scholarly journals The genotype analysis and prenatal genetic diagnosis among 244 pedigrees with methylmalonic aciduria in China

Author(s):  
Shuang Hu ◽  
Lina Liu ◽  
Zhihui Jiao ◽  
Xiangdong Kong

Abstract To investigate the phenotypes, biochemical features and genotypes for 244 pedigrees with methylmalonic aciduria (MMA) in China, and to perform the prenatal genetic diagnosis by chorionic villus for these pedigrees. Gene analyses were performed for 244 pedigrees. There are 130 families, chorionic villus sampling was performed on the pregnant women to conduct the prenatal diagnosis. Among 244 patients, 168 (68.9%) cases were combined methylmalonic aciduria and homocystinuria, 76 (31.1%) cases were isolated methymalonic aciduria. All the patients were diagnosed with MMA by their clinical manifestation, elevated blood propionylcarnitine, propionylcarnitine to acetylcarnitine ratio, and/or urine/blood methylmalonic acid with or without hyperhomocysteinemia. MMACHC, MUT, SUCLG1 and LMBRD1 gene variants were found in 236 (96.7%) pedigrees included 6 probands with only one heterozygous variant out of 244 cases. For the 130 pedigrees who received a prenatal diagnosis, 22 foetuses were normal, 69 foetuses were carriers of heterozygous variants, and the remaining 39 foetuses harboured compound heterozygous variants or homozygous variants. The follow-up results were consistent with the prenatal diagnosis. The present study indicates genetic heterogeneity in MMA patients. Genetic analysis is a convenient method for prenatal diagnosis that will aid in avoiding the delivery of MMA patients.

2020 ◽  
Author(s):  
YingJie Sun ◽  
Xiangdong Kong ◽  
Xuechao Zhao ◽  
Zhenhua Zhao

Abstract Background Spinal muscular atrophy (SMA) is a common and lethal autosomal recessive neurodegenerative disease, which is caused by mutations of the survival motor neuron 1 (SMN1) gene. At present, the gene therapy medicine for SMA, i.e. , Spinraza (Nusinersen), has been approved by the FDA, bringing hope to SMA patients and families. In this study, we analyzed the deletion of SMN gene in patients suspected of SMA, and performed prenatal genetic diagnosis of SMA. Methods In this study, we collected the peripheral blood of 419 probands and their parents who were treated in the genetic counseling clinic at our hospital from January 2010 to September 2019, and extracted DNA from the blood samples for analysis. Patients who were diagnosed with SMA were first tested by MLPA. The patients with negative MLPA results were further analysed with long-range PCR combined with nest PCR and validated by Sanger sequencing to look for point mutations. In 293 families, pregnant women were subjected to chorionic villus or amniotic fluid sampling for prenatal genetic diagnosis depending on gestational weeks. In addition to the above methods used for genetic diagnosis, we also used QF-PCR in all prenatal diagnoses, which can help detect the presence of trisomy of chromosome while eliminating maternal contamination. Results 1. Homozygous deletion of SMN1 exon 7 was detected in 96.40% (404/419) of patients. Homozygous deletion of SMN1 exon 7 alone was detected in 15 patients (3.60%). 2. In total, 10 point mutations were detected in the 15 pedigrees. Five of these variants have not been previously reported in the literature. 3. Among the 293 pedigrees that underwent one prenatal diagnosis, 118 foetuses were normal, 149 foetuses were carriers of heterozygous variants, and the remaining 72 foetuses harboured compound heterozygous variants or homozygous variants. 4. In all prenatal diagnoses, we found one 21-trisomy fetus by QF-PCR. Couples whose foetuses were normal or carriers continued the pregnancy, whereas couples whose foetuses harboured compound heterozygous variants or homozygous variants decided to terminate the pregnancy. The follow-up results were consistent with the prenatal diagnosis.


2020 ◽  
Vol 182 (10) ◽  
pp. 2417-2425
Author(s):  
Joanna Walczak‐Sztulpa ◽  
Anna Wawrocka ◽  
Beata Leszczynska ◽  
Boyana Mikulska ◽  
Heleen H. Arts ◽  
...  

2014 ◽  
Vol 3 (3) ◽  
pp. 838-848 ◽  
Author(s):  
Paula Jorge ◽  
Maria Mota-Freitas ◽  
Rosário Santos ◽  
Maria Silva ◽  
Gabriela Soares ◽  
...  

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Cong Zhou ◽  
Yuanyuan Xiao ◽  
Hanbing Xie ◽  
Shanling Liu ◽  
Jing Wang

Abstract Background Usher syndrome (USH) is the most common cause of inherited deaf-blindness. The current study aimed to identify pathogenic variants in a Chinese patient with hearing loss and to report the identification of a novel p.(Phe1583Leufs*10) variant in USH2A, which met the needs of prenatal diagnosis of the patient's mother. Case presentation Genomic DNA obtained from a five-year-old girl with hearing loss was analyzed via the hearing loss-targeted gene panels. We identified the compound heterozygous variants c.8559-2A>G and c.4749delT in Usher syndrome type 2A (USH2A) gene as the underlying cause of the patient; the former variation has been reported in the literature, but not the latter. The parents of the girl were heterozygous carriers. The two variants were classified as pathogenic. Based on these findings, amniotic fluid samples were used for prenatal diagnosis of the couple's fetus, which was found to carry c.4749delT but not c.8559-2A>G variation. During the follow-up period of more than 9 months after the birth of the fetus, it was confirmed that the infant was healthy. Conclusions The results of the present study identified two compound heterozygous USH2A variants in a patient with hearing loss and reported a novel USH2A variant which expands the spectrum of USH2A variants in USH.


2021 ◽  
Vol 12 ◽  
Author(s):  
Lingrong Kong ◽  
Shaojun Li ◽  
Zhenhua Zhao ◽  
Jun Feng ◽  
Guangquan Chen ◽  
...  

Noninvasive prenatal diagnosis (NIPD) of single-gene disorders has recently become the focus of clinical laboratories. However, reports on the clinical application of NIPD of Duchenne muscular dystrophy (DMD) are limited. This study aimed to evaluate the detection performance of haplotype-based NIPD of DMD in a real clinical environment. Twenty-one DMD families at 7–12 weeks of gestation were prospectively recruited. DNA libraries of cell-free DNA from the pregnant and genomic DNA from family members were captured using a custom assay for the enrichment of DMD gene exons and spanning single-nucleotide polymorphisms, followed by next-generation sequencing. Parental haplotype phasing was based on family linkage analysis, and fetal genotyping was inferred using the Bayes factor through target maternal plasma sequencing. Finally, the entire experimental process was promoted in the local clinical laboratory. We recruited 13 complete families, 6 families without paternal samples, and 2 families without probands in which daughter samples were collected. Two different maternal haplotypes were constructed based on family members in all 21 pedigrees at as early as 7 gestational weeks. Among the included families, the fetal genotypes of 20 families were identified at the first blood collection, and a second blood collection was performed for another family due to low fetal concentration. The NIPD result of each family was reported within 1 week. The fetal fraction in maternal cfDNA ranged from 1.87 to 11.68%. In addition, recombination events were assessed in two fetuses. All NIPD results were concordant with the findings of invasive prenatal diagnosis (chorionic villus sampling or amniocentesis). Exon capture and haplotype-based NIPD of DMD are regularly used for DMD genetic diagnosis, carrier screening, and noninvasive prenatal diagnosis in the clinic. Our method, haplotype-based early screening for DMD fetal genotyping via cfDNA sequencing, has high feasibility and accuracy, a short turnaround time, and is inexpensive in a real clinical environment.


2017 ◽  
pp. 109-115
Author(s):  
N.P. Veropotvelyan ◽  

The study presents data of different authors, as well as its own data on the frequency of multiple trisomies among the early reproductive losses in the I trimester of pregnancy and live fetuses in pregnant women at high risk of chromosomal abnormalities (CA) in I and II trimesters of gestation. The objective: determining the frequency of occurrence of double (DT) and multiple trisomies (MT) among the early reproductive losses in the I trimester of pregnancy and live fetuses in pregnant women at high risk of occurrence of HA in I and II trimesters of gestation; establishment of the most common combinations of diesel fuel and the timing of their deaths compared with single regular trisomy; comparative assessment materinskogo age with single, double and multiple trisomies. Patients and methods. During the period from 1997 to 2016, the first (primary) group of products in 1808 the concept of missed abortion (ST) of I trimester was formed from women who live in Dnepropetrovsk, Zaporozhye, Kirovograd, Cherkasy, Kherson, Mykolaiv regions. The average term of the ST was 8±3 weeks. The average age of women was 29±2 years. The second group (control) consisted of 1572 sample product concepts received during medical abortion in women (mostly residents of Krivoy Rog) in the period of 5-11 weeks of pregnancy, the average age was 32 years. The third group was made prenatally karyotyped fruits (n = 9689) pregnant women with high risk of HA of the above regions of Ukraine, directed the Centre to invasive prenatal diagnosis for individual indications: maternal age, changes in the fetus by ultrasound (characteristic malformations and echo markers HA) and high risk of HA on the results of the combined prenatal screening I and II trimesters. From 11 th to 14 th week of pregnancy, chorionic villus sampling was performed (n=1329), with the 16th week – platsentotsentez (n=2240), 18 th and 24 th week – amniocentesis (n=6120). Results. A comparative evaluation of maternal age and the prevalence anembriony among multiple trisomies. Analyzed 13,069 karyotyped embryonic and fetal I-II trimester of which have found 40 cases of multiple trisomies – 31 cases in the group in 1808 missed abortion (2.84% of total HA), 3 cases including 1 572 induced medabortov and 7 cases during 9689 prenatal research (0.51% of HA). Determined to share the double trisomies preembrionalny, fetal, early, middle and late periods of fetal development. Conclusion. There were no significant differences either in terms of destruction of single and multiple trisomies or in maternal age or in fractions anembrionalnyh pregnancies in these groups. Key words: multiple trisomies, double trisomy, missed abortion, prenatal diagnosis.


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