Objective To define the nature and origin of a chromosomal aberration in a child with unexplained growth and development retardation,and to analyze its genotype G phenotype correlation.Methods A child who was admitted at the Department of Neurological Rehabilition of Maternal and Child Health Care Hospital of Longhua District,Shenzhen on July 9,2023 was selected as the study subject.Applying whole exome sequencing(WES)to analyze the child,and chromosomal karyotypes of the child and her parents were determined with routine G banding analysis.Traceability of non-invasive prenatal testing(NIPT)sequencing data from the mother during pregnancy was done for comparison.Results Clinically relevant pathogenic variants in monogenic disease susceptibility genes are not detected in patient with WES.Copy number variation(CNV)analysis revealed a 14.31 Mb deletion in the 18q22.1q23 region of the chromosome in the child,specifically seq[GRCh37]del(18)(q22.1q23);Chr18:g.63704349-7801648del.Karyotyping analysis suggested that the chromosomal karyotype of the child was 46,XX,del(18)(q22.1q23),whilst no karyotypic abnormality was found in either of his parents.By tracing NIPT sequencing data from the mother during pregnancy,there is a significant deviation in the Z value of the q22.1 q23 region of fetal chromosome 18,which is considered a fragment deletion.Conclusion 18q partial deletion carried by the child was confirmed.WES can clarify the CNV origin of chromosomal aberrations.Analysis of the correlation between genotype and phenotype can facilitate the clinical diagnosis and genetic counseling.
18q deletion syndromegrowth retardationwhole exome sequencingcopy number variation
NETL
NSTL
万方数据
