1.Enlarged multicystic dysplastic kidneys with oligohydramnios during infancy caused by NPHP3 gene mutation.
Youwei BAO ; Xiaoli PAN ; Shuqing PAN ; Danyan ZHUANG ; Haibo LI ; Qitian MU ; Lulu YAN
Chinese Journal of Medical Genetics 2022;39(5):510-513
OBJECTIVE:
To explore the clinical features and genomic abnorm ality of a fetus enlarged multicystic dysplastic kidneys with oligohydramnios caused by NPHP3 gene mutation.
METHODS:
The fetuse was found to have multicystic dysplastic kidneys with oligohydramnios upon ultrasonography during the second trimester. Following induced abortion, fetal tissue was collected for the extraction of DNA, chromosomal microarray analysis (CMA) and whole exome sequencing (WES). Sanger sequencing was used to verify the suspected variants in the family.
RESULTS:
Antenatal ultrasound examination at 19 weeks showed "polycystic" kidneys with Oligohydramnios. Delivery was by induced labour because of the critically low amniotic fluid volume. Testing of CMA was normal. WES showed a compound heterozygous mutation of c.1817G>A, p.W606X; c.432dupA, p.E145Rfs*18 mutations are novel mutations in this study.
CONCLUSION
The research may further expand the NPHP3 gene mutation spectrum. Enlarged multicystic dysplastic kidneys with oligohydramnios caused by NPHP3 gene mutation at least include one or two splice site mutation, frameshift mutation or nonsense mutation foetal poor prognosis.
Amniotic Fluid
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Female
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Humans
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Kidney Diseases, Cystic
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Multicystic Dysplastic Kidney/genetics*
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Mutation
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Oligohydramnios/genetics*
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Polycystic Kidney Diseases
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Pregnancy
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Ultrasonography, Prenatal
2.Study on newborn screening for Duchenne muscular dystrophy and diagnostic strategy.
Youwei BAO ; Xiaoli PAN ; Jiewen PAN ; Shuqing PAN ; Danyan ZHUANG ; Haibo LI ; Zongfu CAO
Chinese Journal of Medical Genetics 2021;38(5):430-434
OBJECTIVE:
To establish a newborn screening system for Duchenne muscular dystrophy (DMD) through assessment of MM isoenzyme of creatine kinase (CK-MM) activity.
METHODS:
The CK-MM level was detected using dry blood spot filter paper from 10 252 male newborns. The results were grouped based on their gestational age, sampling time and intervals between the experiments. The threshold value for CK-MM necessitating genetic testing was determined. Next-generation sequencing (NGS) was carried out for those with a CK-MM value over the threshold, and the result was verified by multiplex ligation-dependent probe amplification (MLPA).
RESULTS:
Based on the result of non-parametric rank sum test, the median CK-MM concentration has increased with the gestational age, and was inversely correlated with the age of the newborns among unaffected specimens. CK-MM on dry blood spot filter paper can be stable for 14 days at 2-8℃. Statistical analysis of CK-MM value of the 10 252 neonates suggested that the threshold may be set as 700 ng/mL. Exonic deletions were found in 2 confirmed cases, whose CK-MM level was greater than 2000 ng/mL.
CONCLUSION
Detection of CK-MM in dry blood spot filter paper has provided an effective method for newborn screening of DMD. This simple and inexpensive method can be used for large-scale screening, which is of great value to the early intervention and treatment of the disease.
Dystrophin/genetics*
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Exons
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Humans
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Infant, Newborn
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Male
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Multiplex Polymerase Chain Reaction
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Muscular Dystrophy, Duchenne/genetics*
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Neonatal Screening
3.Analysis of TUBB2B gene variant in a fetus with complex cortical dysplasia with other brain malformations-7.
Lulu YAN ; Zhaier LU ; Yingwen LIU ; Chunxiao HAN ; Hongjun YING ; Youwei BAO ; Jiangyang XUE ; Haibo LI
Chinese Journal of Medical Genetics 2022;39(3):301-304
OBJECTIVE:
To explore the genetic basis for a fetus with dysgenesis of corpus callosum and other brain malformations.
METHODS:
Whole exome sequencing was carried out for the fetus and its parents. Suspected pathogenic variants were verified by Sanger sequencing.
RESULTS:
A novel de novo missense variant c.758T>A (p.L253Q) of the TUBB2B gene was identified, which was unreported previously. Based on the guidelines from the American College of Medical Genetics, the c.758T>A variant was predicted to be likely pathogenic. Bioinformatics analysis predicted that the leucine at position 253 was highly conserved among various species, and the c.758T>A variant may impact the formation of hydrogen bonds between Leu253 and Asp249 and Met257 residues, which in turn may affect the combination of GTP/GDP and function of the TUBB2B protein.
CONCLUSION
The c.758T>A variant of the TUBB2B gene probably underlay the fetal malformations in this Chinese family. Above discovery has enriched the spectrum of TUBB2B gene variants and provided a basis for genetic counseling and prenatal diagnosis.
Brain
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Female
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Fetus/abnormalities*
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Humans
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Malformations of Cortical Development/genetics*
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Pregnancy
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Prenatal Diagnosis
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Tubulin/genetics*
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Whole Exome Sequencing
4.Diagnosis a fetus with Coffin-Siris syndrome due to variant of SMARCA4 gene by whole exome sequencing.
Youwei BAO ; Xiaoli PAN ; Shuqing PAN ; Lisha GE ; Danyan ZHUANG ; Haibo LI
Chinese Journal of Medical Genetics 2022;39(12):1375-1378
OBJECTIVE:
To explore the clinical phenotype and genetic basis for a fetus suspected for Coffin-Siris syndrome.
METHODS:
Chromosomal microarray analysis (CMA) and whole exome sequencing (WES) were carried out for the fetus. Candidate variant was verified by Sanger sequencing.
RESULTS:
Prenatal ultrasound at 23rd gestational week has revealed fetal ventriculomegaly. No abnormality was found by CMA, while WES revealed that the fetus has harbored a de novo heterozygous c.2851G>A (p.G951R) variant of the SMARCA4 gene, which was predicted to be pathogenic.
CONCLUSION
Genetic testing should be considered for fetuses featuring progressive widening of lateral cerebral ventricles.
Female
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Humans
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Pregnancy
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DNA Helicases/genetics*
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Fetus
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Genetic Testing
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Nuclear Proteins/genetics*
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Phenotype
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Transcription Factors/genetics*
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Exome Sequencing
5.Screening and genotyping of thalassemia in Ningbo
Xiaoli PAN ; Shuqing PAN ; Youwei BAO ; Lingli PAN ; Haibo LI
Chinese Journal of Endemiology 2023;42(7):548-553
Objective:To study the genotyping of thalassemia in Ningbo population and provide a reference basis for future prevention and control of thalassemia in Ningbo.Methods:Patients with suspected thalassemia attending Ningbo Women and Children's Hospital from January 2019 to March 2022 were selected for the study, and DNA was extracted from dried blood spot specimens by collecting peripheral blood, and detection of thalassemia hotspot variants was performed by fluorescence PCR melting curve analysis combined with Sanger sequencing or multiplex ligation-dependent probe amplification (MLPA).Results:A total of 2 680 cases were included in the patients with suspected thalassemia, and 1 426 cases of thalassemia gene carriers were detected, with an overall detection rate of 53.2%. Among them, 595 cases (41.7%) were α-thalassemia, with -- SEA/αα, αα/-α 3.7 and -- SEA/-α 3.7 being more common; 807 cases (56.6%) were β-thalassemia, with β IVS-Ⅱ-654/β N, β CD41-42/β N and β CD17/β N being more common; 24 cases (1.7%) were αβ-combined thalassemia. Among them, six rare variant types were included, including fusion gene (Fusion), -- FIL, HBA2:c.376C>T, CD8/9(+G), IVS-Ⅰ-2(T>C) and IVS-Ⅱ-1(G>A), all of which were reported for the first time in Ningbo. Conclusion:Among suspected thalassemia patients in Ningbo, the detection rate of thalassemia is high, and the types of gene variants are complex, so the awareness of thalassemia gene testing for anemic patients should be raised.
6.Genetic testing of thalassemia in pregnant women in Ningbo City and analysis of changes of erythrocyte parameters in early pregnancy
Xiaoli PAN ; Shuqing PAN ; Youwei BAO ; Haibo LI
Chinese Journal of Endemiology 2023;42(9):716-721
Objective:To study the results of thalassemia gene detection and prenatal diagnosis in pregnant women in Ningbo City, and analyze the characteristics of erythrocyte parameters in early pregnancy.Methods:A total of 636 suspected thalassemia pregnant women treated in Ningbo Women and Children's Hospital from January 2019 to September 2021 were selected as the research subjects, the dry blood spots of pregnant women were collected for thalassemia gene detection; and the amniotic fluid of pregnant women with thalassemia gene carried by both husband and wife was extracted for prenatal diagnosis, and the results of thalassemia gene detection and prenatal diagnosis were analyzed. Meanwhile, in the medical record system of Ningbo Women and Children's Hospital, the detection results of erythrocyte parameters in early pregnancy of pregnant women with thalassemia gene (thalassemia group) and healthy pregnant women (control group) were investigated. Erythrocyte parameters including hemoglobin (Hb), red blood cell count (RBC), mean corpuscular hemoglobin concentration (MCHC), mean corpuscular hemoglobin content (MCH), mean corpuscular volume (MCV), hematocrit (HCT) and red blood cell distribution width (RDW) were compared between groups and among different thalassemia gene variants.Results:Among 636 suspected thalassemia pregnant woman, 254 cases (39.94%) were confirmed thalassemia gene carriers, including 114 cases of α-thalassemia, 132 cases of β-thalassemia, and 8 cases of αβ-compound thalassemia. After genetic counseling, 11 women finally received prenatal diagnosis, 7 fetuses (7/11) were found to carry thalassemia gene, including two cases of -- SEA/αα and β CD17/β N, respectively; one case of β CD26/β N, αα/-α 3.7 and β CD41-42/β CD41-42, respectively. The results of erythrocyte parameters detection showed that compared with the control group ( n = 80), there were statistically significant differences ( P < 0.05) in various erythrocyte parameters in α-thalassemia group ( n = 77) and β-thalassemia group ( n = 87); and there were significant differences ( P < 0.05) in Hb, HCT, MCV, MCH and MCHC among the four major genotypes (-- SEA/αα, β IVS-Ⅱ-654/β N, β CD17/β N and β CD41-42/β N). Conclusions:The genetic testing of thalassemia in pregnant women in Ningbo City is mainly α-thalassemia or β-thalassemia, and prenatal diagnosis is necessary for pregnant women carrying thalassemia gene. The erythrocyte parameters in early pregnancy of pregnant women carrying thalassemia gene are changed, and there are differences among different genotypes.
7.Genetic variation of thalassemia in children in Ningbo City and its correlation with erythrocyte parameters
Xiaoli PAN ; Shuqing PAN ; Youwei BAO ; Junming GUO
Chinese Journal of Endemiology 2022;41(8):644-648
Objective:To explore the type and composition of thalassemia gene variation in children in Ningbo City, and to analyze its correlation with erythrocyte parameters.Methods:From January 2019 to December 2020, 785 children who underwent thalassemia gene testing in Ningbo Women and Children's Hospital were selected as the retrospective research subjects to analyze the type and composition of thalassemia gene variation in local children. A total of 238 thalassemia gene mutation carriers and 100 healthy children (control group) who underwent physical examination during the same period were selected for routine blood test to analyze the correlation between thalassemia gene mutation types and serological indexes.Results:Among the 785 children who underwent thalassemia gene testing, 571 were confirmed as carriers of thalassemia gene mutation, with a detection rate of 72.7%, including 228 cases of α-thalassemia, 337 cases of β-thalassemia, and 6 cases of αβ-complex type thalassemia. It covered 17 variant types and 25 gene combinations. There were significant differences in red blood cell count (RBC), hematokrit (HCT), hemoglobin concentration (Hb), mean corpuscular hemoglobin (MCH), mean corpuscular hemoglobin concentration (MCHC), mean corpuscular volume (MCV) and red blood cell distribution width (RDW) between the control, α-thalassemia and β-thalassemia groups ( H/ F = 125.03, 86.24, 141.06, 192.99, 121.46, 198.63, 178.06, P < 0.001). And there were statistically significant differences in HCT, Hb, MCH, MCV and RDW among the four common genotypes (-- SEA/αα, β IVS-Ⅱ-654/β N, β CD41-42/β N and β CD17/β N) in this test ( F = 5.03, 3.34, 6.24, 10.33, 6.83, P < 0.05). Conclusion:The genotypes of children with thalassemia in Ningbo City are diverse, and the erythrocyte parameters are different among different genotypes.