What happens if people need to confirm ancestry with DNA tests in order to… get married? That procedure is used by the Chief Rabbinate and the Rabbinical Courts to check for Jewish ancestry. Although the number of reported cases – 20 – is not high, it poses as a dangerous precedent.

Israel requires Jewish status to register a marriage. It must be proven with documentation and DNA tests are sometimes used as a part of it. In own words of the Chief Rabbi:

In such an instance, the Rabbinical Court is likely, only to help the applicant, to offer to him to do a DNA test to back his claims

David Lau [source]

A story of Oleg Sidorov [more] shows that the procedure is overused for checking the ancestry reaching to even few past generations:

The rabbis suspected that my grandmother had been adopted. (…) They strongly suggested that my grandmother undergo a DNA test to prove her connection to my great-grandmother’s blood relatives. (…) Following the rabbi’s suggestion wasn’t an option. Sidorov’s great-grandmother, who died 16 years ago, was the only one of her siblings to survive the Holocaust. (…) The rabbinate has since placed Sidorov on a list of people who are not permitted to marry under the auspices of the rabbinate, which has sole authority over marriage in Israel. There is no civil marriage. He and his wife were married in a Jewish ceremony in Israel, but the marriage is not recognized by the rabbinate.

Article of Michele Chabin [source]

Particular stories [example] precise the form of the procedure, which appears to rely only on mitochondrial DNA. mtDNA is substantially small part (1%) of the human genome, which resides in bacteria-like organelles inherited from mother (paternal mitochondria generally do not survive fertilization). Apart from controversy of defining people as “not sufficiently pure genetically”, there is a scientific problem with this method – we know cases, where closely related individuals had different mtDNA [example], and only further investigation of the rest of the genome can reveal accurate ancestry.

The story mirrors worldwide trends. In the last decade, DNA tests went from association with a word “forensics” to catching up hearts and minds with “ancestry”. The largest companies in genomic industry are making staggering profits from ancestry tests, and use that revenue for marketing campaigns fueling even more recognition of DNA ancestry tests. This definitely can influence even country-wide procedures, as seen in the described story.