[Clinical features and genetic analysis of a fetus with holoprosencephaly].

OBJECTIVE:To analyze the clinical features and pathogenesis of a fetus with holoprosencephaly. METHODS:The findings of prenatal ultrasonography was reviewed. Following elective abortion, whole exome sequencing (WES) was carried out to identify potential pathogenic variant. Copy number variants (CNVs) of the abortus and its parents were detected by low-depth high-throughput sequencing. The parents were also analyzed by chromosomal karyotyping. RESULTS:Prenatal ultrasound suggested that the fetus had holoprosencephaly. WES revealed that it had approximately 33 Mb deletion at chromosome 13 involving ZIC2, a haploid dose sensitive gene. The results of low-depth high-throughput sequencing confirmed that the fetus carried a de novo 32.32 Mb deletion at 13q31.1-34. Karyotyping analysis has excluded gross chromosomal aberration in both parents. CONCLUSION:The fetus was diagnosed with holoprosencephaly, which may be attributable to the 13q31.1-34 deletion involving the ZIC2 gene.