Frequencies of bb, Bb and BB genotype were 70. 4% , 27. 2% and 2.5% respectively in the 81 Hui ethnic children and they were 91.1% , 7.1% and 1.8% respectively in the 169 Han ethnic children.

• 发现在回族81例中；bb型57例(70.；4%25)；Bb型22例(27