage. In case of lupus in one of the 2 twins, the other twin only has a 30% risk of developing the disease over the course of his/her life. This relatively low risk demonstrates that other determining factors are not genetic.

Two specific situations deserve to be explained:

 Neonatal lupus is a misnamed condition as this disease does not have much in common with systemic lupus. It is a very rare disease that occurs in the newborn. It is directly related to the passage of certain antibodies that the mother produces to the baby through the placenta during pregnancy. These are anti-SSA or anti-SSB antibodies, that can be observed in certain autoimmune diseases including systemic lupus, but also Sjögren syndrome. These antibodies can also be present in the mother without her being sick. This form of lupus can be detected by fetal ultrasound.

It can be characterised by the occurrence of a rash which occurs in the first weeks of the baby's life, and then gradually disappears, when the mother's antibodies disappear from the baby's blood (in the first 6 months of life).

There can be more severe and permanent lesions, which affect the baby's heart, resulting in cardiac electrical conduction abnormalities. These can be detected on fetal ultrasound, by measuring the frequency of the baby's heart rhythm.

This complication is extremely rare and affects less than 1% of children born to mothers with anti-SSA or SSB antibodies. However, it sometimes justifies special treatment at birth.

There are a few families with a significant risk of familial lupus.  This is due to rare genetic factors (such as certain deficits in complement fractions) that can be passed down from generation to generation. It is most often impossible to predict unless this precise genetic factor is known. In practice, these rare exceptions do not justify a family genetic study before having children (unless it is known that other family members have a genetic abnormality predisposing to lupus). This complicated research would not accurately predict the risk. Currently, there is therefore no reason to systematically provide genetic counselling before considering pregnancy with lupus. The only exception would be the knowledge of genetic abnormality in the family of one of the members of the couple.