Genetic analysis of a child with mosaicism Turner syndrome / 中华医学遗传学杂志

OBJECTIVE@#To explore the genetic characteristics of a child with mosaicism Turner syndrome.@*METHODS@#A child who had presented at Linyi People's Hospital on May 19, 2022 due to short stature was selected as the study subject. The child was subjected to combined chromosomal karyotyping, fluorescence in situ hybridization (FISH), and chromosomal microarray analysis (CMA).@*RESULTS@#The child was found to have a 46,X,i(X)(q10)[94]/45,X[6] karyotype. The result of FISH was nucish(XYpter,XYqter)1[78]/(XYpter)1,(XYqter)3[122]. CMA result for her peripheral blood sample was arr[hg19]Xp22.33p11.1(168551_58526888)×1, and that for her oral mucosal cells was arr[hg19]Xp22.33p11.1(168551_58526888)1-2,Xq11.2q28(63000001_155233098)×2-3. By integrating the above findings, her molecular karyotype was determined as mos 46,X,i(X)(q10)[94]/45,X[6].arr[hg19]Xp22.33p11.1(168551_58526888)×1-2,Xq11.2q28(63000001_155233098)×2-3.nucish(XYpter)1,(XYqter)3[122]/(XYpter,XYqter)1[78], which has indicated mosaicism Turner syndrome.@*CONCLUSION@#The 46,X,i(X)(q10)/45,X mosaicism probably underlay the pathogenesis in this child.

Genetic analysis of a Chinese pedigree affected with overgrowth syndrome due to a small supernumerary marker chromosome / 中华医学遗传学杂志

OBJECTIVE@#To carry out genetic analysis for a Chinese pedigree affected with intellectual disability and overgrowth due to a supernumerary marker chromosome (sSMC).@*METHODS@#A pedigree which had presented at Jiaxing Maternity and Child Health Care Hospital on August 31, 2021 was selected as the study subject, for which chromosomal karyotyping, single nucleotide polymorphism-based microarray (SNP-array), and fluorescence in situ hybridization (FISH) were carried out in combination.@*RESULTS@#SNP-array analysis showed that the proband and his sister had both harbored a 16.1 Mb duplication which encompassed the critical region of 15q26 overgrowth syndrome. FISH confirmed that the proband was 47,XX,+neo(15)(qter→q25.3:)mat, her mother was 47,XX,del(15)(q25.3:),+neo(15)(qter→q25.3:), whilst her father was normal.@*CONCLUSION@#Application of multiple genetic techniques has facilitated delineation of the origin of sSMC and reliable genetic counseling for this pedigree.

Genetic analysis of two cases with MYC "negative" Burkitt lymphoma / 中华医学遗传学杂志

OBJECTIVE@#To carry out combined genetic analysis on two patients suspected for Burkitt lymphoma to facilitate their diagnosis and treatment.@*METHODS@#G banded karyotyping and interphase and metaphase fluorescence in situ hybridization (FISH) were used to detect the specific sites of chromosomes by using separate and fusion probes.@*RESULTS@#The separate probe showed no presence of MYC gene abnormality, while fusion probe confirmed the IGH::MYC translocation in the samples. Combined with the clinical features and pathological characteristics, the two patients were finally diagnosed with Burkitt lymphoma, which was confirmed by targeted capture next generation sequencing.@*CONCLUSION@#The separate probe for the MYC gene has some shortcomings and should be used together with dual fusion probe to improve the accuracy of diagnosis.

Genetic analysis of a child with Focal segmental glomerulosclerosis and neurodevelopmental syndrome / 中华医学遗传学杂志

OBJECTIVE@#To explore the genetic characteristics of a child with Focal segmental glomerulosclerosis and neurodevelopmental syndrome (FSGSNEDS).@*METHODS@#A child with FSGSNEDS who had visited Shengli Oilfield Central Hospital on September 15, 2019 was selected as the study subject. Clinical data of the child was collected, and trio-whole exome sequencing (trio-WES), Sanger sequencing, chromosomal karyotyping analysis, and copy number variation sequencing (CNV-seq) were used to analyze the child and his parents.@*RESULTS@#The child, a 3-year-old boy, had manifested developmental delay, nephrotic syndrome, and epilepsy. Trio-WES and Sanger sequencing showed that he has carried a heterozygous c.1375C＞T (p.Q459*) variant of the TRIM8 gene, for which both his parents were of the wild type. Based on guidelines from the American College of Medical Genetics and Genomics (ACMG), the variant was predicted to be pathogenic. No abnormality was found in the chromosomal karyotyping and CNV-seq results of the child and his parents.@*CONCLUSION@#The child was diagnosed with FSGSNEDS, for which the c.1375C＞T variant of the TRIM8 gene may be accountable.

Clinical phenotype and genetic analysis of a fetus with recombinant chromosome 8 syndrome / 中华医学遗传学杂志

OBJECTIVE@#To explore the clinical characteristics and molecular genetic mechanism of a fetus with recombinant chromosome 8 (Rec8) syndrome.@*METHODS@#A fetus who was diagnosed with Rec8 syndrome at the Provincial Hospital Affiliated to Shandong First Medical University on July 20, 2021 due to high risk for sex chromosomal aneuploidy indicated by non-invasive prenatal testing (NIPT) (at 21st gestational week) was selected as the study subject. Clinical data of the fetus was collected. G-banded karyotyping and chromosomal microarray analysis (CMA) were carried out on the amniotic fluid sample. Peripheral blood samples of the couple were also subjected to G banded karyotyping analysis.@*RESULTS@#Prenatal ultrasonography at 23rd gestational week revealed hypertelorism, thick lips, renal pelvis separation, intrahepatic echogenic foci, and ventricular septal defect. The karyotype of amniotic fluid was 46,XX,rec(8)(qter→q22.3::p23.1→qter), and CMA was arr[GRCh37]8p23.3p23.1(158049_6793322)×1, 8q22.3q24.3(101712402_146295771)×3. The karyotype of the pregnant woman was 46,XX,inv(8)(p23.1q22.3), whilst that of her husband was normal.@*CONCLUSION@#The Rec8 syndrome in the fetus may be attributed to the pericentric inversion of chromosome 8 in its mother. Molecular testing revealed that the breakpoints of this Rec8 have differed from previously reported ones.

Clinical and genetic analysis of a case of Turner syndrome with rapidly progressive puberty and a literature review / 中华医学遗传学杂志

OBJECTIVE@#To investigate the clinical features and genetic etiology of a case of Turner syndrome (TS) with rapidly progressive puberty.@*METHODS@#A child who had presented at the Pediatric Endocrinology Clinic of the Shenzhen People's Hospital on January 19, 2022 was selected as the study subject. Clinical data of the child were collected. Peripheral blood sample of the child was subjected to chromosomal microarray analysis (CMA) and multiple ligation-dependent probe amplification (MLPA). Previous studies related to TS with rapidly progressive puberty were retrieved from the CNKI, Wanfang Data Knowledge Service Platform, Boku, CBMdisc and PubMed databases with Turner syndrome and rapidly progressive puberty as the keywords. The duration for literature retrieval was set from November 9, 2021 to May 31, 2022. The clinical characteristics and karyotypes of the children were summarized.@*RESULTS@#The child was a 13-year-and-2-month-old female. She was found to have breast development at 9, short stature at 10, and menarche at 11. At 13, she was found to have a 46,X,i(X)(q10) karyotype. At the time of admission, she had a height of 143.5 cm (< P3), with 6 ~ 8 nevi over her face and right clavicle. She also had bilateral simian creases but no saddle nasal bridge, neck webbing, cubitus valgus, shield chest or widened breast distance. She had menstruated for over 2 years, and her bone age has reached 15.6 years. CMA revealed that she had a 58.06 Mb deletion in the Xp22.33p11.1 region and a 94.49 Mb duplication in the Xp11.1q28 region. MLPA has confirmed monosomy Xp and trisomy Xq. A total of 13 reports were retrieved from the CNKI, Wanfang Data Knowledge Service Platform, Boku, CBMdisc and PubMed databases, which had included 14 similar cases. Analysis of the 15 children suggested that their main clinical manifestations have included short stature and growth retardation, and their chromosomal karyotypes were mainly mosaicisms.@*CONCLUSION@#The main clinical manifestations of TS with rapidly progressive puberty are short stature and growth retardation. Deletion in the Xp22.33p11.1 and duplication in the Xp11.1q28 probably underlay the TS with rapid progression in this child, which has provided a reference for clinical diagnosis and genetic counselling for her.

The value of combined CNV-Seq and chromosomal karyotyping for the detection of amniocytic mosaicisms and a literature review / 中华医学遗传学杂志

OBJECTIVE@#To assess the value of combined copy number variation sequencing (CNV-seq) and chromosomal karyotyping for the diagnosis of amniocytic mosaicisms, in addition with a literature review.@*METHODS@#Forty cases of amniocytic mosaicisms detected at the Genetic and Prenatal Diagnosis Center of the First Affiliated Hospital of Zhengzhou University from January 2018 to December 2021, in addition with 245 mosaicisms retrieved from 11 recent literature were evaluated in terms of detection rate, consistency rate, and pregnancy outcomes.@*RESULTS@#The detection rate of amniocytic mosaicisms was 0.46% (40/8 621) in our center. And its consistency rate with chromosomal karyotyping was 75.0% (30/40). After genetic counseling, 30 (75.0%) couples had opted to terminate the pregnancy, 5 (12.5%) had decided to continue with the pregnancy, 3 (7.5%) fetuses were born alive, and 2 cases (5.0%) were lost in touch. By contrast, 245 cases (0.39%) of mosaicisms were identified among 63 577 amniotic samples, with a consistency rate of 62.8% (103/164) with other techniques. Among these, 114 cases (55.1%) were terminated, 75 (36.2%) were born alive, and 18 (8.7%) were lost during the follow up.@*CONCLUSION@#Combined CNV-seq and chromosomal karyotyping has a high value for the detection of amniotic mosaicisms.

Application of fluorescence in situ hybridization combined with chromosomal karyotyping analysis in children with disorders of sex development due to sex chromosome abnormalities / 中华医学遗传学杂志

OBJECTIVE@#To retrospectively analyze sex chromosomal abnormalities and clinical manifestations of children with disorders of sex development (DSD).@*METHODS@#A total of 14 857 children with clinical features of DSD including short stature, cryptorchidism, hypospadia, buried penis and developmental delay were recruited from Zhengzhou Children's Hospital from January 2013 to March 2022. Fluorescence in situ hybridization (FISH) and chromosomal karyotyping were carried out for such children.@*RESULTS@#In total 423 children were found to harbor sex chromosome abnormalities, which has yielded a detection rate of 2.85%. There were 327 cases (77.30%) with Turner syndrome and a 45,X karyotype or its mosaicism. Among these, 325 were females with short stature as the main clinical manifestation, 2 were males with short stature, cryptorchidism and hypospadia as the main manifestations. Sixty-two children (14.66%) had a 47,XXY karyotype or its mosaicism, and showed characteristics of Klinefelter syndrome (KS) including cryptorchidism, buried penis and hypospadia. Nineteen cases (4.49%) had sex chromosome mosaicisms (XO/XY), which included 11 females with short stature, 8 males with hypospadia, and 6 cases with cryptorchidism, buried penis, testicular torsion and hypospadia. The remainder 15 cases (3.55%) included 9 children with a XYY karyotype or mosaicisms, with main clinical manifestations including cryptorchidisms and hypospadia, 4 children with a 47,XXX karyotype and clinical manifestations including short stature and labial adhesion, 1 child with a 46,XX/46,XY karyotype and clinical manifestations including micropenis, hypospadia, syndactyly and polydactyly, and 1 case with XXXX syndrome and clinical manifestations including growth retardation.@*CONCLUSION@#Among children with DSD due to sex chromosomal abnormalities, sex chromosome characteristics consistent with Turner syndrome was most common, among which mosaicism (XO/XX) was the commonest. In terms of clinical manifestations, the females mainly featured short stature, while males mainly featured external genital abnormalities. Early diagnosis and treatment are particularly important for improving the quality of life in such children.

Phenotypic and genetic analysis of a child with partial trisomy 7q / 中华医学遗传学杂志

OBJECTIVE@#To define the nature and origin of a chromosomal aberration in a child with unexplained growth and development retardation, and to analyze its genotype-phenotype correlation.@*METHODS@#A child who had presented at the Affiliated Children's Hospital of Zhengzhou University on July 9, 2019 was selected as the study subject. Chromosomal karyotypes of the child and her parents were determined with routine G-banding analysis. Their genomic DNA was also analyzed with single nucleotide polymorphism array (SNP array).@*RESULTS@#Karyotyping analysis combined with SNP array suggested that the chromosomal karyotype of the child was 46,XX,dup(7)(q34q36.3), whilst no karyotypic abnormality was found in either of her parents. SNP array has identified a de novo 20.6 Mb duplication at 7q34q36.3 [arr[hg19] 7q34q36.3(138335828_158923941)×3] in the child.@*CONCLUSION@#The partial trisomy 7q carried by the child was rated as a de novo pathogenic variant. SNP array can clarify the nature and origin of chromosomal aberrations. Analysis of the correlation between genotype and phenotype can facilitate the clinical diagnosis and genetic counseling.

Genetic analysis of a fetus with de novo 46,X,der(X)t(X;Y)(q26;q11) / 中华医学遗传学杂志

OBJECTIVE@#To carry out prenatal genetic testing for a fetus with de novo 46,X,der(X)t(X;Y)(q26;q11).@*METHODS@#A pregnant woman who had visited the Birth Health Clinic of Lianyungang Maternal and Child Health Care Hospital on May 22, 2021 was selected as the study subject. Clinical data of the woman was collected. Peripheral blood samples of the woman and her husband and umbilical cord blood of the fetus were collected and subjected to conventional G-banded chromosomal karyotyping analysis. Fetal DNA was also extracted from amniotic fluid sample and subjected to chromosomal microarray analysis (CMA).@*RESULTS@#For the pregnant women, ultrasonography at 25th gestational week had revealed permanent left superior vena cava and mild mitral and tricuspid regurgitation. G-banded karyotyping analysis showed that the pter-q11 segment of the fetal Y chromosome was connected to the Xq26 of the X chromosome, suggesting a Xq-Yq reciprocal translocation. No obvious chromosomal abnormality was found in the pregnant woman and her husband. The CMA results showed that there was approximately 21 Mb loss of heterozygosity at the end of the long arm of the fetal X chromosome [arr [hg19] Xq26.3q28(133912218_154941869)×1], and 42 Mb duplication at the end of the long arm of the Y chromosome [arr [hg19] Yq11.221qter(17405918_59032809)×1]. Combined with the search results of DGV, OMIM, DECIPHER, ClinGen and PubMed databases, and based on the guidelines from the American College of Medical Genetics and Genomics (ACMG), the deletion of arr[hg19] Xq26.3q28(133912218_154941869)×1 region was rated as pathogenic, and the duplication of arr[hg19] Yq11.221qter(17405918_59032809)×1 region was rated as variant of uncertain significance.@*CONCLUSION@#The Xq-Yq reciprocal translocation probably underlay the ultrasonographic anomalies in this fetus, and may lead to premature ovarian insufficiency and developmental delay after birth. Combined G-banded karyotyping analysis and CMA can determine the type and origin of fetal chromosomal structural abnormalities as well as distinguish balanced and unbalanced translocations, which has important reference value for the ongoing pregnancy.

Prenatal diagnosis and genetic analysis for two Chinese pedigrees carrying large fragment deletions of 13q21 / 中华医学遗传学杂志

OBJECTIVE@#To explore the strategies of prenatal diagnosis and genetic counseling for fetuses of two families with large deletions of 13q21.@*METHODS@#Two singleton fetuses who were diagnosed with chromosome 13 microdeletions by non-invasive prenatal testing (NIPT) at Ningbo Women and Children's Hospital in March 2021 and December 2021 respectively were selected as the study subjects. Chromosomal karyotyping and chromosomal microarray analysis (CMA) were carried on amniotic samples. Peripheral blood samples were collected from the two couples for CMA assay to determine the origin of abnormal chromosomes identified in the fetuses.@*RESULTS@#The karyotypes of the two fetuses were both normal. CMA revealed that they have respectively harbored heterozygous deletions spanning 11.935 Mb at 13q21.1q21.33 and 10.995 Mb at 13q14.3q21.32, which were respectively inherited from their mother and father. Both deletions had low gene density and lacked haploinsufficient genes, and were predicted to be likely benign variants based on database and literature search. Both couples had opted to continue with the pregnancy.@*CONCLUSION@#The deletions of the 13q21 region in both families may be of benign variants. As the follow-up time was short, there was no sufficient evidence for the determination of pathogenicity, though our finding may still provide a basis for the prenatal diagnosis and genetic counseling.

Clinical characteristics and genetic analysis of two children with Autosomal dominant mental retardation type 21 due to variants of CTCF gene / 中华医学遗传学杂志

OBJECTIVE@#To explore the clinical and genetic characteristics of two children with developmental delay.@*METHODS@#Two children who had presented at the Children's Hospital Affiliated to Shandong University on August 18, 2021 were enrolled as the study subjects. Clinical and laboratory examination, chromosomal karyotyping and high-throughput sequencing were carried out for both children.@*RESULTS@#Both children had a 46,XX karyotype. High-throughput sequencing showed that they have respectively carried a c.489delG (p.Q165Rfs*14) and a c.1157_1158delAT (p.Y386Cfs*22) frameshifting variant of the CTCF gene, both had a de novo origin and were unreported previously.@*CONCLUSION@#The CTCF gene variants probably underlay the development delay in the two children. Above discovery has enriched the mutational spectrum of the CTCF gene and has important implications for revealing the genotype-phenotype correlation for similar patients.

Clinical analysis of monochorionic-diamniotic twins with genetic discordance / 中华医学遗传学杂志

OBJECTIVE@#To explore the genetic etiology of 5 cases of monochorionic-diamniotic (MCDA) with genetic discordance.@*METHODS@#148 cases of MCDA twins who were diagnosed by amniocentesis at the Maternal and Child Health Care Hospital of Guangxi Zhuang Autonomous Region from January 2016 to June 2020 were selected as the study subjects. Relevant clinical data of the pregnant women were collected, and amniotic fluid samples of the twins were collected separately. Chromosomal karyotyping analysis and single nucleotide polymorphism array (SNP array) assay were carried out.@*RESULTS@#The results of chromosomal karyotyping analysis showed that 5 of the MCDA twins had inconsistent chromosome karyotypes, with an incidence of 3.4% (5/148). SNP array assay showed that 3 fetuses were mosaics.@*CONCLUSION@#Genetic discordance occurs among MCDA twins, and prenatal counseling for such cases should be given by doctors with experience in medical genetics and fetal medicine, and personalized clinical management should be recommended.

Genetic analysis of a Fra(16)(q22) fragile site in a female with secondary infertility / 中华医学遗传学杂志

OBJECTIVE@#To explore the genetic basis for a Fra(16)(q22)/FRA16B fragile site in a female with secondary infertility.@*METHODS@#The 28-year-old patient was admitted to Chengdu Women's and Children's Central Hospital on October 5, 2021 due to secondary infertility. Peripheral blood sample was collected for G-banded karyotyping analysis, single nucleotide polymorphism array (SNP-array), quantitative fluorescent polymerase chain reaction (QF-PCR) and fluorescence in situ hybridization (FISH) assays.@*RESULTS@#The patient was found to harbor 5 mosaic karyotypes involving chromosome 16 in a total of 126 cells, which yielded a karyotype of mos 46,XX,Fra(16)(q22)[42]/46,XX,del(16)(q22)[4]/47,XX,del(16),+chtb(16)(q22-qter)[4]/46,XX,tr(16)(q22)[2]/46,XX[71]. No obvious abnormality was found by SNP-array, QF-PCR and FISH analysis.@*CONCLUSION@#A female patient with FRA16B was identified by genetic testing. Above finding has enabled genetic counseling of this patient.

The role of jigsaw karyotype analysis in the teaching of chromosomal recognition / 中华医学遗传学杂志

Karyotype analysis is the basic method in cytogenetics, and is also recognized as the "gold standard" for diagnosing chromosomal disorders. The teaching and training for traditional karyotyping analysis is time-consuming and even boring. The individual's ability for mastering the chromosome morphology can vary greatly. Therefore, it is necessary to improve the teaching method. On the basis of the traditional method, we have added auxiliary analysis software during the teaching. This type of splicing karyotype teaching has increased the students' interest and improved their ability for karyotyping, allowing them to quickly remember the characteristic bands of chromosomes. Through enhanced memory of a large number of karyotypic images, the students' ability to recognize individual chromosomes has improved.

Application of fluorescence in situ hybridization technique to verify the clonalities of non-clonal cytogenetic abnormalities identified in Myelodysplastic syndrome / 中华医学遗传学杂志

OBJECTIVE@#To assess the value of fluorescence in situ hybridization (FISH) technique for the verification of the clonalities of non-clonal cytogenetic abnormalities (n-CCA) identified by conventional chromosome banding analysis (CBA) in patients with Myelodysplastic syndrome (MDS).@*METHODS@#Clinical data and results of karyotyping and FISH assays for 91 patients of MDS with n-CCA identified by CBA were retrospectively analyzed. In total 94 non-clonal +8, 5q-, -7/7q- or 20q- were detected by CBA, among which 43 (45.7%) were verified to be clonal abnormalities by FISH.@*RESULTS@#The detection rates for +8, 5q-, -7/7q- and 20q- by FISH were 47.6% (30/63), 25% (2/8), 41.7% (5/12), 40% (2/5) and 66.7% (4/6), respectively, with the positive cells accounting for 4% to 90% of all counted cells, with a median value of 7%. The 91 patients were divided into three groups including ≥ 20, 10 ~< 20 and < 10 based on the numbers of metaphase cells in CBA, and the detection rates by FISH for the three groups were 43.7% (31/71), 33.3% (3/9) and 63.6% (7/11), respectively, which showed no statistically difference (P > 0.05). Continuous CBA and FISH surveys were conducted for 26 patients who received supportive treatment, and the results revealed that 91.7% (11/12) of FISH-verified positive abnormalities had persisted, whereas 92.9% (13/14) of the n-CCA verified as negative by FISH was transient.@*CONCLUSION@#Nearly half of the CBA identified n-CCA have been verified as clonal aberrations by FISH, and the FISH detection rate showed no correlation with the number of metaphase cells. FISH test is strongly recommended for verifying the clonalities of n-CCA detected by CBA, and continuous cytogenetic survey of the patients with MDS is necessary.

Application of low-depth whole genome sequencing for copy number variation analysis in children with disorders of sex development / 中华医学遗传学杂志

OBJECTIVE@#To assess the value of copy number variation sequencing (CNV-seq) for the diagnosis of children with disorders of sex development (DSD).@*METHODS@#Five children with DSD who presented at the First Affiliated Hospital of Zhengzhou University from October 2019 to October 2020 were enrolled. In addition to chromosomal karyotyping, whole exome sequencing (WES), SRY gene testing, and CNV-seq were also carried out.@*RESULTS@#Child 1 and 2 had a social gender of female, whilst their karyotypes were both 46,XY. No pathogenic variant was identified by WES. The results of CNV-seq were 46,XY,+Y (1.4) and 46,XY,-Y (0.75), respectively. The remaining three children have all carried an abnormal chromosome Y. Based on the results of CNV-seq, their karyotypes were respectively verified as 45,X[60]/46,X,del(Y)(q11.221)[40], 45,X,16qh+[76]/46,X,del(Y)(q11.222),16qh+[24], and 45,X[75]/46,XY[25].@*CONCLUSION@#CNV-seq may be used to verify the CNVs on the Y chromosome among children with DSD and identify the abnormal chromosome in those with 45,X/46,XY. Above results have provided a basis for the clinical diagnosis and treatment of such children.

Genetic features of a case with mosaic ring chromosome 4 and a review of the literature / 中华医学遗传学杂志

OBJECTIVE@#To explore the genetic basis, clinical phenotype and pathogenesis for a child with mosaicism ring chromosome 4.@*METHODS@#Clinical data of the child was collected. Peripheral blood chromosomal karyotype G banding analysis, chromosomal microarray analysis (CMA), fluorescence in situ hybridization (FISH) were carried out for the child, in addition with a review of the literature.@*RESULTS@#The child was born full-term with low birth weight, facial dysmorphism, patent ductus arteriosus and ventricular septal defect. His karyotype was determined as mos46,XY,r(4)(p16.3q35.2)[259]/45,XY,-4[25]/47,XY,r(4)(p16.3q35.2), +r(4)(p16.3q35.2)[8]/46,XY,der(4)del(4)(p16.3)inv(4)(p16.3q31.1)[6]/46,XY,dic?r(4;4)(p16.3q35.2;p16.3q35.2)[4]/48,XY,r(4)(p16.3q35.2),+r(4)(p16.3q35.2)×2[3]/46,XY,r(4)(p1?q2?)[2]; CMA result was arr[GRCH37]4p16.3(68 345-2 981 614)×1; FISH result was 45,XY,-4[12]/45,XY,-4×2,+mar1.ish r1(4)(WHS-,D4Z1+)[1]/ 46,XY,-4,+mar1.ishr1(4)(WHS-,D4Z1+)[73]/46,XY,-4,+mar2.ishr2(4)(WHS-,D4Z1++)[1]/47,XY,-4,+mar1×2.ishr1(4) (WHS-, D4Z1+)×2[4]/46,XY,del(4)(p16.3).ish del(4)(p16.3)(WHS-,D4Z1+)[9].@*CONCLUSION@#In this case, the ring chromosome 4 as a de novo variant has produced a number of cell lines during embryonic development and given rise to mosaicism. The clinical phenotype of ring chromosome 4 is variable. The instability of the ring chromosome itself, presence of mosaicism, chromosome breakpoint and range of deletion and/or duplication may all affect the ultimate phenotype.

Prenatal diagnosis and genetic analysis of a rare case with 8p deletion and duplication / 中华医学遗传学杂志

OBJECTIVE@#To explore the genetic etiology for a child featuring mental retardation, language delay and autism.@*METHODS@#G-banding chromosomal karyotyping and single nucleotide polymorphism array (SNP-array) were carried out for the child and her parents.@*RESULTS@#The child was found to have a 46,XX,dup(8p?) karyotype, for which both of her parents were normal. SNP-array revealed that the child has harbored a 6.8 Mb deletion in 8p23.3p23.1 and a 21.8 Mb duplication in 8p23.1p12, both of which were verified as de novo pathogenic copy number variants.@*CONCLUSION@#The clinical features of the child may be attributed to the 8p deletion and duplication. SNP-array can facilitate genetic diagnosis for children featuring mental retardation in conjunct with other developmental anomalies.