Search

With the advancements in prenatal diagnostics, genome sequencing is now incorporated into clinical use to maximize the diagnostic yield following uninformative conventional tests (karyotype and chromosomal microarray analysis). Hong Kong started publicly funded prenatal genomic sequencing as a sequential test in the investigation of fetal structural anomalies in April 2021. The objective of the study was to evaluate the clinical performance and usefulness of this new service over one year. We established a web-based multidisciplinary team to facilitate case selection among the expert members. We retrospectively analyzed the fetal phenotypes, test results, turnaround time and clinical impact in the first 15 whole exome sequencing and 14 whole genome sequencing. Overall, the molecular diagnostic rate was 37.9% (11/29). De novo autosomal dominant disorders accounted for 72.7% (8/11), inherited autosomal recessive disorders for 18.2% (2/11), and inherited X-linked disorders for 9.1% (1/11). The median turnaround time for ongoing pregnancy was 19.5 days (range, 13-31 days). Our study showed an overall clinical impact of 55.2% (16/29), which influenced reproductive decision-making in four cases, guided perinatal management in two cases and helped future family planning in ten cases. In conclusion, our findings support the important role of genome sequencing services in the prenatal diagnosis of fetal structural anomalies in a population setting. It is important to adopt a multidisciplinary team approach to support the comprehensive genetic service.

In this first Asian study, the decision outcomes (decision conflict, decision regret, and anxiety) of 262 pregnant women offered noninvasive prenatal test (NIPT) for high-risk Down screening results were assessed. Decision conflict was experienced by 3.5% and level of decisional regret low (mean score 15.7, 95%CI 13.2-18.3). All 13 cases of decisional regret were NIPT acceptors. Elevated anxiety was experienced by 55.9% at the time of decision making about NIPT and persistent in 30.3%. Insufficient knowledge about NIPT was associated with elevated anxiety at decision making (p = .011) and with decisional regret (p = .016). Decisional regret was associated with prolonged anxiety (p = .010).

Objective: To evaluate the local incidence of orofacial cleft (OFC) encountered in fetal morphology scan and prenatal diagnosis, genetic etiology of fetuses with or without other structural abnormalities, and their pregnancy outcomes. Design: Retrospective cohort study. Setting: Two maternal fetal medicine units, tertiary hospitals, Hong Kong. Participants: All pregnant women with antenatal diagnosis of fetal OFC between January 2016 and December 2020 (N = 66). Results: OFC has an incidence of 0.13% among pregnancies in Hong Kong and 28.8% (19/66) were syndromic cleft that exhibited other fetal structural anomalies. There were 55 cases (84.6%) who opted for invasive prenatal diagnostic testing. Genetic defects were identified in 25.8% (17/66) of this cohort, including 14 pathogenic variants. The detection rate in the syndromic cases is 68.4% (13/19) which was significantly higher than 8.5% (4/47) among non-syndromic cases. Aneuploidies would be the most common cause, accounting for 9.1% (6/66). Chromosomal microarray analysis (CMA) provided an incremental diagnostic yield of 6.1% compared to conventional karyotyping. A total of 29 live births including 3 cases of a variant of uncertain significance and 26 cases without genetic abnormalities detected have continued pregnancy to birth. There were 87.5% (21/24) without detectable pathogenic genetic abnormality reported good long-term outcomes. The chance of OFC fetuses having a good long-term outcome was significantly higher if no genomic variant was detected (P <.001). Conclusions: Invasive prenatal tests with CMA should be offered to pregnancies with OFC regardless of the type. It has provided incremental diagnostic yield over conventional karyotyping and helped in prenatal and genetic counseling. A negative result in non-syndromic OFC favors couples to keep the pregnancy. [ABSTRACT FROM AUTHOR]

Fetal structural congenital abnormalities (SCAs) complicate 2–3% of all pregnancies. Whole-exome sequencing (WES) has been increasingly adopted prenatally when karyotyping and chromosomal microarray do not yield a diagnosis. This is a retrospective cohort study of 104 fetuses with SCAs identified on antenatal ultrasound in Hong Kong, where whole exome sequencing is performed. Molecular diagnosis was obtained in 25 of the 104 fetuses (24%). The highest diagnostic rate was found in fetuses with multiple SCAs (29.2%), particularly those with involvement of the cardiac and musculoskeletal systems. Variants of uncertain significance were detected in 8 out of the 104 fetuses (7.7%). Our study shows the utility of WES in the prenatal setting, and the extended use of the technology would be recommended in addition to conventional genetic workup. [ABSTRACT FROM AUTHOR]