Genetic drift of marker Y chromosome del(Y)(q12) in Khanty from the lower Ob river.

A cytogenetic study of Khanty from the lower Ob river in West Siberia has detected a high frequency of the Y chromosome heterochromatin subtotal deletion--del(Y)(q12). This morphologically identical deletion was found in 32 of 154 males examined (20.8%). The carriers had 10 different surnames. Taking into account the small size, isolation by distance, and historical peculiarities of the surname formation of the population, it has been concluded that the high frequency of the del(Y)(q12) results from the genetic drift of the marker chromosome.