Meckel syndrome in different populations.

We report on 18 infants from 13 families where the infant was affected with the Meckel syndrome. The parents belong to various national groups--Russians, Byelorussians, Poles, Ukranians, Letts, and Tatars. One child was from an incestuous union (half-sister and half-brother), in 4 families the parents were natives of the same or neighboring villages; other parents apparently were not related. Excluding 3 couples from Central Russia, the Ukraine, and Tatary, the other 10 families were the inhabitants of the Moscow region, Byelorussia, and Latvia. In 3 of these families at least one grandparent was of Tatar descent. At the same time the frequency of Tatars in these regions is less than 1%. Using the Newton binomial distribution it was shown that the hypothesis about equal frequency of the Meckel syndrome gene among Tatars and other national groups under study may be excluded completely, and therefore the alternative hypothesis about an unusually high frequency of this gene among Tatars must be accepted. Such analysis may be useful for comparative evaluation of gene frequencies in populations which cannot be studied directly.