scholarly journals Genetic Examination for Fetuses with Increased Fetal Nuchal Translucency by Genomic Technology

2020 ◽  
Vol 160 (2) ◽  
pp. 57-62
Author(s):  
Shuya Xue ◽  
Huanchen Yan ◽  
Jingsi Chen ◽  
Nan Li ◽  
Jiayan Wang ◽  
...  
Keyword(s):  
Exome Sequencing ◽  
Detection Rate ◽  
Nuchal Translucency ◽  
Compound Heterozygous Mutation ◽  
Heterozygous Mutation ◽  
Compound Heterozygous ◽  
Chromosomal Microarray Analysis ◽  
Chromosomal Anomalies ◽  
Crown Rump Length ◽  
Pathogenic Variants

This study aims to investigate the value of chromosomal microarray analysis (CMA) and whole exome sequencing (WES) in fetuses with increased nuchal translucency (defined as NT above the 95th centile for the crown-rump length). A total of 374 singleton pregnancies with gestational ages ranging from 11 to 13 + 6 weeks were investigated. Ultrasound displayed increased NT and no detectable structural malformations in these fetuses. Pregnancies were divided into 4 groups according to the NT values: 95th centile-3.4 mm (114 cases); 3.5-4.4 mm (150 cases); 4.5-5.4 mm (55 cases); and ≥5.5 mm (55 cases). The possible chromosomal anomalies were all analyzed by CMA first. Furthermore, 24 cases with increased NT but negative CMA results were investigated by WES, and the outcomes were followed up. Among all the 374 cases, causative genetic defects were detected in 100/374 (26.7%) of the cases along with 9 variants of unknown significance (VOUS) by CMA. CMA testing yielded 30 pathogenic variants (30/55), accounting for a detection rate of 54.5%, and 1 VOUS in the group of NT ≥5.5 mm, indicating the highest detection rate in the 4 groups. The 24 cases of the CMA negative sub-cohort with WES analysis further yielded 2 VOUS and 3 likely pathogenic variants, including 2 dominant de novo mutations in SOS1 and ECE1 and 1 recessive inherited compound heterozygous mutation in PIGN, which are associated with cardiac defects. All 3 cases opted for termination of pregnancy (TOP). In addition, 2 cases with increased NT were negative by both CMA and WES analysis, and fetal demise occurred. In conclusion, for the investigation of fetuses with increased NT exome sequencing is suggested to be considered in cases with negative CMA findings. However, appropriate genetic counseling should be given to optimizing its utilization in prenatal diagnosis.

scholarly journals Identification of Novel ADGRV1 and KCNC2 Variants Using Whole-Exome Sequencing in Two Colombian Patients with Usher and Encephalopathy Syndromes

2021 ◽  
Author(s):  
Estephania Candelo ◽  
Lorena Diaz-Ordoñez ◽  
Rafael Pacheco ◽  
Emelina Ruiz ◽  
Harry Pachajoa
Keyword(s):  
Exome Sequencing ◽  
Whole Exome Sequencing ◽  
Usher Syndrome ◽  
Epileptic Encephalopathy ◽  
Compound Heterozygous Mutation ◽  
Heterozygous Mutation ◽  
Epilepsy Syndrome ◽  
Compound Heterozygous ◽  
Whole Exome ◽  
Excellent Method

Abstract Introduction: Usher syndrome has a broad phenotypic and genotypic spectrum. Developmental and epileptic encephalopathy-52 (DEE52) is a sever autosomal recessive seizure disorder that is characterized by infantile onset of refractory seizures, consequently resulting in delayed global development. This study aimed to describe the clinical features and to investigate the four variants identified in a Colombian family with Usher syndrome and KCNC2 encephalopathy syndrome.Methods and Results: We present a case of a family with two clinically relevant phenotypes: a mother with a compound heterozygous mutation causing Usher Syndrome, type IIC (USH2C) and her 15-year-old son who carried one heterozygous variant in the KCNC2 gene (p.P470S) and two cis mutations (p.V2927I and p.Q4955EfsTer10) in the ADGRV1 gene segregated from his mother, and a second non-disrupted allele. Owing to this, the boy did not present with USH2C but presented a developmental epilepsy syndrome. His younger sibling was unaffected, although he did inherit the trans mutation in a single pathogenic allele from his mother.Discussion and Conclusion: Whole-exome sequencing helps detect genes related to known and novel hearing loss and seizure syndrome. However, familiar segregation studies are an excellent method to clarify genotype-phenotype correlation in families, where multiple genes of clinically relevant have been identified. This method helps determine the genotype-phenotype relationship of a disease, which is associated with the clinical presentation and determines the pathogenicity of variants that are classified as variants of uncertain clinical significance.

scholarly journals Case Report: Further Delineation of Neurological Symptoms in Young Children Caused by Compound Heterozygous Mutation in the PIEZO2 Gene

2021 ◽  
Vol 12 ◽  
Author(s):  
Magdalena Klaniewska ◽  
Maria Jedrzejowska ◽  
Malgorzata Rydzanicz ◽  
Justyna Paprocka ◽  
Mateusz Biela ◽  
...  
Keyword(s):  
Motor Development ◽  
Genetic Diagnosis ◽  
Hip Dislocation ◽  
Compound Heterozygous Mutation ◽  
Heterozygous Mutation ◽  
Compound Heterozygous ◽  
Loss Of Function ◽  
Pathogenic Variants ◽  
Cognitive Delay ◽  
Somatosensory Neurons

PIEZO2 protein is a unique ion channel that converts mechanical impulses into cellular signals in somatosensory neurons and is involved in various mechanotransduction pathways. The recessive PIEZO2 loss-of-function pathogenic variants are associated with distal arthrogryposis with impaired proprioception and touch (DAIPT). Here we present three new DAIPT patients. The genetic diagnosis was established by exome sequencing and let us to identify 6 novel loss-of-function PIEZO2 variants: four splicing (c.1080+1G>A, c.4092+1G>T, c.6355+1G>T, and c.7613+1G>A), one nonsense (c.6088C>T) and one frameshift variant (c.6175_6191del) for which mosaic variant was identified in proband's mother. All patients presented typical symptoms at birth, with congenital contractures, bilateral hip dislocation/dysplasia, generalized hypotonia, transient feeding and difficulties. Two were afflicted by transient respiratory insufficiency. In all children motor development was severely delayed. In one patient, severe cognitive delay was also observed. Moreover, among the cases described by us there is the youngest diagnosed child to date.

scholarly journals Simultaneous Identification of Both MFSD8 and RDH12 Pathogenic Variants in a Chinese Family Affected With Retinitis Pigmentosa

2021 ◽  
Vol 12 ◽  
Author(s):  
Yihui Wang ◽  
Yanling Teng ◽  
Desheng Liang ◽  
Zhuo Li ◽  
Lingqian Wu
Keyword(s):  
Retinitis Pigmentosa ◽  
Molecular Genetic ◽  
Cerebellar Atrophy ◽  
Compound Heterozygous Mutation ◽  
Chinese Family ◽  
Heterozygous Mutation ◽  
Compound Heterozygous ◽  
Homozygous Mutation ◽  
Pathogenic Variants ◽  
Reproductive Counseling

Retinitis pigmentosa (RP) is characterized by tremendous genetic and phenotypic heterogeneity. Here, we investigate the pathogeny of RP in a family to provide evidence for genetic and reproductive counseling for families. Although this pregnant woman of 8+3 weeks presented with RP, her first baby was born with RP, epilepsy, and cerebellar atrophy. The research identified a compound heterozygous mutation (c.998+3_998+6del/deletion) in the MFSD8 gene of the first born, explaining the cause of the proband’s disease, which cannot explain the mother’s. Then, a homozygous mutation c.343+1G > A in RDH12 of the mother was found. RT-PCR is employed to find that there is a skipping of exon 10 in MFSD8 and a 15-nucleotide retention of intron5 in RDH12. The coexistence of two independent instances of RP caused by distinct genes in one pedigree is demonstrated. Based on the diagnosis, a prenatal diagnosis performed on the fetus found that the fetus’s MFSD8 is affected by the same mutation as the proband. The research underscoring the complexity of RP and the need for the combination of extensive molecular genetic testing and clinical characterization in addition expands the spectrum of MFSD8 mutations. Finally, it is expected that the family members would be prevented from reproducing children with the similar disease.

scholarly journals Whole-Exome Sequencing Identified a Novel Compound Heterozygous Mutation of LRRC6 in a Chinese Primary Ciliary Dyskinesia Patient

2018 ◽  
Vol 2018 ◽  
pp. 1-5 ◽  
Author(s):  
Lv Liu ◽  
Hong Luo
Keyword(s):  
Exome Sequencing ◽  
Whole Exome Sequencing ◽  
Primary Ciliary Dyskinesia ◽  
Premature Stop Codon ◽  
Compound Heterozygous Mutation ◽  
Heterozygous Mutation ◽  
Compound Heterozygous ◽  
Mrna Levels ◽  
Whole Exome ◽  
Ciliary Dyskinesia

Primary ciliary dyskinesia (PCD) is a clinical rare peculiar disorder, mainly featured by respiratory infection, tympanitis, nasosinusitis, and male infertility. Previous study demonstrated it is an autosomal recessive disease and by 2017 almost 40 pathologic genes have been identified. Among them are the leucine-rich repeat- (LRR-) containing 6 (LRRC6) codes for a 463-amino-acid cytoplasmic protein, expressed distinctively in motile cilia cells, including the testis cells and the respiratory epithelial cells. In this study, we applied whole-exome sequencing combined with PCD-known genes filtering to explore the genetic lesion of a PCD patient. A novel compound heterozygous mutation in LRRC6 (c.183T>G/p.N61K; c.179-1G>A) was identified and coseparated in this family. The missense mutation (c.183T>G/p.N61K) may lead to a substitution of asparagine by lysine at position 61 in exon 3 of LRRC6. The splice site mutation (c.179-1G>A) may cause a premature stop codon in exon 4 and decrease the mRNA levels of LRRC6. Both mutations were not present in our 200 local controls, dbSNP, and 1000 genomes. Three bioinformatics programs also predicted that both mutations are deleterious. Our study not only further supported the importance of LRRC6 in PCD, but also expanded the spectrum of LRRC6 mutations and will contribute to the genetic diagnosis and counseling of PCD patients.

scholarly journals Rapid Trio Exome Sequencing for Autosomal Recessive Renal Tubular Dysgenesis in Recurrent Oligohydramnios

2021 ◽  
Vol 12 ◽  
Author(s):  
Shin-Yu Lin ◽  
Gwo-Tsann Chuang ◽  
Chien-Hui Hung ◽  
Wei-Chou Lin ◽  
Yung-Ming Jeng ◽  
...  
Keyword(s):  
Exome Sequencing ◽  
Neonatal Death ◽  
Autosomal Recessive ◽  
Compound Heterozygous Mutation ◽  
Heterozygous Mutation ◽  
Compound Heterozygous ◽  
Early Neonatal Death ◽  
Renal Tubular Dysgenesis ◽  
Whole Exome ◽  
Renal Tubular

Oligohydramnios is not a rare prenatal finding. However, recurrent oligohydramnios is uncommon, and genetic etiology should be taken into consideration. We present two families with recurrent fetal oligohydramnios that did not respond to amnioinfusion. Rapid trio-whole-exome sequencing (WES) revealed mutations in the AGT gene in both families within 1 week. The first family had a compound heterozygous mutation with c.856 + 1G > T and c.857-619_1269 + 243delinsTTGCCTTGC changes. The second family had homozygous c.857-619_1269 + 243delinsTTGCCTTGC mutations. AGT gene mutation may lead to autosomal recessive renal tubular dysgenesis, a rare and lethal disorder that can result in early neonatal death. Both the alleles identified are known alleles associated with pathogenicity. Our findings suggest that trio-WES analysis may help rapidly identify causative etiologies that can inform prompt counseling and decision-making prenatally.

scholarly journals A Compound Heterozygous Mutation in the Ciliary Gene TTC21B Causes Nephronophthisis Type 12

2019 ◽  
Vol 09 (03) ◽  
pp. 198-202
Author(s):  
Wafaa Moustafa M. Abo El Fotoh ◽  
Amira Fathy Al-fiky
Keyword(s):  
Autosomal Recessive ◽  
Autosomal Recessive Inheritance ◽  
Compound Heterozygous Mutation ◽  
Heterozygous Mutation ◽  
Compound Heterozygous ◽  
Renal Disorder ◽  
Pathogenic Variants ◽  
Tubulointerstitial Lesions ◽  
Stage Renal Disease ◽  
End Stage

AbstractNephronophthisis (NPHP) is one of the renal ciliopathies and is also a cystic renal disorder with an autosomal recessive inheritance, which usually progresses to end-stage renal disease (ESRD). It affects children, adolescents, and young adults. In approximately 15% of cases, the features of a ciliopathy syndrome, which include liver fibrosis, skeletal anomalies, retinal abnormalities, and neurodevelopmental delay, will be present. We describe a case of a 2-year-old male child with ESRD on hemodialysis and a family record of a similar condition (his brother). The clinical features of this child are succinctly summarized. The genetic study was conducted using whole exome sequencing. TTC21B mutational variants were detected in our patient who exhibited nephrotic-range proteinuria, focal segmental glomerulosclerosis, and tubulointerstitial lesions that evolved to ESRD. Compound heterozygous mutations, c.626c > t (p.P209L) in exon 6 and c.450 g > a (p.W150Ter) in exon 5, were uncovered. These findings are in line with the description of autosomal recessive NPHP type 12. Both clinical and pathological diagnoses of NPHP are critical, bearing in mind ESRD as well as its related extrarenal defining features. Identification of the pathogenic variants in the TTC21B gene assisted in the successful proof of the clinical diagnosis NPHP12 as well as providing information for formal suitable prenatal counseling.

Congenital cataract with LSS gene mutations: a new case report

2017 ◽  
Vol 30 (11) ◽  
Author(s):  
Xiaodan Chen ◽  
Li Liu
Keyword(s):  
Case Report ◽  
Exome Sequencing ◽  
Pediatric Patient ◽  
Congenital Cataract ◽  
Gene Mutations ◽  
Compound Heterozygous Mutation ◽  
Heterozygous Mutation ◽  
Compound Heterozygous ◽  
Case Presentation ◽  
Whole Exome

AbstractBackground:Congenital cataract is one of the major causes of blindness and amblyopia in children. About one-third of the cases are inherited.Case presentation:We applied whole exome sequencing for a pediatric patient with congenital cataract, small penis, baldness and absence of eyebrows and detected a compound heterozygous mutation in the lanosterol synthase (Conclusions:We concluded that the mutations affect the structural stability of the protein to some extent.

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