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DMXX
01-09-2013, 08:08 PM
Distribution of the Lactase Persistence-Associated Variant Alleles -13910(*)T and -13915(*)G among the People of Oman and Yemen.
Al-Abri AR, Al-Rawas O, Al-Yahyaee S, Al-Habori M, Al-Zubairi AS, Bayoumi R. Hum Biol. 2012 Jun;84(3):271-86. doi: 10.3378/027.084.0310.



Abstract The high prevalence of lactase persistence (LP) among the people of Saudi Arabia is associated with the -13915(*)G variant allele upstream of the lactase gene (LCT). We, therefore, examined the frequency of the commonly known LP associated SNPs among randomly collected samples from Omani and Yemeni adult populations and obtained further data on the distribution of the two most common LP-associated variants, -13910(*)T and -13915T(*)G, in the Arabian Peninsula. The DNA fragment containing all the reported LP- associated SNPs was amplified and genotyped. The frequency of the -13915(*)G allele was highest among Dhofari Arabs of southern Oman (0.72) followed by Yemeni Arabs (0.54) and Arabs of northern Oman (0.14). It was not detected in Omanis of Asian origin. The frequency of the -13910(*)T allele was extremely low in Arabs of northern and southern Oman (0.00-0.01) and Yemenis (0.002). However, it had a frequency of 0.160 among Omanis of Asian origin. Results show that the highest frequency of the LCT -13915(*)G variant allele appears to be in the south of the Arabian Peninsula with clinal decrease within the Peninsula and further out in surrounding countries.


Not surprising that 13910T was "extremely low" in frequency.

newtoboard
01-10-2013, 04:45 PM
Distribution of the Lactase Persistence-Associated Variant Alleles -13910(*)T and -13915(*)G among the People of Oman and Yemen.
Al-Abri AR, Al-Rawas O, Al-Yahyaee S, Al-Habori M, Al-Zubairi AS, Bayoumi R. Hum Biol. 2012 Jun;84(3):271-86. doi: 10.3378/027.084.0310.



Not surprising that 13910T was "extremely low" in frequency.

Do you have a link to 13910T's distibution in Asia and the steepe? I remember Jean M saying it achieved its secondary peaks somewhere in South-Central Asia and N. India. I'd like to see its distbution in various Indo-Iranian speaking poulations espcially Osssetians and Southern Indo-Aryan Speakers (Marathi and Konkani).

DMXX
01-10-2013, 06:50 PM
This is what you are referring to.


http://img255.imageshack.us/img255/5096/lactasemutatiion13910t.jpg

One must not become fixated on everything connecting Europe and the Indian Subcontinent.

If there was an absolute correlation between 13910T and Indo-Europeans, you would expect:
- A greater presence in South-Central Asia proper rather than the Indus (notice the Uzbek/Tajik sample node is, as with the Middle-East, <10%)
- A greater presence in East Europe rather than West
- A greater presence in Southeast Europe rather than Africa!

Post-IE migration events not withstanding, such as the Turkish expansion, 13910T at the very best in my opinion represents yet another casual marker that does connect South Asia and Europe in some manner.

I wouldn't consider this anywhere near as informative as actual autosomal DNA component results.