Rs28940871

This position appears to have been flipped between b36 and b37. Extra scrutiny is warranted.

rs28940871, also known as Leu451Val, L451V, or C1351G, is a mutation in the HEXA gene. Some variations of this gene are associated with Tay-Sachs disease.

In a population of Iraqi Jews, this SNP was found in 21 of 62 Tay-Sachs disease carriers (33.9%) and in 0 of 100 noncarriers. The authors estimated that this SNP originated sometime between 1519 BC and 635 AD, with 442 BC as the best estimate (+/- 1,000 years). The Iraqi Jewish community started around 586 BC when the Babylonian king Nebuchadnezzar deported 10,000 to 40,000 of the Jews from the kingdom of Judea to Babylon. This was probably the time of separation of the Iraqi Jews from the rest of the Jewish people. OMIM

23andMe reports the risk allele as C, because it is on the minus strand.