自行设计的多重链接探针扩增组合对多发畸形患儿的诊断价值

目的 尝试基于多重链接探针扩增（MLPA）技术设计的探针组合对多发畸形(MCA)患儿的诊断价值。方法 以临床发现≥2个的畸形表型患儿为病例，基于MLPA技术选择13种常见的MCA的关键基因和关键区域自行设计MLPA探针组合（SIGMA公司合成），以微阵列比较基因组杂交（aCGH）作为金标准，检验该探针组合的诊断准确性，再以MLPA探针组合行MCA临床诊断效果评估，对MLPA探针组合阳性的病例结合临床资料进行分析。结果 ①MLPA探针组合涉及的13种常见MCA，包括：21-三体综合征（KCNJ6、DYRK1A、RCAN1基因）、18-三体综合征（MC2R、DTNA、TCF4基因）、13-三体综合征（EDNRB、CENPJ、ERCC5、FREM2基因）、1p36区域缺失综合征（GABRD、SKI、TP73基因）、 5q35.3区域缺失综合征（Sotos综合征，NSD1基因）、CHARGE综合征（CHD7基因）、7q11.23区域缺失综合征（Williams Beuren综合征，CLIP2、ELN、LIMK1基因）；22q11.21区域缺失、重复综合征（DiGeorge综合征，SNAP29、TBX1、ZNF74基因）、17p11区域缺失综合征（Smith-Magenis综合征，RAI1、MFAP4基因）、5p15.2区域缺失综合征（Cri du Chat综合征, CTNND2、TERT基因）、15q11-13区域缺失综合征（Prader-Willi综合征，OCA2、UBE3A、GABRB3基因）、4p16.3区域缺失综合征（Wolf Hirschhorn综合征，MSX1、WHSC1、LETM1基因）、17q21.31区域缺失综合征（MAP3K14、MAPT基因）。②35例MCA中，aCGH检测阳性11例（31.4%），共诊断9种；MLPA探针组合检测阳性6例（17.1%），共诊断4种；MLPA组合探针检测阳性的6例微缺失和重复与11例aCGH检测阳性一致，6例MLPA探针组合检测阳性的变异位点均位于设计的MLPA探针组合中，122例临床MCA中，MLPA探针组合检测阳性21例（17.2%），诊断6种。③在157例MCA患儿中，应用MLPA探针组合共诊断阳性病例27例，共检出7种（53.8%），分别为21-三体综合征8例，18-三体综合征1例，5p15区域缺失综合征3例，22q11区域重复综合征1例、缺失综合征9例，5q35区域缺失综合征1例，15q11-q13区域缺失综合征3例，7q11.23区域微缺失综合征1例。结论 自行设计合成的MLPA探针组合对非典型临床表型的MCA病例有较好的诊断价值。

The diagnostic value of a self-designed multiplex ligation-dependent probe set for multiple congenital anomalies in children

Objective Using a self-designed MLPA probes set to detect chromosomal imbalances in patients with common multiple congenital anomalies(MCA) and to evaluate the value of the method in routine clinical examination. Methods Children with two or more abnormal phenotypes were taken as cases. The method of array comparative genomic hybridization (aCGH) was applied as the gold standard. The diagnostic accuracy of the self-designed MLPA probes was detected for 13 common MCA. After identification of the diagnostic accuracy of the MLPA probes set, patients with multiple genetic malformations were performed MLPA test, and the clinical data were collected for further analysis of the relationship between the clinical phenotype and the test results. Results ①13 common MCA included: 21-trisomy syndrome (KCNJ6, DYRK1A, RCAN1 gene), 18-trisomy syndrome (MC2R, DTNA, TCF4 gene), 13-trisomy syndrome (EDNRB, CENPJ, ERCC5, FREM2 gene), 1p36 region (1p-deletion syndrome, GABRD, SKI, TP73 gene), 5q35.3 region (Sotos syndrome, NSD1 gene), CHARGE syndrome (CHD7 gene), 7q11.23 region(Williams Beuren syndrome, CLIP2,ELN,LIMK1 gene), 22q11.21 region(DiGeorge syndrome,SNAP29,TBX1, ZNF74 gene ), 17p11 region (Smith-Magenis syndrome, RAI1, MFAP4 gene), 5p15.2 region (Cri Du Chat syndrome, CTNND2, TERT gene), 15q11-13 region (Prader-Willi syndrome, OCA2, UBE3A, GABRB3 gene), 4p16.3 region (Wolf-Hirschhorn syndrome, MSX1, WHSC1, LETM1 gene), 17q21.31 deletion syndrome (MAP3K14, MAPT gene). ②35 cases were performed aCGH and MLPA tests, 11 cases (31.4%) were detected abnormalities with the aCGH test, including 9 kinds of MCA; 6 cases (17.1%) with positive results of the MLPA test, including 4 kinds of MCA. Compared with the results of aCGH, the positive rate of the MLPA probe set was 100%, 6 cases with positive results of the MLPA test were all included in the self-designed probes. 21 positive cases (17.2%) were detected in 122 MCA cases, including 8 cases with 21-trisomy syndrome, 1 case with 18-trisomy syndrome,1 case with 5p15 microdeletion,8 cases with 22q11 deletion,2 cases with 15q11-q13 deletion, 1 cases with 7q11.23 microdeletion. Conclusion The self-designed MLPA probe set has a good diagnostic value for atypical clinical manifestations of MCA.