Kim West was separated from her newborn son shortly after birth in the USA, following her teenage pregnancy. Recently, Kim was contacted by her son. They fell in love, took up an intimate relationship and are now planning to have a child together.

What does the Torah say about this scenario?

GSA – genetic sexual attraction – describes feelings of love between closely-related blood relatives.

The Book of Samuel reports a GSA situation, when Amnon, the son of David and royal prince, fell sick with love for his half-sister Tamar.

When jumped by Amnon, Tamar begs her half-brother not to rape her, claiming that their father David might be able to find a dispensation for them to be together legitimately.

This was a one-sided attraction, ending in a crime. But what about consensual feelings? Are they conceivable in the mindset of the Torah?

Maimonides comments that it is not inconceivable that brothers marry their sisters, just as happened in Pharaonic dynasties. However, this is not part of the Divine plan.

Human beings should seek a partner who is different and negotiate a life together.

It is precisely the unknown which is kosher grounds for nurturing a relationship, and not the known.

Psychologists have responded critically to Kim West and her desire to have a child with her son, pointing out that her urge to bond sexually with him is the result of wishing to compensate for feelings of guilt, having abandoned him years earlier.

However, masking guilt, anger and the need for reconciliation in the context of therapy with a sexual manifestation of love, will only serve to sow destructive seeds later.

Critics may respond by saying that this is merely a new frontier in lesbian, gay, bisexual, trans and queer, which needs to be accepted.

However, there is clearly a frontier here, which both Torah and secular science agree is harmful to cross.

Aside from the legal issue, which is clearly forbidden according to Torah, the curse imposed by Torah on first-degree liaisons is perfectly understandable as self-fulfilling. Genetic aberrations and infertility threaten offspring of such unions.

In Judaism, the product of such a liaison is a mamzer, a child who, through no fault of their own, is considered a bastard and thereafter is unable to marry into the community.

We were created to unite differences, even if it means taking a chance and marrying across divides in the human race – facing the natural challenges set for us by the Almighty.

• Ariel Abel is rabbi at Liverpool’s Princes Road synagogue