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Background: Pathogenic copy number variants (pCNVs) are associated with fetal ultrasound anomalies, which can be efficiently identified through chromosomal microarray analysis (CMA). The primary objective of the present study was to enhance understanding of the genotype–phenotype correlation in fetuses exhibiting absent or hypoplastic nasal bones using CMA. Methods: Enrolled in the present study were 94 cases of fetuses with absent/hypoplastic nasal bone, which were divided into an isolated absent/hypoplastic nasal bone group (n = 49) and a non‐isolated group (n = 45). All pregnant women enrolled in the study underwent karyotype analysis and CMA to assess chromosomal abnormalities in the fetuses. Results: Karyotype analysis and CMA detection were successfully performed in all cases. The results of karyotype and CMA indicate the presence of 11 cases of chromosome aneuploidy, with trisomy 21 being the most prevalent among them. A small supernumerary marker chromosome (sSMC) detected by karyotype analysis was further interpreted as a pCNV by CMA. Additionally, CMA detection elicited three cases of pCNVs, despite normal findings in their karyotype analysis results. Among them, one case of Roche translocation was identified to be a UPD in chromosome 15 with a low proportion of trisomy 15. Further, a significant difference in the detection rate of pCNVs was observed between non‐isolated and isolated absent/hypoplastic nasal bone (24.44% vs. 8.16%, p <.05). Conclusion: The present study enhances the utility of CMA in diagnosing the etiology of absent or hypoplastic nasal bone in fetuses. Further, isolated cases of absent or hypoplastic nasal bone strongly suggest the presence of chromosomal abnormalities, necessitating genetic evaluation through CMA. [ABSTRACT FROM AUTHOR]

Background: Congenital hemidysplasia with ichthyosiform nevus and limb defects (CHILD) syndrome is a rare X‐linked dominant, lethal male disorder caused by mutations to the NSDHL (NAD(P)H steroid dehydrogenase‐like protein) gene. It primarily exhibits strictly unilateral congenital hemidysplasia with ichthyosiform erythroderma and ipsilateral limb defects in female individuals. Methods: A Chinese couple suffering from recurrent spontaneous abortion in male fetuses was enrolled in this study. Chromosomal microarray analysis and whole‐exome sequencing were performed for genetic etiological diagnosis. Results: A 33‐year‐old pregnant woman with recurrent spontaneous abortion was experiencing her third pregnancy with a male embryo. In this pregnancy, a miscarriage occurred at a gestational age of 10+6 weeks with no copy number variants. However, a novel mutation c.790‐6C>T in the NSDHL gene was observed in the fetus through whole‐exome sequencing (WES). Parental verification indicated that the NSDHL gene variant was inherited from the mother. Additionally, the variant in the NSDHL gene was absent in her subsequent pregnancy with a female fetus. Conclusion: In this study, we detected c.790‐6C>T, a novel variant in the NSDHL gene that results in recurrent miscarriage in males. Our study may broaden the scope of research on the NSDHL gene in CHILD syndrome and strengthens the application value of WES for the genetic etiological identification of recurrent miscarriage. [ABSTRACT FROM AUTHOR]