ABC | Volume 111, Nº4, Octuber 2018

Original Article Luo et al Genetic testing analysis of fetuses with CHD Arq Bras Cardiol. 2018; 111(4):571-577 Table 1 – Genetic testing of 362 fetuses with congenital heart defects Etiology Classifications Numbers Aneuploidyn(111, 30.7%) Trisomy 18 61 Trisomy 21 31 Trisomy 13 19 Abnormality of chromosome structure (10, 2.8%) 46,X,i(X)(q10) 1 46,der(18)dup(18)(q11q22)del(18)(q22q23) 1 46,XY,r(13)(p13q34) 1 46,XY,der(21;21)(q10;q10),+21 1 46,XX,der(9)t(9;18)(p22;q21)mat 1 46,XY,del(10)(q11q22)dn 1 46,XY,6q-dn 1 46,XY,der(18)t(7;18)(q22;q23)mat 1 46,XX,del(5)(p13) 1 46,XY,der(5)t(5;12)(p13;p12)mat 1 CNVs (19, 5.2%) 15q13.2q13.3(30940398-32515681)x1 1 arr16p11.2(29614976-30199805)x1~2 1 arr16q21q24.3(63,863,382-90,130,136)x2~3 1 arr1q21.1q21.2(146,501,348-147,828,939)x1 1 arr3q21.1q29(123031042-198022430)x2~3 1 arr22q11.21(18877787-21458625)x1 1 arr22q11.21(18889490-21460220)x1 1 arr22q11.21(18895703-21928916)x1 1 arr 22q11.21(18844632-21462353)x1 1 arr 11q24.1q25(123615329-1349444006)x1 1 arr10q26.13q26.3 (126254468-135430043)x3, arr11q24.1q25(122805910-134944006)x1 1 arr 10p15.1p12.31(6085312-21544231)x1 1 arr 5q11.2q12.1(56368573-61428613)x1 1 arr21q11.2 q21.1(14687571-18341062)x1 1 arr22q11.21(21050552-21811991)x1 1 arr22q11.21(20740778-21445064)x1 1 arr22q11.21(18895703-21452237)x1 1 arr11q23.3q25(116728277-134944006)x3, arr22q11.1q11.21(16079545-20306993)x3 1 arr5p15.33p15.1(354051-17484038)x1, 5q34q35.3(165731079-180705539)x3 1 CNVs: copy-number variations. with mothers (including the rubella virus, other infections, radiation, drug use and environmental pollution) are reported to be associated with CHD. 5-7,27-29 However, the causes of most types of CHD are still poorly understood. In our study, 140 of 362 CHD fetuses were identified with clinically significant chromosomal abnormalities by karyotyping and CMA, with a detection rate of up to 38.7%. The positive rates of genetic testing in this study is far higher than previous reports in Chongqing, China 24 and the Netherlands. 30 This rate is similar to that of Brazilians. 31 Among the 140 chromosomal abnormalities, 111 (79.3%) were aneuploidy, of which trisomy 18 was the most common; 10 (7.1%) cases were abnormality of chromosome structure; and 19 (13.6%) cases were pathogenic or likely pathogenic CNVs. It is suggested that aneuploidy is the leading genetic cause of fetuses with CHD in our population. Given that G-banding can only reliably detect structural abnormalities > 10 Mb in size, 11 pathogenic CNVs may be missed by karyotyping but detected by CMA. On this basis, we estimate that the incremental yield of reportable CNVs with less than 10 Mb achieved by CMA was 3.0%. Complex multiple cardiac malformations have poor prognosis and heavily affect the quality of life of surviving infants, but cases such as mild tetralogy of fallot have 573