1.Genetic analysis of a Chinese pedigree with 18q21.2-q22.3 duplication and deletion in two offspring respectively resulting from a maternal intrachromosomal insertion.
Jiahong ZHOU ; Pan ZHOU ; Zhiyu LYU ; Hui ZHANG ; Qing LUO ; Lan YUAN ; Yang CHENG ; Xia WEN ; Jinbo LIU
Chinese Journal of Medical Genetics 2023;40(4):483-489
OBJECTIVE:
To provide prenatal diagnosis, pedigree analysis and genetic counseling for a pregnant woman who had given birth to a child featuring global developmental delay.
METHODS:
A pregnant woman who underwent prenatal diagnosis at the Affiliated Hospital of Southwest Medical University in August 2021 was selected as the study subject. Peripheral blood samples were collected from the woman, her husband and child, in addition with amniotic fluid sample during mid-pregnancy. Genetic variants were detected by G-banded karyotyping analysis and copy number variation sequencing (CNV-seq). Pathogenicity of the variant was predicted based on the guidelines from the American College of Medical Genetics and Genomics (ACMG). Candidate variant was traced in the pedigree to assess the recurrence risk.
RESULTS:
The karyotypes of the pregnant woman, her fetus, and affected child were 46,XX,ins(18)(p11.2q21q22), 46,X?,rec(18)dup(18)(q21q22)ins(18)(p11.2q21q22)mat and 46,XY,rec(18)del(18)(q21q22)ins(18)(p11.2q21q22)mat, respectively. Her husband was found to have a normal karyotype. CNV-seq has revealed a 19.73 Mb duplication at 18q21.2-q22.3 in the fetus and a 19.77 Mb deletion at 18q21.2-q22.3 in her child. The duplication and deletion fragments were identical to the insertional fragment in the pregnant woman. Based on the ACMG guidelines, the duplication and deletion fragments were both predicted to be pathogenic.
CONCLUSION
The intrachromosomal insertion of 18q21.2-q22.3 carried by the pregnant woman had probably given rise to the 18q21.2-q22.3 duplication and deletion in the two offspring. Above finding has provided a basis for genetic counseling for this pedigree.
Child
;
Female
;
Humans
;
Pregnancy
;
DNA Copy Number Variations
;
East Asian People
;
Pedigree
;
Prenatal Diagnosis/methods*
;
Chromosomes, Human, Pair 18/genetics*
;
Male
;
Fetus
;
INDEL Mutation
2.Optical genome mapping analysis of a Chinese pedigree with a rare chromosome 17 paracentric inversion insertion.
Hao WANG ; Yang YANG ; Nannan YANG ; Yan WANG ; Huawei LI ; Wensheng HU
Chinese Journal of Medical Genetics 2023;40(6):727-732
OBJECTIVE:
To carry out optical genome mapping (OGM) for a Chinese pedigree with a rare paracentric reverse insertion of chromosome 17.
METHODS:
A high-risk pregnant woman identified at the Prenatal Diagnosis Center of Hangzhou Women's Hospital in October 2021 and her family members were selected as the study subjects. Chromosome G banding analysis, fluorescence in situ hybridization (FISH), single nucleotide polymorphism array (SNP array) and OGM were applied to verify the balanced structural abnormality of chromosome 17 in the pedigree.
RESULTS:
Chromosomal karyotyping analysis and SNP array assay have identified a duplication of 17q23q25 in the fetus. Karyotyping analysis of the pregnant woman showed that the structure of chromosome 17 was abnormal, whilst SNP array has detected no abnormality. OGM revealed that the woman has carried a paracentric reverse insertion, which was confirmed by FISH. The karyotype of her husband was normal.
CONCLUSION
The duplication of 17q23q25 in the fetus has derived from a paracentric reverse insertion of chromosome 17 in its mother. OGM has the advantage for delineating balanced chromosome structural abnormalities.
Pregnancy
;
Humans
;
Female
;
Pedigree
;
In Situ Hybridization, Fluorescence
;
Chromosomes, Human, Pair 17/genetics*
;
East Asian People
;
Chromosome Aberrations
;
Prenatal Diagnosis
;
Chromosome Mapping
;
Chromosome Inversion
3.Prenatal diagnosis and genetic analysis of a fetus with partial deletion of Yq and mosaicism of 45,X.
Lijuan WANG ; Hui GUO ; Qi LIN ; Zhiyang HU ; Huiyan HE ; Mei YE ; Zhuojian LIANG ; Wenlong HU ; Hui GAO ; Di MA ; Yaqin SONG
Chinese Journal of Medical Genetics 2023;40(6):744-749
OBJECTIVE:
To carry out prenatal diagnosis and genetic analysis for a fetus with disorders of sex development (DSDs).
METHODS:
A fetus with DSDs who was identified at the Shenzhen People's Hospital in September 2021 was selected as the study subject. Combined molecular genetic techniques including quantitative fluorescence PCR (QF-PCR), multiplex ligation-dependent probe amplification (MLPA), chromosomal microarray analysis (CMA), quantitative real-time PCR (qPCR), as well as cytogenetic techniques such as karyotyping analysis and fluorescence in situ hybridization (FISH) were applied. Ultrasonography was used to observe the phenotype of sex development.
RESULTS:
Molecular genetic testing suggested that the fetus had mosaicism of Yq11.222qter deletion and X monosomy. Combined with the result of cytogenetic testing, its karyotype was determined as mos 45,X[34]/46,X,del(Y)(q11.222)[61]/47,X,del(Y)(q11.222),del(Y)(q11.222)[5]. Ultrasound examination suggested hypospadia, which was confirmed after elective abortion. Combined the results of genetic testing and phenotypic analysis, the fetus was ultimately diagnosed with DSDs.
CONCLUSION
This study has applied a variety of genetic techniques and ultrasonography to diagnose a fetus with DSDs with a complex karyotype.
Prenatal Diagnosis
;
Mosaicism
;
Chromosomes, Human, X
;
Chromosomes, Human, Y
;
Humans
;
Male
4.Clinical features and genetic analysis of two children with Williams-Beuren syndrome.
Mingzhu HUANG ; Lingling XU ; Xiaoyuan CHEN ; Linghua DONG ; Liyan MA ; Jinhai MA
Chinese Journal of Medical Genetics 2023;40(7):828-832
OBJECTIVE:
To explore the clinical and genetic characteristics of two children with Williams-Beuren syndrome (WBS).
METHODS:
Two children who had presented at the Department of Pediatrics, General Hospital of Ningxia Medical University respectively on January 26 and March 18, 2021 were selected as the study subjects. Clinical data and results of genetic testing of the two patients were analyzed.
RESULTS:
Both children had featured developmental delay, characteristic facies and cardiovascular malformation. Child 1 also had subclinical hypothyroidism, whilst child 2 had occurrence of epilepsy. Genetic testing revealed that child 1 has harbored a 1.54 Mb deletion in the 7q11.23 region, whilst child 2 has a 1.53 Mb deletion in the same region, in addition with a c.158G>A variant of the ATP1A1 gene and a c.12181A>G variant of the KMT2C gene. Based on the guidelines from the American College of Medical Genetics and Genomics, the c.158G>A and c.12181A>G variants were rated as variants of unknown significance (PM1+PM2_Supporting+PP2+PP3;PM2_Supporting).
CONCLUSION
Both children had characteristic features of WBS, for which deletions of the 7q11.23 region may be accountable. For children manifesting developmental delay, facial dysmorphism and cardiovascular malformations, the diagnosis of WBS should be suspected, and genetic testing should be recommended to confirm the diagnosis.
Child
;
Humans
;
Williams Syndrome/diagnosis*
;
Genetic Testing
;
Facies
;
Epilepsy/genetics*
;
Chromosomes, Human, Pair 7/genetics*
;
Chromosome Deletion
5.Genetic analysis of two children with developmental delay and intellectual disability.
Fengyang WANG ; Na QI ; Yue GAO ; Dong WU ; Mengting ZHANG ; Qian ZHANG ; Ke YANG ; Huijuan PENG ; Xingxing LEI ; Shixiu LIAO
Chinese Journal of Medical Genetics 2023;40(7):876-880
OBJECTIVE:
To explore the genetic etiology of two patients with developmental delay and intellectual disability.
METHODS:
Two children who were respectively admitted to Henan Provincial People's Hospital on August 29, 2021 and August 5, 2019 were selected as the study subjects. Clinical data were collected, and array comparative genomic hybridization (aCGH) was carried out on the children and their parents for the detection of chromosomal microduplication/microdeletions.
RESULTS:
Patient 1 was a 2-year-and-10-month female and patient 2 was a 3-year-old female. Both children had featured developmental delay, intellectual disability, and abnormal findings on cranial MRI. aCGH revealed that patient 1 has harbored arr[hg19] 6q14.2q15(84621837_90815662)×1, a 6.19 Mb deletion at 6q14.2q15, which encompassed ZNF292, the pathogenic gene for Autosomal dominant intellectual developmental disorder 64. Patient 2 has harbored arr[hg19] 22q13.31q13.33(46294326_51178264)×1, a 4.88 Mb deletion at 22q13.31q13.33 encompassing the SHANK3 gene, haploinsufficiency of which can lead to Phelan-McDermid syndrome. Both deletions were classified as pathogenic CNVs based on the guidelines of American College of Medical Genetics and Genomics (ACMG) and were not found in their parents.
CONCLUSION
The 6q14.2q15 deletion and 22q13-31q13.33 deletion probably underlay the developmental delay and intellectual disability in the two children, respectively. Haploinsufficiency of the ZNF292 gene may account for the key clinical features of the 6q14.2q15 deletion.
Humans
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Child
;
Female
;
Child, Preschool
;
Intellectual Disability/genetics*
;
Comparative Genomic Hybridization
;
Chromosome Disorders/genetics*
;
Chromosome Deletion
;
Magnetic Resonance Imaging
;
Chromosomes, Human, Pair 22
;
Developmental Disabilities/genetics*
;
Carrier Proteins/genetics*
;
Nerve Tissue Proteins/genetics*
6.Application of Familial Y-STR Haplotype Mismatch Tolerance in Genealogy Inference.
Meng-Jie TONG ; Ke ZHANG ; Cai-Xia LI ; Guang-Feng ZHANG ; Wen-Jie ZHANG ; Lan YANG ; Qing-Tang HOU ; Jing LIU
Journal of Forensic Medicine 2023;39(3):296-304
OBJECTIVES:
To provide a guideline for genealogy inference and family lineage investigation through a study of the mismatch tolerance distribution of Y-STR loci in Chinese Han male lineage.
METHODS:
Three Han lineages with clear genetic relationships were selected. YFiler Platinum PCR amplification Kit was used to obtain the typing data of 35 Y-STR loci in male samples. The variation of Y-STR haplotypes in generation inheritance and the mismatch tolerance at 1-7 kinship levels were statistically analyzed.
RESULTS:
Mutations in Y-STR were family-specific with different mutation loci and numbers of mutation in different lineages. Among all the mutations, 66.03% were observed on rapidly and fast mutating loci. At 1-7 kinship levels, the number of mismatch tolerance ranged from 0 to 5 on all 35 Y-STR loci, with a maximum step size of 6. On medium and slow mutant loci, the number of mismatch tolerance ranged from 0 to 2, with a maximum step size of 3; on rapidly and fast mutant loci, the number of mismatch tolerance ranged from 0 to 3, with a maximum step size of 6.
CONCLUSIONS
Combined use of SNP genealogy inference and Y-STR lineage investigation, both 0 and multiple mismatch tolerance need to be considered. Family lineage with 0-3 mismatch tolerance on all 35 Y-STR loci and 0-1 mismatch tolerance on medium and slow loci can be prioritized for screening. When the number of mismatch tolerance is eligible, family lineages with long steps should be carefully excluded. Meanwhile, adding fast mutant loci should also be handled with caution.
Male
;
Humans
;
Haplotypes
;
Chromosomes, Human, Y/genetics*
;
Microsatellite Repeats
;
Mutation
;
Asian People/genetics*
;
China
;
Genetics, Population
7.Progress on genome-wide association studies on mosaic chromosomal alterations.
Yu Xuan ZHAO ; Ming Yu SONG ; Can Qing YU ; Jun LYU ; Li Ming LI ; Dian Jian yi SUN
Chinese Journal of Epidemiology 2023;44(7):1146-1150
Mosaic chromosomal alteration (mCA) is referred to as large-scale somatic mutations on chromosomes, which results in diverse karyotypes in body. The mCA is regarded as one of the phenotypes of aging. Studies have revealed its associations with many chronic diseases such as hematopoietic cancers and cardiovascular diseases, but its genetic basis (e.g. genetic susceptibility variants) is still under-investigated. This paper reviews GWAS studies for mCA on autosomal chromosomes and sex chromosomes [mosaic loss of the Y chromosome (mLOY) and mosaic loss of the X chromosome (mLOX)] based on large population, respectively. Most of the genetic susceptibility loci found in studies for autosomal mCA were associated with copy-neutral loss of heterozygosity. The study of sex chromosome mCA focused on mosaic loss mutations. The number of genetic susceptibility loci for mLOY was high (up to 156), but it was relatively less for mLOX.
Humans
;
Male
;
Genome-Wide Association Study/methods*
;
Mosaicism
;
Genetic Predisposition to Disease
;
Chromosomes, Human, Y
;
Mutation
8.Clinical and genetic characteristic in patients with disorders of sex development caused by Y chromosome copy number variant.
Jun Ke XIA ; Feng Yan TIAN ; Ya Qin HOU ; Yong Jiang ZHAO ; Xiang Dong KONG
Chinese Journal of Pediatrics 2023;61(5):459-463
Objective: To investigate the clinical phenotype and genetic characteristics of disorders of sex development (DSD) caused by Y chromosome copy number variant (CNV). Methods: A retrospective analysis was performed on 3 patients diagnosed with DSD caused by Y chromosome CNV admitted to the First Affiliated Hospital of Zhengzhou University from January, 2018 to September, 2022. Clinical data were collected. Clinical study and genetic test were performed by karyotyping, whole exome sequencing (WES), low coverage whole genome copy number variant sequencing (CNV-seq), fluorescence in situ hybridization (FISH) and gonadal biopsy. Results: The 3 children, aged 12, 9, 9 years, the social gender were all female, presented with short stature, gonadal dysplasia and normal female external genital. No other phenotypic abnormality was found except for case 1 with scoliosis. The karyotype of all cases were identified as 46, XY. No pathogenic vraiants were found by WES. CNV-seq determined that case 1 was 47, XYY,+Y(2.12) and case 2 was 46, XY,+Y(1.6). FISH concluded that the long arm of Y chromosome was broken and recombined near Yq11.2, and then produced a pseudodicentric chromosome idic(Y). The karyotype was reinterpreted as mos 47, X, idic(Y)(q11.23)×2(10)/46, X, idic(Y)(q11.23)(50) in case 1. The karyotype was redefined as 45, XO(6)/46, X, idic(Y)(q11.22)(23)/46, X, del(Y)(q11.22)(1) in case 2. 46, XY, -Y(mos) was found by CNV-seq in case 3, and the karyotype of 45, XO/46, XY was speculated. Conclusions: The clinical manifestations of children with DSD caused by Y chromosome CNV are short stature and gonadal dysgenesis. If there is an increase of Y chromosome CNV detected by CNV-seq, FISH is recommended to classify the structural variation of Y chromosome.
Humans
;
Female
;
DNA Copy Number Variations
;
In Situ Hybridization, Fluorescence
;
Retrospective Studies
;
Chromosomes, Human, Y
;
Turner Syndrome
10.Incidence and genetic reproductive characteristics of AZFc microdeletion among patients with azoospermia or severe oligospermia.
Chiyan ZHOU ; Hui WANG ; Qin ZHU ; Luming WANG ; Binzhen ZHU ; Xiaodan LIU
Chinese Journal of Medical Genetics 2023;40(1):26-30
OBJECTIVE:
To explore the incidence of azoospermia factor c (AZFc) microdeletion among patients with azoospermia or severe oligospermia, its association with sex hormone/chromosomal karyotype, and its effect on the outcome of pregnancy following intracytoplasmic sperm injection (ICSI) treatment.
METHODS:
A total of 1 364 males with azoospermia or severe oligospermia who presented at the Affiliated Maternity and Child Health Care Hospital of Jiaxing College between 2013 and 2020 were subjected to AZF microdeletion and chromosome karyotyping analysis. The level of reproductive hormones in patients with AZFc deletions was compared with those of control groups A (with normal sperm indices) and B (azoospermia or severe oligospermia without AZFc microdeletion). The outcome of pregnancies for the AZFc-ICSI couples was compared with that of the control groups in regard to fertilization rate, superior embryo rate and clinical pregnancy rate.
RESULTS:
A total of 51 patients were found to harbor AZFc microdeletion, which yielded a detection rate of 3.74%. Seven patients also had chromosomal aberrations. Compared with control group A, patients with AZFc deletion had higher levels of PRL, FSH and LH (P < 0.05), whilst compared with control group B, only the PRL and FSH were increased (P < 0.05). Twenty two AZFc couples underwent ICSI treatment, and no significant difference was found in the rate of superior embryos and clinical pregnancy between the AZFc-ICSI couples and the control group (P > 0.05).
CONCLUSION
The incidence of AZFc microdeletion was 3.74% among patients with azoospermia or severe oligospermia. AZFc microdeletion was associated with chromosomal aberrations and increased levels of PRL, FSH and LH, but did not affect the clinical pregnancy rate after ICSI treatment.
Child
;
Humans
;
Male
;
Female
;
Pregnancy
;
Azoospermia/genetics*
;
Oligospermia/genetics*
;
Incidence
;
Chromosome Deletion
;
Chromosomes, Human, Y/genetics*
;
Semen
;
Infertility, Male/genetics*
;
Chromosome Aberrations
;
Follicle Stimulating Hormone/genetics*

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