Method for constructing risk model for screening fetal 18 trisomy syndrome by replacing alpha fetoprotein with alpha fetoprotein heteroplasmon L2 and L3

Abstract

The invention discloses a method for constructing a risk model for screening fetal 18 trisomy syndrome by replacing alpha fetoprotein with alpha fetoprotein heteroplasmon L2 and L3. The method comprises the following steps: (1) dividing pregnant women into a case group and a control group according to the existence of 18 trisomy syndrome, wherein pregnant women who are diagnosed as 18 trisomy fetus through amniotic fluid chromosome karyotype analysis are taken into the case group, and randomly selected pregnant women whose fetus develops normally at the same time are taken into the control group; (2) detecting the concentrations of AFP-L2 and AFP-L3 in serum and the free beta-HCG level of two groups of pregnant women, and comparing the median multiple MoM distribution conditions; and (3) during detection, detecting the concentrations of AFP-L2 and AFP-L3 in serum and the level of free beta-HCG of the pregnant women, and when the MOM value of the serum of a to-be-detected pregnant womanis combined with AUC predicted by prenatal age modeling to exceed a set threshold value, judging that the to-be-detected pregnant woman has 18 trisomy syndromes. The method has the beneficial effectsthat AFP-L2 and AFP-L3 replacing AFP to screen 18 trisomes have high sensitivity and specificity, and compared with AFP only, the two markers indeed improve the screening efficiency and reduce the false positive rate.

Description

technical field [0001] The invention relates to the field of medical detection, and mainly relates to a method for constructing a risk model for screening fetal trisomy 18 by substituting alpha-fetoprotein heterogeneity L2 and L3 for alpha-fetoprotein. Background technique [0002] Trisomy 18, also known as Edwards syndrome (Edwards syndrome, ES), is an autosomal trisomy syndrome, and its incidence rate is second only to trisomy 21 or Down's syndrome (Down's syndrome, DS). Its prevalence in live births ranges from 1 / 6 000 to 1 / 8 000, and trisomy 18 often precedes spontaneous abortion. In recent years, with the development of prenatal diagnosis technology, most fetuses with trisomy 18 have been eliminated naturally or artificially terminated, so the incidence of trisomy 18 fetuses is higher than its prevalence in live births, about 1 / 2 500-1 / 2 600 [1] . Most children with trisomy 18 die within 1 year of life, and only 5% to 10% of children survive beyond that age [2] . ...

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Problems solved by technology

AFP-L3 has been reported to be superior to AFP in screening for trisomy 21 [9-12] , but there is no report on the combined use of AFP-L2 and AFP-L3 as a marker for trisomy 18 screening

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