单核苷酸多态性微阵列和荧光原位杂交技术在Pallister-Killian综合征的产前诊断中的应用

Application of single nucleotide polymorphism microarray and fluorescence in situ hybridization analysis for the prenatal diagnosis of a case with Pallister-Killian syndrome

目的探讨Pallister-Killian综合征（Pallister-Killian syndrome，PKS）的临床特征及遗传学特点，分析Affymetrix CytoScan 750K SNP Array和荧光原位杂志（fluorescence in situ hybridization, FISH）技术在产前诊断中的应用价值。方法对1例36岁孕34＋2周高龄孕妇脐血标本进行G显带染色体核型分析，芯片技术鉴定异常片段来源，运用12pter/12qter探针FISH确认。结果胎儿脐血G显带染色体核型46，XY[77]/47，XY，＋mar[23]，出生后新生儿外周血芯片分析结果为arr[hg19] 12p13.33p11.1（173 786～34 835 641）×4，显示12号染色体12p13.33p11.1区段存在34.6 Mb的2次重复；FISH检测显示39%细胞有12号染色体短臂四体。结论通过结合临床特征，综合应用染色体G显带核型分析、FISH技术和芯片技术能准确确认染色体异常片段来源，有效诊断PKS患者。

ObjectiveTo explore the clinical and genetic characteristics of a case with Pallister-Killian syndrome （PKS）.MethodsChromosomal karyotype of umbilical cord blood sample derived from a 36-year-old pregnant woman was analyzed by G-banding analysis. After birth, the child was further analyzed with single nucleotide polymorphism microarray （SNP array） and fluorescence in situ hybridization （FISH） using 12pter/12qter probes. ResultsG-banding analysis showed that the fetus has a karyotype of 46, XY[77]/47, XY, ＋ mar[23]. After birth, Affymetrix CytoScan 750K array analysis showed a segmental tetrasomy of arr[hg19] 12p13.33p11.1（173 786 - 34 835 641）×4 and a 34.6 Mb repeat at 12p13.33p11.1 with in the neonate. FISH analysis confirmed that 39% of cells harbored the 12p tetrasomy. ConclusionCombined clinical examination, G-banded chromosomal karyotyping, FISH and microarray analysis can delineate the origin and fragments of small supernumerary marker chromosomes and diagnose PKS with precision.