1.Clinical phenotype and genotypic analysis of a four-generation Chinese pedigree affected with Stickler syndrome and a literature review
Wenjun HE ; Fang TANG ; Fan JIANG ; Ziman CHEN ; Yan LU ; Yutong NI ; Jianying ZHOU ; Dongzhi LI
Chinese Journal of Medical Genetics 2025;42(6):684-690
Objective:To carry out genetic testing and clinical phenotypic characterization on a four-generation Chinese pedigree affected with Stickler syndrome type I and explore its genotype-phenotype correlation.Methods:A child presented at the Second Affiliated Hospital of Guangzhou University of Traditional Chinese Medicine in February 2023 for micrognathia, glossoptosis and cleft palate and his family members were selected as the study subjects. Clinical data were collected from the affected members, and peripheral blood samples were obtained from 17 participants (4 patients and 13 asymptomatic individuals). Whole exome sequencing (WES) was carried out. Candidate variant was verified by Sanger sequencing. Genotype-phenotype correlations were analyzed by integrating the sequencing data with evidence from existing literature. This study has bee granted by the Ethics Committee of Guangdong Provincial Hospital of Traditional Chinese Medicine and Guangzhou Women and Children′s Medical Center (Ethics No.: 2022-406B00).Results:The four-generation pedigree has comprised 19 members. In addition to the proband, 5 affected individuals had manifested high myopia, congenital cataracts, and progressive vision loss. Two deceased members reportedly exhibited similar ocular manifestations. Among the four living patients, two had developed retinal detachment, while two others presented with chronic joint pain onset between 35 ~ 40 years of age. One patient required hip replacement surgery at age 42 secondary to femoral head necrosis. The proband, the youngest affected member, exhibited characteristic phenotypes including congenital micrognathia and cleft palate, consistent with Pierre-Robin syndrome. Genetic analysis revealed a heterozygous nonsense mutation in COL2A1 (NM_001844.5: c. 2668C>T; p. Gln890Ter) segregating with the disease in all four symptomatic patients. This variant was absent in asymptomatic family members and unaffected controls. While the mutation is listed in ClinVar, no clinical case reports has associated it with this phenotypic spectrum. It was not observed in population databases (gnomAD v4.1.0, 1000 Genomes Project, or ExAC), supporting its potential pathogenicity. Conclusion:This study has diagnosed a four-generation Chinese pedigree with Stickler syndrome type I attributed to the pathogenic COL2A1 variant c. 2668C>T (p.Gln890Ter), which is a rare nonsense mutation associated with ocular predominance and variable skeletal involvement. Notably, this family exhibited marked clinical heterogeneity despite sharing the identical genotype, which highlighted challenges in phenotype-genotype correlation. The autosomal dominant transmission pattern observed in this pedigree has provided critical insights into COL2A1-related collagenopathies and underscored the necessity of ultrasonographic monitoring for ocular anomalies in prenatal diagnostics. Above findings have advanced our understanding of pleiotropic effects in type Ⅱ collagen disorders and lay the foundation for precision-based genetic counseling, enabling targeted cascade screening and implementation of tertiary prevention strategies against congenital disabilities in high-risk families.
2.Maternal complex chromosomal rearrangement leading to fetal chromosomal structural abnormalities: an analysis of three cases
Yingying SHEN ; Dongzhi LI ; Wei LI ; Fei LI ; Cuixing YI ; Simin YUAN
Chinese Journal of Perinatal Medicine 2025;28(5):414-418
Objective:To summarize the clinical features and genetic effects of cases of fetal chromosomal structural abnormalities caused by maternal complex chromosomal rearrangements (CCR).Methods:Three female CCR carriers referred to the Prenatal Diagnostic Center at Guangzhou Women and Children's Medical Center, Guangzhou Medical University between October 2023 and June 2024 were retrospectively enrolled. Genetic analyses included chromosomal karyotyping, chromosomal microarray analysis (CMA), and low-coverage whole-genome copy number variation (CNV) sequencing. Clinical features of the three cases with fetal chromosomal structural abnormalities caused by maternal CCR were systematically reviewed using descriptive statistics.Results:(1) Case 1: CNV sequencing identified an 11.95 Mb duplication at 1q43q44 region of chromosome (CNV of uncertain significance) and a 36.09 Mb deletion at 5p15.33p13.2 region of chromosome (pathogenic CNV) in the fetus (maternally inherited). Maternal karyotype was 46,XX,t(1;8;3;5)(q43;q22.1;q26.2;p13.2). The pregnancy was terminated after genetic counseling. (2) Case 2: Maternal karyotype 46,XX,t(3;20)(p25;q13.1),t(6;12)(q25.2;q21.2),ins(11;14)(q23;q24q13) was transmitted to the fetus [46,XX,ins(11;14)(q23;q24q13)mat]. CMA of the fetus showed no abnormalities and the pregnancy was continued after genetic counseling. (3) Case 3: CMA of the products of conception revealed a 71.59 Mb duplication at 2p24.3p11.2 (pathogenic CNV). Maternal karyotype was 46,XX,der(2)t(2;3)(q21;q23)ins(11;2)(p13;p24p11.2),der(3)t(2;3),der(11)ins(11;2). The abnormal chromosome 2 segment in products of conception was maternally inherited.Conclusions:All three cases of fetal/abortus chromosomal abnormalities originated from maternal CCR. Early combined cytogenetic and molecular prenatal diagnosis is critical for CCR carriers during pregnancy.
3.Genetic findings and pregnancy outcomes in fetuses with omphalocele: an analysis of 502 cases
Wei HE ; Li ZHEN ; Pingshan PANG ; Qi YANG ; Peng HUANG ; Feiwen LONG ; Linlin WANG ; Dongzhi LI
Chinese Journal of Perinatal Medicine 2025;28(9):762-769
Objective:To investigate genetic findings and pregnancy outcomes in fetuses with omphalocele.Methods:This retrospective study analyzed data from 502 fetuses with prenatally diagnosed omphalocele who underwent genetic testing at Guangzhou Women and Children's Medical Center and Maternal and Child Health Hospital of Guangxi Zhuang Autonomous Region between January 2014 and March 2024. Testing methods included karyotyping, chromosomal microarray analysis (CMA), methylation-specific multiplex ligation-dependent probe amplification, and whole-exome sequencing (WES). Cases were categorized as non-isolated ( n=340) or isolated ( n=162) based on ultrasound findings. Differences in genetic abnormality detection rates and pregnancy outcomes were analyzed using Mann-Whitney U test, independent samples t-test, and Chi-square test (or Fisher's exact test). Results:Among 502 fetuses, karyotyping plus CMA detected chromosomal abnormalities in 223 cases (44.4%, 223/502), including trisomy 18 (57.0%, 127/223) and trisomy 13 (23.3%, 52/223). CMA additionally identified nine pathogenic copy number variations (1.8%, 9/502) and five uniparental disomies (1.0%, 5/502), increasing the total diagnostic yield from 44.4% to 47.2%. The genetic abnormality rate was significantly lower in isolated (14.8%, 24/162) versus non-isolated omphalocele (64.7%, 220/340) ( χ2=109.34, P<0.001). WES detected variants in nine of 16 karyotype/CMA-negative cases, including five pathogenic variants involving PIK3CA and CDKN1C. Eight imprinting disorders (1.6%, 8/502) were identified, including five Beckwith-Wiedemann syndrome cases. Among 499 cases with follow-up, 401 (80.4%, 401/499) underwent pregnancy termination. Live birth rate was higher in isolated versus non-isolated groups [42.5% (69/162) vs. 8.5% (29/340), χ2=77.67, P<0.001]. Three cases were lost to follow-up. The one-year survival rate was 93.9% (92/98) in live-born infants. Conclusion:Aneuploidy (particularly trisomy 18) is the primary genetic etiology of omphalocele. CMA and WES significantly improve diagnostic yield. Isolated omphalocele has a more favorable prognosis, while non-isolated cases show significantly higher genetic abnormality rates. A stratified testing strategy is recommended: karyotyping plus CMA for isolated cases and prioritization of WES for multiple anomalies.
4.Prevalence of Schistosoma japonicum infections in wild rodents in key areas during the elimination phase
Chao LÜ ; Xiaojuan XU ; Jiajia LI ; Ting FENG ; Hai ZHU ; Yifeng LI ; Ling XU ; Zhihong FENG ; Huiwen JIANG ; Xiaoqing ZOU ; Wenjun WEI ; Zhiqiang QIN ; Yang HONG ; Shiqing ZHANG ; Jing XU
Chinese Journal of Schistosomiasis Control 2025;37(5):475-481
Objective To investigate the prevalence of Schistosoma japonicum infections in wild rodents in schistosomiasis-endemic areas of China, so as to provide insights into formulation of technical guidelines for monitoring of and the precise control strategy for S. japonicum infections in wild rodents during the elimination phase. Methods Two administrative villages where schistosomiasis was historically highly prevalent were selected each from Dongzhi County, Anhui Province, and Duchang County, Jiangxi Province as study villages. Wild rodents were captured from study villages with baited traps or cages at night in June and September, 2021. The number of rodents captured was recorded, and the rodent species was characterized based on morphologi-cal characteristics. Liver tissues were sampled from captured rodents for macroscopical observation of the presence of egg granu- lomas, and S. japonicum infection was detected simultaneously using liver tissue homogenate microscopy, examinations of mesenteric tissues for parasites, and modified Kato-Katz thick smear technique (Kato-Katz technique). A positive S. japonicum infection was defined as detection of S. japonicum eggs or adult worms by any of these methods. The rate of wild rodent capture and prevalence of S. japonicum infections in wild rodents were compared in different study villages and at different time periods, and the detection of S. japonicum infections in wild rodents was compared by different assays. Results The overall rate of wild ro- dent capture was 8.28% (237/2 861) in Dongzhi County, and the wild rodent capture rates were 9.24% (133/1 439) and 7.31% (104/1 422) in two study villages (χ2 = 3.503, P = 0.061), and were 8.59% (121/1 409) and 7.99% (116/1 452) in June and September, 2021, respectively (χ2 = 0.337, P = 0.561). The overall rate of wild rodent capture was 3.72% (77/2 072) in Duchang County, and the wild rodent capture rates were 6.91% (67/970) and 0.91% (10/1 102) in two study villages (χ2 = 51.901, P < 0.001), and were 4.13% (39/945) and 3.37% (38/1 127) in June and September, 2021, respectively (χ2 = 0.815, P = 0.365). Rattus norvegicus was the predominant rodent species captured in both counties, accounting for 70.04% (166/237) of all captured wild rodents in Dongzhi County and 88.31% (68/77) in Duchang County. No S. japonicum infection was detected in wild rodents captured in Duchang County. Nevertheless, the overall prevalence of S. japonicum infections was 51.05% (121/237) in wild rodents captured in Dongzhi County, with prevalence rates of 50.38% (67/133) and 51.92% (54/104) in two study villages (χ2 = 0.098, P = 0.755), and 54.31% (63/116) and 47.93% (58/121) in September and June, 2021, respectively (χ2 = 0.964, P = 0.326). Of 237 wild rodents captured in Dongzhi County, there were 140 (59.07%) rodents with visible hepatic egg granulomas, 117 (49.47%) tested positive for S. japonicum eggs by liver tissue homogenate microscopy, 34 (14.35%) tested positive for S. japonicum eggs with Kato-Katz technique; however, no adult S. japonicum worms were detected in mesenteric tissues. In addition, hepatic egg granulomas were found in all wild rodents tested positive for S. japonicum eggs with liver tissue homogenate microscopy. Conclusions The rate of wild rodent capture and prevalence of S. japonicum infection in wild rodents vary greatly in schistosomiasis-endemic areas of China, and the prevalence of S. japonicum infection is slightly higher in wild rodents captured in autumn than in summer. Liver tissue is recommended as the preferred sample for surveillance of S. japonicum infection in wild rodents, and a combination of macroscopical observation of hepatic egg granulomas and liver tissue homogenate microscopy may be a standard method for surveillance of S. japonicum infection in wild rodents.
5.Clinical phenotype and genotypic analysis of a four-generation Chinese pedigree affected with Stickler syndrome and a literature review.
Wenjun HE ; Fang TANG ; Fan JIANG ; Ziman CHEN ; Yan LU ; Yutong NI ; Jianying ZHOU ; Dongzhi LI
Chinese Journal of Medical Genetics 2025;42(6):684-690
OBJECTIVE:
To carry out genetic testing and clinical phenotypic characterization on a four-generation Chinese pedigree affected with Stickler syndrome type I and explore its genotype-phenotype correlation.
METHODS:
A child presented at the Second Affiliated Hospital of Guangzhou University of Traditional Chinese Medicine in February 2023 for micrognathia, glossoptosis and cleft palate and his family members were selected as the study subjects. Clinical data were collected from the affected members, and peripheral blood samples were obtained from 17 participants (including 4 patients and 13 asymptomatic individuals). Whole exome sequencing (WES) was carried out. Candidate variant was verified by Sanger sequencing. Genotype-phenotype correlation was analyzed by integrating the sequencing data with evidence from existing literature. This study has bee granted by the Ethics Committee of Guangdong Provincial Hospital of Traditional Chinese Medicine and Guangzhou Women and Children's Medical Center (Ethics No.: 2022-406B00).
RESULTS:
The four-generation pedigree has comprised 19 members. In addition to the proband, 5 affected individuals had manifested with high myopia, congenital cataracts, and progressive vision loss. Two deceased members reportedly exhibited similar ocular manifestations. Among the four living patients, two had developed retinal detachment, while two others presented with chronic joint pain onset between 35 ~ 40 years of age. One patient required hip replacement surgery at age 42 secondary to femoral head necrosis. The proband, the youngest affected member, exhibited characteristic phenotypes including congenital micrognathia and cleft palate, consistent with Pierre-Robin syndrome. Genetic analysis revealed a heterozygous nonsense mutation in COL2A1 (NM_001844.5: c.2668C>T; p.Gln890Ter) segregating with the disease in all four symptomatic patients. This variant was absent in asymptomatic family members and unaffected controls. While the mutation is listed in ClinVar, no clinical case report has associated it with this phenotypic spectrum. It was not recorded in population databases (gnomAD v4.1.0, 1000 Genomes Project, or ExAC), supporting its potential pathogenicity.
CONCLUSION
This study has diagnosed a four-generation Chinese pedigree with Stickler syndrome type I attributed to the pathogenic COL2A1 variant c.2668C>T (p.Gln890Ter), which is a rare nonsense mutation associated with ocular predominance and variable skeletal involvement. Notably, this family exhibited marked clinical heterogeneity despite sharing the identical genotype, which highlighted the challenges in phenotype-genotype correlation. The autosomal dominant transmission pattern observed in this pedigree has provided critical insights into COL2A1-related collagenopathies and underscored the necessity of ultrasonographic monitoring for ocular anomalies during prenatal diagnosis. Above findings have advanced our understanding of the pleiotropic effects in type Ⅱ collagen disorders and laid the foundation for precision-based genetic counseling, enabling targeted cascade screening and implementation of tertiary prevention strategies against congenital disabilities for high-risk families.
Adolescent
;
Adult
;
Child
;
Child, Preschool
;
Female
;
Humans
;
Male
;
Middle Aged
;
Arthritis/genetics*
;
Collagen Type II/genetics*
;
Connective Tissue Diseases/genetics*
;
Exome Sequencing
;
Genetic Association Studies
;
Genotype
;
Hearing Loss, Sensorineural/genetics*
;
Mutation
;
Pedigree
;
Phenotype
;
Retinal Detachment/genetics*
;
East Asian People/genetics*
6.Clinical phenotype and genotypic analysis of a four-generation Chinese pedigree affected with Stickler syndrome and a literature review
Wenjun HE ; Fang TANG ; Fan JIANG ; Ziman CHEN ; Yan LU ; Yutong NI ; Jianying ZHOU ; Dongzhi LI
Chinese Journal of Medical Genetics 2025;42(6):684-690
Objective:To carry out genetic testing and clinical phenotypic characterization on a four-generation Chinese pedigree affected with Stickler syndrome type I and explore its genotype-phenotype correlation.Methods:A child presented at the Second Affiliated Hospital of Guangzhou University of Traditional Chinese Medicine in February 2023 for micrognathia, glossoptosis and cleft palate and his family members were selected as the study subjects. Clinical data were collected from the affected members, and peripheral blood samples were obtained from 17 participants (4 patients and 13 asymptomatic individuals). Whole exome sequencing (WES) was carried out. Candidate variant was verified by Sanger sequencing. Genotype-phenotype correlations were analyzed by integrating the sequencing data with evidence from existing literature. This study has bee granted by the Ethics Committee of Guangdong Provincial Hospital of Traditional Chinese Medicine and Guangzhou Women and Children′s Medical Center (Ethics No.: 2022-406B00).Results:The four-generation pedigree has comprised 19 members. In addition to the proband, 5 affected individuals had manifested high myopia, congenital cataracts, and progressive vision loss. Two deceased members reportedly exhibited similar ocular manifestations. Among the four living patients, two had developed retinal detachment, while two others presented with chronic joint pain onset between 35 ~ 40 years of age. One patient required hip replacement surgery at age 42 secondary to femoral head necrosis. The proband, the youngest affected member, exhibited characteristic phenotypes including congenital micrognathia and cleft palate, consistent with Pierre-Robin syndrome. Genetic analysis revealed a heterozygous nonsense mutation in COL2A1 (NM_001844.5: c. 2668C>T; p. Gln890Ter) segregating with the disease in all four symptomatic patients. This variant was absent in asymptomatic family members and unaffected controls. While the mutation is listed in ClinVar, no clinical case reports has associated it with this phenotypic spectrum. It was not observed in population databases (gnomAD v4.1.0, 1000 Genomes Project, or ExAC), supporting its potential pathogenicity. Conclusion:This study has diagnosed a four-generation Chinese pedigree with Stickler syndrome type I attributed to the pathogenic COL2A1 variant c. 2668C>T (p.Gln890Ter), which is a rare nonsense mutation associated with ocular predominance and variable skeletal involvement. Notably, this family exhibited marked clinical heterogeneity despite sharing the identical genotype, which highlighted challenges in phenotype-genotype correlation. The autosomal dominant transmission pattern observed in this pedigree has provided critical insights into COL2A1-related collagenopathies and underscored the necessity of ultrasonographic monitoring for ocular anomalies in prenatal diagnostics. Above findings have advanced our understanding of pleiotropic effects in type Ⅱ collagen disorders and lay the foundation for precision-based genetic counseling, enabling targeted cascade screening and implementation of tertiary prevention strategies against congenital disabilities in high-risk families.
7.Maternal complex chromosomal rearrangement leading to fetal chromosomal structural abnormalities: an analysis of three cases
Yingying SHEN ; Dongzhi LI ; Wei LI ; Fei LI ; Cuixing YI ; Simin YUAN
Chinese Journal of Perinatal Medicine 2025;28(5):414-418
Objective:To summarize the clinical features and genetic effects of cases of fetal chromosomal structural abnormalities caused by maternal complex chromosomal rearrangements (CCR).Methods:Three female CCR carriers referred to the Prenatal Diagnostic Center at Guangzhou Women and Children's Medical Center, Guangzhou Medical University between October 2023 and June 2024 were retrospectively enrolled. Genetic analyses included chromosomal karyotyping, chromosomal microarray analysis (CMA), and low-coverage whole-genome copy number variation (CNV) sequencing. Clinical features of the three cases with fetal chromosomal structural abnormalities caused by maternal CCR were systematically reviewed using descriptive statistics.Results:(1) Case 1: CNV sequencing identified an 11.95 Mb duplication at 1q43q44 region of chromosome (CNV of uncertain significance) and a 36.09 Mb deletion at 5p15.33p13.2 region of chromosome (pathogenic CNV) in the fetus (maternally inherited). Maternal karyotype was 46,XX,t(1;8;3;5)(q43;q22.1;q26.2;p13.2). The pregnancy was terminated after genetic counseling. (2) Case 2: Maternal karyotype 46,XX,t(3;20)(p25;q13.1),t(6;12)(q25.2;q21.2),ins(11;14)(q23;q24q13) was transmitted to the fetus [46,XX,ins(11;14)(q23;q24q13)mat]. CMA of the fetus showed no abnormalities and the pregnancy was continued after genetic counseling. (3) Case 3: CMA of the products of conception revealed a 71.59 Mb duplication at 2p24.3p11.2 (pathogenic CNV). Maternal karyotype was 46,XX,der(2)t(2;3)(q21;q23)ins(11;2)(p13;p24p11.2),der(3)t(2;3),der(11)ins(11;2). The abnormal chromosome 2 segment in products of conception was maternally inherited.Conclusions:All three cases of fetal/abortus chromosomal abnormalities originated from maternal CCR. Early combined cytogenetic and molecular prenatal diagnosis is critical for CCR carriers during pregnancy.
8.Genetic findings and pregnancy outcomes in fetuses with omphalocele: an analysis of 502 cases
Wei HE ; Li ZHEN ; Pingshan PANG ; Qi YANG ; Peng HUANG ; Feiwen LONG ; Linlin WANG ; Dongzhi LI
Chinese Journal of Perinatal Medicine 2025;28(9):762-769
Objective:To investigate genetic findings and pregnancy outcomes in fetuses with omphalocele.Methods:This retrospective study analyzed data from 502 fetuses with prenatally diagnosed omphalocele who underwent genetic testing at Guangzhou Women and Children's Medical Center and Maternal and Child Health Hospital of Guangxi Zhuang Autonomous Region between January 2014 and March 2024. Testing methods included karyotyping, chromosomal microarray analysis (CMA), methylation-specific multiplex ligation-dependent probe amplification, and whole-exome sequencing (WES). Cases were categorized as non-isolated ( n=340) or isolated ( n=162) based on ultrasound findings. Differences in genetic abnormality detection rates and pregnancy outcomes were analyzed using Mann-Whitney U test, independent samples t-test, and Chi-square test (or Fisher's exact test). Results:Among 502 fetuses, karyotyping plus CMA detected chromosomal abnormalities in 223 cases (44.4%, 223/502), including trisomy 18 (57.0%, 127/223) and trisomy 13 (23.3%, 52/223). CMA additionally identified nine pathogenic copy number variations (1.8%, 9/502) and five uniparental disomies (1.0%, 5/502), increasing the total diagnostic yield from 44.4% to 47.2%. The genetic abnormality rate was significantly lower in isolated (14.8%, 24/162) versus non-isolated omphalocele (64.7%, 220/340) ( χ2=109.34, P<0.001). WES detected variants in nine of 16 karyotype/CMA-negative cases, including five pathogenic variants involving PIK3CA and CDKN1C. Eight imprinting disorders (1.6%, 8/502) were identified, including five Beckwith-Wiedemann syndrome cases. Among 499 cases with follow-up, 401 (80.4%, 401/499) underwent pregnancy termination. Live birth rate was higher in isolated versus non-isolated groups [42.5% (69/162) vs. 8.5% (29/340), χ2=77.67, P<0.001]. Three cases were lost to follow-up. The one-year survival rate was 93.9% (92/98) in live-born infants. Conclusion:Aneuploidy (particularly trisomy 18) is the primary genetic etiology of omphalocele. CMA and WES significantly improve diagnostic yield. Isolated omphalocele has a more favorable prognosis, while non-isolated cases show significantly higher genetic abnormality rates. A stratified testing strategy is recommended: karyotyping plus CMA for isolated cases and prioritization of WES for multiple anomalies.
9.Study of genetic profiles and haematological phenotypes of δ-thalassemia in Guangdong population
Xiaojun CHEN ; Fan JIANG ; Jianying ZHOU ; Jian LI ; Xuewei TANG ; Guilan CHEN ; Fatao LI ; Fang TANG ; Ren ZHANG ; Dongzhi LI
Chinese Journal of Laboratory Medicine 2024;47(1):49-56
Objective:To investigate genetic variation profiles of δ-globin (HBD gene) and hematological phenotypes in Guangdong population.Methods:Retrospective case analysis was performed in this study. Blood samples of 11 616 couples who participated in free thalassemia screening in Guangzhou from July 2020 to December 2022 were collected which underwent blood routine tests and hemoglobin (Hb) capillary electrophoresis. According to the results, 154 samples were enrolled in this study: (1)group of 35 cases with HbA 2 <2.0% but no HbF band; (2)group of 64 cases with HbA 2 < 2.0% and HbF band; (3)group of 25 cases with HbA 2 <2.0% and suspected HbA 2 variants; (4) group of 25 cases with HbA 2 ≥2.0% and <3.5% and HbF band, as well as abnormal blood routine report [mean corpuscular volume (MCV) <82 fl and/or mean corpuscular hemoglobin (MCH) <27 pg]; (5)group of 5 cases with HbA 2 ≥2.0% and <3.0% accompanied with β thalassemia gene carriers Sanger sequencing was used to detect single nucleotide variants of δ-globin. Results:(1) A total of 22 genetic variations were detected, including 6 de novo variations, and the top 3 genetic variations were respectively c.-127T>C (57.02%, 65/114), c.-80T>C (9.65%, 11/114), c.349C>T (7.89%, 9/114). (2) In group of patients with HbA 2 <2.0% but no HbF band, 22 cases (62.85%, 22/35) had HBD gene variation, including 7 cases with MCV and MCH lower than reference values, 4 cases with α thalassemia; 13 cases had no HBD gene variation, including 12 cases with lower MCV and MCH. Among 19 cases with abnormal blood routine test results, levels of HbA 2 in patients (7 cases) with HBD gene variation were lower compared with those without HBD gene variation (12 cases) ( P<0.01%). (3)In group of patients with HbA 2<2.0% with HbF band, 59 cases (92.18%, 59/64) had HBD gene variations whose mutations all occurred in promoter region, and the HbF were all lower than 5.0%; 5 cases with HbF >5.0% had no HBD gene variation. (4) In group of patients with HbA 2 <2.0% and suspected HbA 2 variants, the detection rate was 100% (25/25) and δ-globin variants <1.0%. (5) In group of patients with HbA 2 ≥2.0% and <3.5% and HbF band accompanied with abnormal blood routine results, no HBD gene variation was found. (6) In group of 5 patients with HbA 2 ≥2.0% and <3.0% with β thalassemia gene carriers, HBD gene variation were found in all cases, and the level of HbA 2 was (2.62±0.17)% and HbF was (3.62±2.22)%. Conclusions:There are various genotypes of HBD gene variation, among which HBD: c.-127T>C is the most common in Guangdong population in China. Mutations in the promoter region may cause decrease in HbA 2 and increase in HbF which is mostly less than 5% but exceeds 5.0% when combined with β thalassemia. Our study enriched the gene mutation profiles of HBD gene in Guangdong population.
10.Molecular cytogenetic analysis and clinical outcomes of fetuses with congenital diaphragmatic hernia
Yanlin LI ; Min PAN ; Suting XU ; Ru LI ; Jin HAN ; Huizhu ZHONG ; Xiangyi JING ; Wei ZHONG ; Dongzhi LI
Chinese Journal of Perinatal Medicine 2024;27(12):993-1000
Objective:To investigate the correlation between clinical outcomes of congenital diaphragmatic hernia (CDH) and chromosomal abnormalities.Methods:This was a retrospective study involving 101 fetuses who underwent invasive prenatal diagnosis and chromosomal analysis for CDH at the Prenatal Diagnosis Center of Guangzhou Medical University Affiliated Women and Children's Medical Center from January 1, 2010, to December 31, 2021. According to ultrasound results, they were divided into the isolated CDH group and the complex CDH group. The results of chromosomal karyotype analysis or chromosomal microarray analysis (CMA) and birth outcomes were analyzed. For live-born children, follow-up results were analyzed. Statistical analysis was performed using t-test or Chi-square (or Fisher's exact) test. Results:(1) The mean age of the mothers of the 101 fetuses was (29.6±5.3) years, ranging from 20 to 47 years, and 16 mothers (15.8%) were over 35 years old. The mean gestational age at invasive prenatal diagnosis was (27.1±5.0) weeks, ranging from 13 weeks and 3 days to 38 weeks and 3 days; the mean gestational age at first diagnosis of CDH was (26.6±4.8) weeks, ranging from 13 weeks and 3 days to 38 weeks and 3 days. (2) The 101 fetuses were divided into isolated CDH group (81 cases, 80.2%) and complex CDH group (20 cases, 19.8%) based on whether they had other ultrasound abnormalities. Among the 20 complex cases, 13 had more than two types of malformations, with cardiovascular system malformations being the most common (11 cases, including seven chromosomal abnormalities). The highest proportion of chromosomal abnormalities was found in fetuses with central nervous system malformations (3/4). (3) Among the 101 CDH fetuses, 31 (30.7%) underwent chromosomal karyotype analysis alone, 39 (38.6%) underwent CMA alone, and 31 (30.7%) underwent both tests. The rate of chromosomal abnormalities was 13.9% (14/101). The detection rates of abnormalities by chromosomal karyotype analysis and CMA were 16.1% (10/62) and 14.3% (10/70), respectively. The additional detection rate by CMA was 2.8% (2/70). (4) The gestational age at diagnosis in the complex CDH group was earlier than that in the isolated CDH group [(22.7±4.2) weeks vs. (27.7±4.6) weeks, t=4.47, P<0.001]. The total detection rate, as well as the detection rates by chromosomal karyotype analysis and CMA, were higher in the complex CDH group than those in the isolated CDH group [45.0% (9/20) vs. 6.2% (5/81), χ2=17.13; 7/15 vs. 6.4% (3/47), χ2=10.82; 5/11 vs. 8.8% (5/57), χ2=7.55; all P<0.01]. (5) Among the 101 CDH fetuses, two were lost to follow-up, and 99 (98.0%) were successfully followed up. Among these 99 cases, 48 were terminated, and 51 were live births. The chromosomal abnormality rate in the 48 terminated fetuses was 25.0% (12/48), including 28 isolated cases and 20 complex cases. All 51 live births were isolated cases, with 45 (88.2%) cured by postnatal surgery and six (11.8%) having adverse clinical outcomes (including two preoperative deaths, three postoperative deaths, and one postoperative recurrence). Conclusions:The rate of chromosomal abnormalities in CDH is high, and it is higher in complex CDH than in isolated CDH. When prenatal diagnosis reveals fetal CDH, invasive prenatal diagnosis is recommended to exclude chromosomal karyotype abnormalities, with CMA recommended as the preferred chromosomal testing method.

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