Objective To analyze the genetic etiology of a fetus with growth restriction,short long bones,small head circumference and enhanced kidney echoes,and explore the clinical significance of nonsense mutations in the NIPBL gene.Methods The clinical data of the fetus and his/her parents were collected.The variation sites of the NIPBL gene were verified by the chromosome karyotype a-nalysis of amniotic fluid,copy number variation detection in the human genome(CNV-seq),whole exome sequencing(WES)and Sanger sequencing.The databases such as China National Knowledge Infrastructure(CNKI),Wanfang Data,Wanfang Medical,and Pubmed were searched to further analyze the relationship between clinical symptoms and gene mutation sites in the fetus.Results The sequencing results showed that there was c.4555A>T heterozygous mutation in exon 21 of the NIPBL gene in the fetus,and that the same mutation was not detected in his/her parents.The above variation had not been included in databases such as Human Exon Data-base(ExAC),1000 genomes(1000G)and Genome Aggregation Database(gnomAD),and were comprehensively judged as harmful variation.Conclusion The detection of the nonsense variation,c.4555A>T(p.Lys1519?),in the NIPBL gene may provide experi-mental evidence for the prenatal diagnosis and fertility in this family.