手足裂畸形(split-hand/split-foot malformation，SHFM)是一种严重的先天性肢端畸形，主要临床特征为并指(趾)畸形、指(趾)骨及掌(跖)骨发育不全。本研究报道了一例手足裂畸形胎儿，利用全外显子组测序技术结合Sanger测序的方法筛选候选基因变异位点，并为其家庭成员提供了胚胎植入前遗传学检测(preimplantation genetic testing，PGT)。基因检测结果显示胎儿WNT10B基因存在c.786G>A(p.Trp262*)纯合变异，其父母均为杂合突变携带者；PGT检测结果显示家系的2枚囊胚中，1枚基因型为突变杂合子，1枚基因型为突变纯合子，所有胚胎染色体均为二倍体，移植突变杂合子胚胎后成功达到单胎妊娠。本研究表明WNT10B基因纯合突变可能是导致该家系患手足裂畸形的原因，对于单基因病家系，在明确其致病突变后，通过胚胎植入前遗传学检测可有效避免患儿出生。

Split-hand/foot malformation is a serious congenital limb malformation characterized by syndactyly and underdevelopment of the phalanges and metatarsals. In this study, we reported a case of a fetus with hand-foot cleft deformity. Whole exome and Sanger sequencing were used to filter out candidate gene mutation sites and provide pre-implantation genetic testing(PGT) for family members. Genetic testing results showed that there was a homozygous mutation c.786G>A (p.Trp262*) in the fetal WNT10B, and both parents were carriers of heterozygous mutations. PGT results showed that out of the two blastocysts, one was a heterozygous mutant and the other was a homozygous mutant. All the embryos had diploid chromosomes. The heterozygous embryo was transferred, and a singleton pregnancy was successfully achieved. This study suggests that homozygous mutations in WNT10B are the likely cause of hand-foot clefts in this family. For families with monogenic diseases, preimplantation genetic testing can effectively prevent the birth of an affected child only after identifying the pathogenic mutation.