Ultrasound findings and genetic diagnosis of 95 fetuses with complex talipes equinovarus
10.3760/cma.j.cn113903-20230831-00172
- VernacularTitle:95例复杂型马蹄内翻足胎儿的超声表现及其遗传学诊断结果
- Author:
Yuze WANG
1
;
Ling LIU
;
Chunshuang ZHANG
;
Yunxiao ZHI
;
Jinjin MA
;
Guomei CHENG
Author Information
1. 郑州大学第三附属医院医学遗传与产前诊断中心，郑州 450000
- Keywords:
Talipes equinovarus;
Ultrasonography, prenatal;
Karyotyping;
DNA copy number variations
- From:
Chinese Journal of Perinatal Medicine
2024;27(5):379-386
- CountryChina
- Language:Chinese
-
Abstract:
Objective:To investigate the ultrasonographic features and genetic etiology of complex talipes equinovarus (TE) in fetuses.Methods:This retrospective study enrolled 95 cases of complex TE (TE complicated by other abnormalities) who were diagnosed by prenatal ultrasound in the Third Affiliated Hospital of Zhengzhou University from March 2018 to December 2022. Chromosome karyotype analysis and/or chromosomal microarray analysis (CMA) [or copy number variation-sequencing (CNV-seq)] were performed on all cases for prenatal genetic diagnosis and those with normal results were further tested by whole exome sequencing (WES). Prenatal ultrasonographic and genetic features of complex TE in fetuses were summarized. Complicated abnormalities in the fetuses were classified into nine categories according to the involved system or site and based on each category these subjects were divided into with or without the corresponding complicated abnormalities groups. Besides, these cases were also divided into single-system and multi-system abnormality groups based on the number of involved systems or sites of complicated abnormalities. The detection rates of WES abnormality (pathogenic or likely pathogenic variants) and the overall detection rate of genetic abnormality [karyotype abnormality detected by chromosome karyotype analysis, pathogenic or likely pathogenic copy number variations (CNVs) detected by CMA (or CNV-seq), and pathogenic or likely pathogenic variation detected by WES] were compared between different groups using Chi-square test or Fisher's exact test. Results:Abnormal chromosome karyotypes were identified in 10 (24.4%) of 41 cases receiving chromosome karyotype analysis, pathogenic and likely pathogenic CNVs were found in seven (7.6%) of 92 cases by CMA (or CNV-seq). WES was performed on 37 cases with negative results of chromosomal karyotype analysis and CMA (or CNV-seq) and the detection rate of pathogenic and likely pathogenic variants was 43.2% (16/37). The detection rate of WES abnormality was higher in the fetuses with musculoskeletal abnormalities than in those without the abnormalities [71.4% (15/21) vs. 1/16, Fisher's exact test, P<0.001], while in those with other postural abnormalities was higher than that in the group without other postural abnormalities [12/16 vs. 19.0% (4/21), Fisher's exact test, P=0.001]. The genetic causes of complex TE were identified in 34.7% (33/95) of the fetuses by the sequential genetic diagnosis using chromosome karyotype analysis, CMA (or CNV-seq), and WES. The overall detection rate of genetic abnormality was higher in the group with multi-system abnormality than in the group with single-system abnormality [48.9% (22/45) vs. 22.0% (11/50), χ2=7.55, P=0.006], in the group with musculoskeletal system abnormalities and without [46.8% (22/47) vs. 22.9% (11/48), χ2=5.98, P=0.014], and in the group with other postural abnormality and without [47.2% (17/36) vs. 27.1% (16/59), χ2=3.99, P=0.046]. Nine cases that were considered isolated TE on initial ultrasound were corrected to a complex diagnosis on subsequent ultrasound examinations. Of all the involved system or site, the neurologic abnormalities were the most diverse (13 kinds) and had a diversity of ultrasound presentations. Conclusions:Genetic diagnosis should be performed when prenatal ultrasound suggests fetal complex TE. WES is conducive to improving the prenatal detection rate of monogenic diseases, especially in fetuses complicated by musculoskeletal abnormalities. Isolated TE fetuses require serial ultrasound examinations to correct the diagnosis in time and genetic testing should be performed if necessary. Additional attention should be paid to the TE fetus for comorbid neurologic abnormalities at the time of ultrasonography to rule out TE as an intrauterine harbinger of neuromuscular disease.
