摘要:
Objective To explore the candidate disease causing gene for a case with floppy infant syndrome (FIS).Methods Single nucleotide polymorphism array (SNP array) was used for analyzing the whole genome copy number mutations in the proband.Multiple PCR combined with denaturing high performance liquid chromatography (DHPLC) was employed to verify the suspected mutations in the proband and his family members.Results A large duplication arr [hg19] Xq13.1:67 987 646-73 805 828,which spans approximately 5.818182 Mb and encompasses 66 known genes,was identified in the proband.The multiple PCR-DHPLC assay confirmed duplication of HDAC8,PHKA1,TAF1,DLG3,KIF4A,IGBP1,PJA1 and SLC16A2 genes in the proband.His mother and grandmother both had duplication of the above genes in one X chromosome,but his aunt had not.Conclusion The large Xq13.1 duplication identified by the SNP array probably underlies the FIS in this family.For its high-throughput,high resolution and capacity of automation,SNP array has provided a first line method for the genetic testing for infants featuring developmental delay with unknown reason,mental retardation,autism,multiple malformation and FIS.%目的 探讨1例松软婴儿综合征(floppy infant syndrome,FIS)家系的侯选致病基因.方法 用单核苷酸多态性微阵列(single nucleotide polymorphism array,SNP-array)芯片对患儿进行全基因组拷贝数扫描,之后用PCR和变性高效液相色谱(denaturing high performance liquid chromatography,DHPLC)在患儿及其家系成员中验证芯片检测的结果.结果 患儿的检测结果为arr[hg19] Xq13.1:67 987 646-73 805 828,即存在5.818 182 Mb的大片段重复,该区域共涉及66个已知基因.DHPLC检测证实患儿重复区内的8个基因(PJA1、IGBP1、KIF4A、DLG3、TAF1、HDAC8、PHKA1和SLC16A2)均存在重复,其母亲和外祖母仅一条X染色体携带上述重复,其姨妈则未携带上述重复.结论 Xq13.1区的大片段重复可能是患儿的遗传学病因.SNP-array检测具有通量高、分辨率高、自动化操作的优势,可作为不明原因发育迟缓、智力低下、自闭症、多发畸形及FIS的首选检测方法.