Wang Junyu, Zhuang Jianlong, Jiang Yuying, Fu Wanyu, Wang Yuanbai
Prenatal Diagnosis Center, Quanzhou Women and Children's Health Care Hospital, Quanzhou, Fujian 362000, China.
Zhonghua Yi Xue Yi Chuan Xue Za Zhi. 2021 Oct 10;38(10):997-1001. doi: 10.3760/cma.j.cn511374-20201016-00724.
To apply combined non-invasive prenatal testing (NIPT), chromosomal karyotyping and chromosomal microarray for the screening and prenatal diagnosis of a fetus with supernumerary small marker chromosome (sSMC).
Standard NIFTY and full gene NIFTY kits were applied to detect free DNA (cfDNA) isolated from peripheral blood sample of a pregnancy woman. Amniocentesis was carried out for the woman for an abnormal NIPT result. G-banded karyotyping and single nucleotide polymorphism array (SNP array) were used to determine the karyotype and copy number variants in the fetus. The result was validated with a fluorescence in situ hybridization (FISH) assay.
Both the standard NIFTY and full gene NIFTY indicated abnormal dup(chr12:707 334-33 308 759), for which the T score value of copy number anomaly in full gene NIFTY is 6.823, which is higher than the standard NIFTY's T-score value of 3.9535. The two NIFTY results were both above the normal threshold ± 3. Conventional G-banding analysis of amniocytes showed that the fetus has a karyotype of 47,XY,+mar. SNP-array delineated duplication of 12p (arr [hg19]12p13.33p11.1 (173 786_34 385 641)× 4, which was verified by FISH. Based on the above results, the fetus was diagnosed as a novel case of Pallister-Killian syndrome.
NIPT has a certain value for the prenatal detection of PKS. Combined use of multiple techniques can facilitate delineation of the source of sSMC.
应用联合无创产前检测（NIPT）、染色体核型分析和染色体微阵列技术对携带额外小标记染色体（sSMC）的胎儿进行筛查和产前诊断。
应用标准NIFTY和全基因NIFTY试剂盒检测从孕妇外周血样本中分离的游离DNA（cfDNA）。因NIPT结果异常，对该孕妇进行了羊膜腔穿刺术。采用G显带核型分析和单核苷酸多态性阵列（SNP阵列）确定胎儿的核型和拷贝数变异。结果通过荧光原位杂交（FISH）检测进行验证。
标准NIFTY和全基因NIFTY均显示dup（chr12:707 334-33 308 759）异常，全基因NIFTY中拷贝数异常的T评分值为6.823，高于标准NIFTY的T评分值3.9535。两个NIFTY结果均高于正常阈值±3。羊水细胞的常规G显带分析显示胎儿核型为47,XY,+mar。SNP阵列显示12p重复（arr [hg19]12p13.33p11.1（173 786_34 385 641）×4），经FISH验证。基于上述结果，该胎儿被诊断为帕利斯特-基利安综合征的新病例。
NIPT对PKS的产前检测具有一定价值。多种技术联合使用有助于明确sSMC的来源。
