Recombination of a maternal pericentric inversion results in 22q13 deletion syndrome

We describe a 10-month-old boy with 22q13 deletion syndrome. Chromosomal analysis showed a partial duplication of 22p11.2-pter and a terminal deletion of 22q13.31-qter. Maternal chromosomal analysis showed a pericentric inversion of chromosome 22, with breakpoints at p11.2 and q13.31 [inv(22)(p11.2q13.31)]. The deleted chromosome resulted from a recombinant chromosome inherited from his mother. This is a rare case of 22q13 deletion syndrome associated with parental pericentric inversion of chromosome 22.     

Prenatal diagnosis of partial monosomy 18p(18p11.2-->pter) and trisomy 21q(21q22.3-->qter) with alobar holoprosencephaly and premaxillary agenesis

A prenatal diagnosis of partial monosomy 18p(18p11.2-->pter) and trisomy 21q(21q22.3-->qter) in a fetus with alobar holoprosencephaly (HPE) and premaxillary agenesis (PMA) but without the classical Down syndrome phenotype is reported. A 27-year-old primigravida woman was referred for genetic counselling at 21 weeks' gestation due to sonographic findings of craniofacial abnormalities. Level II ultrasonograms manifested alobar HPE and median orofacial cleft. Cytogenetic analysis and fluorescence in situ hybridization (FISH) on cells obtained from amniocentesis revealed partial monosomy 18p and a cryptic duplication of 21q,46,XY,der(18)t(18;21)(p11.2;q22.3), resulting from a maternal t(18;21) reciprocal translocation. The breakpoints were ascertained by molecular genetic analysis. The pregnancy was terminated. Autopsy showed alobar HPE with PMA, pituitary dysplasia, clinodactyly and classical 18p deletion phenotype but without the presence of major typical phenotypic features of Down syndrome. The phenotype of this antenatally diagnosed case is compared with those observed in six previously reported cases with monosomy 18p due to 18;21 translocation. The present study is the first report of concomitant deletion of HPE critical region of chromosome 18p11.3 and cryptic duplication of a small segment of distal chromosome 21q22.3 outside Down syndrome critical region. The present study shows that cytogenetic analyses are important in detecting chromosomal aberrations in pregnancies with prenatally detected craniofacial abnormalities, and adjunctive molecular investigations are useful in elucidating the genetic pathogenesis of dysmorphism.     

Prenatal diagnosis of mosaic ring chromosome 22 associated with cardiovascular abnormalities and intrauterine growth restriction

OBJECTIVES: To present the prenatal diagnosis and perinatal findings of mosaic ring chromosome 22. CASE: Amniocentesis was performed at 18 gestational weeks because of an advanced maternal age. Cytogenetic analysis of the cultured amniotic fluid cells revealed mosaicism for ring chromosome 22, 45,XX,-22[6]/46,XX,r(22)(p13q13.31)[15]. Abnormal fetal sonographic findings included small for gestational age, a ventricular septal defect, and truncus arteriosus. The pregnancy was terminated. Additional phenotypic findings included hypertelorism, epicanthal folds, and abnormal ears. Cytogenetic analysis of the cord blood lymphocytes revealed a complex mosaic karyotype, 45,XX,-22[7]/46,XX,r(22)(p13q13.31)[82]/46,XX,idic r(22)(p13q13.31;p13q13.31)[11]. Cytogenetic analysis of the hepatocytes also revealed mosaic r(22) with mosaicism for idic r(22) and monosomy 22. The deletion of distal 22q and the duplication of 22q11.2 on idic r(22), and the distal 22q deletion on r(22) were demonstrated by fluorescent in situ hybridization (FISH) analysis using 22q terminal probes at 22q13 and a DiGeorge syndrome critical region probe at 22q11.2. The breakpoint on distal 22q13 and the extent of the duplication of 22q on idic r(22) was determined by examining polymorphic markers specific for chromosome 22 using quantitative fluorescent polymerase chain reaction assays. The chromosomal aberration was of maternal origin. CONCLUSION: Molecular and FISH studies allow a better delineation of some prenatally detected aneuploidy syndromes and help elucidate the genetic pathogenesis. Fetuses having mosaic r(22) with a low level mosaicism for r(22) duplication/deletion may present cardiovascular abnormalities and intrauterine growth restriction on prenatal ultrasound.     

De novo monosomy 9p24.3-pter and trisomy 17q24.3-qter characterised by microarray comparative genomic hybridisation in a fetus with an increased nuchal translucency

OBJECTIVES: Increased nuchal translucency (NT) during the first trimester of pregnancy is a useful marker to detect chromosomal abnormalities. Here, we report a prenatal case with molecular cytogenetic characterisation of an abnormal derivative chromosome 9 identified through NT. METHODS: Amniocentesis was performed because of an increased NT (4.4 mm) and showed an abnormal de novo 46,XX,add(9)(p24.3) karyotype. To characterise the origin of the small additional material on 9p, we performed a microarray comparative genomic hybridisation (microarray CGH) using a genomic DNA array providing an average of 1 Mb resolution. RESULTS: Microarray CGH showed a deletion of distal 9p and a trisomy of distal 17q. These results were confirmed by FISH analyses. Microarray CGH provided accurate information on the breakpoint regions and the size of both distal 9p deletion and distal 17q trisomy. The fetus was therefore a carrier of a de novo derivative chromosome 9 arising from a t(9;17)(p24.3;q24.3) translocation and generating a monosomy 9p24.3-pter and a trisomy 17q24.3-qter. CONCLUSION: This case illustrates that microarray CGH is a rapid, powerful and sensitive technology to identify small de novo unbalanced chromosomal abnormalities and can be applied in prenatal diagnosis.     

Does the number of previous miscarriages influence the incidence of chromosomal aberrations in spontaneous pregnancy loss?

Objective: Chromosomal aberrations are a common cause for miscarriage. The purpose of this study was to evaluate factors that influence the frequency of chromosomal abnormalities in miscarriages and provide clinicians with a guideline for management of such cases.

Methods: The study included 170 women who experienced pregnancy loss between the 2004 and 2014. Cytogenetic analysis of products of conception (POC) was routinely performed.

Results: Successful cytogenetic analysis was achieved in 144 cases (84%). Of these, 78 cases (54%) had a chromosomal aberration. The incidence of chromosomal aberrations was not statistically significant among patients with 1, 2, 3, 4 or?≥5 previous miscarriages (33.3%, 57.4%, 48.6%, 65.2%, and 59.1%, respectively, p?=?0.227). The F/M ratio was similar in normal and abnormal POC karyotypes (1.2:1 and 1.3:1, respectively, p?=?0.7).

Conclusion: Contrary to previous assumptions we did not find correlation between number of previous spontaneous miscarriages a women experienced and chromosomal aberration in her current miscarriage.     

Karyotype of the abortus in recurrent miscarriage

OBJECTIVE: To assess the chromosomal aberrations in the abortus in recurrent miscarriage and the live birth rate after a euploid or aneuploid miscarriage. DESIGN: Retrospective analysis. SETTING: Tertiary referral unit in university hospital. PATIENT(S): One hundred sixty-seven patients with 3 to 16 miscarriages before 20 weeks. INTERVENTION(S): Material collected at curettage from 167 abortuses was analyzed by standard G-banding techniques. MAIN OUTCOME MEASURE(S): The incidence of aberrations and the outcome of the subsequent pregnancy were assessed according to the embryonic karyotype. RESULT(S): In this study 125 specimens were successfully karyotyped. Of these, 29% (36 of 125) had chromosome aberrations; 94% of the aberrations were aneuploidy, and 6% were structural. The most prevalent anomalies were chromosome 16, 18, and 21 trisomies, triploidy, and monosomy X. After an aneuploid miscarriage, there was a 68% subsequent live birth rate (13 of 19) compared to the 41% (16 of 39) rate after a euploid abortion. CONCLUSION(S): The low (29%) incidence of aberrations indicates that alternative mechanisms may be responsible for the majority of recurrent miscarriages. These figures provide a basis for assessing the efficacy of therapy for recurrent miscarriage. If further studies confirm that patients with karyotypically abnormal fetuses have a good prognosis, an informed decision can be made as to whether further investigations and treatment should be undertaken.     

Euchromatic variants of 8q21.2 in twins

Objective

Euchromatic variants (EVs) of 8q21.2 are extremely rare chromosomal abnormalities. So, far there have only been two reports on EVs of 8q21.2. Here, we report an 8q21.2 EV detected in cultured amniotic-fluid cells of twins. It was later found to be inherited from the mother, who did not present with abnormal phenotypes.

Parental karyotype and subsequent live births in recurrent miscarriage

OBJECTIVE: To compare the subsequent live birth rate in recurrently miscarrying women with and without parental balanced chromosomal aberrations. DESIGN: Retrospective comparative cohort study. SETTING: Tertiary referral unit in a university hospital. PATIENT(S): Nine hundred sixteen patients with 3-16 miscarriages before 20 weeks: 99 patients with and 817 patients without chromosomal aberrations. INTERVENTION(S): None. MAIN OUTCOME MEASURE(S): Outcome of the subsequent pregnancy in terms of live births or repeat miscarriage. RESULT(S): Of the 916 patients, 661 subsequently conceived, 73 (73.7%) with parental chromosomal aberrations and 588 (71.9%) without aberrations. In patients with and without chromosomal aberrations, 33 of 73 pregnancies (45.2%) and 325 of 588 pregnancies (55.3%), respectively, resulted in live births. The difference is not statistically significant. There was a similar prevalence of aberrations in primary, secondary, and tertiary aborters. The prevalence of aberrations was not related to the number of previous miscarriages. Translocations, inversions, and mosaicism were followed by a similar live birth rate. CONCLUSION(S): Patients with parental chromosomal rearrangements do not have a significantly lower live birth rate than patients without aberrations. Parental karyotyping might not be a good predictor of the outcome of subsequent pregnancies.     

Molecular cytogenetic characterization of 1q42.3q44 deletion and 8q24.3 duplication in a fetus with single umbilical artery and ventricular septal defects

ObjectiveWe present prenatal diagnosis and molecular cytogenetic characterization of a chromosome 1q42.3q44 deletion and 8q24.3 duplication in a fetus with single umbilical artery and ventricular septal defects, and we discuss the genotype–phenotype correlation.Case reportHere, we describe a fetus with abnormal sonography findings showing a single umbilical artery and ventricular septal defects. Conventional karyotyping initially described the fetus as 46,XX,1q? and molecular cytogenetic analysis (CMA) revealed a 13-Mb deletion and 4.6-Mb duplication of regions 1q42.3q44 and 8q24.3, respectively. The father's karyotype was 46,XY. The mother's karyotype was 46,XX,t(1;8)(q42;q24). Therefore, the karyotype of the fetus was identified as 46,XX,der(1)t(1;8)(q42;q24) mat. After genetic counseling, the couple chose to terminate the pregnancy. We suggest that the ACTN2, RYR2 and PUF60 genes may be responsible for the ultrasound abnormalities observed in the fetus.ConclusionTo the best of our knowledge, this is the first report of a 1q deletion and 8q duplication identified by prenatal detection. The application of karyotype analysis and CMA provides more accurate characterization for unidentified chromosomal anomalies, and benefits appropriate genetic counseling in the clinic.     

Prenatal cytogenetic assessment and inv(2)(p11.2q13)

OBJECTIVES: To present a series of prenatally detected cases of recurrent pericentric inversions with euchromatic breakpoints and to review the literature to determine whether parental karyotyping is required for genetic counselling. METHODS: Cases of recurrent pericentric inversions with euchromatic breakpoints were collected from Canadian Cytogenetic Laboratories. Cases included inversions for chromosome 1(p13q21), chromosome 2(p11.2q13), chromosome 5(p13q13) and chromosome 10(p11.2q21.2). RESULTS: The incidence of de novo inv(2)(p11.2q13) was low, with one case among 91 inversions. There were no cases of de novo inv(10) (p11.2q21.2) among 17 reported and one case of de novo inv(5)(p13q13) among 21 reported. CONCLUSION: Our study, and data from the literature, suggests that most cases of inv(2)(p11.2q13) have been stably inherited, that de novo cases of inv(2) are rare and that both inherited and de novo forms are without phenotypic or developmental consequences. We suggest that parental karyotyping for cases of inv(2) is not useful in counselling as it may generate unnecessary parental anxiety over a chromosomal finding that is likely innocuous.     

Prenatal diagnosis of familial submicroscopic duplication at 18q22.3 without phenotypic abnormalities

ObjectiveTo report a case of familial submicroscopic duplication at 18q22.3 without phenotypic abnormalities.Case reportHere, we reported two different cases with novel copy number variation at chromosome 18q22.3: one carried a maternally inherited 2.36 Mb microduplication, and the other carried a patrilineally inherited 1.74 Mb microduplication. The HumanCytoSNP-12 array allows for the visualization of the CNVs and maps the breakpoints. Both parents with the microduplication at 18q22.3 as well as their foetuses had normal phenotypes; the infants were regularly followed up after one year of age, and no abnormalities were found, including abnormalities related to growth, intelligence and sexual development.ConclusionOur report showed that the duplication of 18q22.3 (chr18:68,606,012-71,287,101) might represent a benign variant.     

Syndromic encephalocele in a fetal case with a 1p35-pter deletion and a 14q32-qter duplication inherited from a maternal balanced translocation

Occipital encephalocele belongs to the family of neural tube defects, which occur in one among 2000 to 5000 live births. Syndromic encephaloceles include Meckel-Gruber syndrome and various chromosomal abnormalities. We report on a fetal case (13 WG) with bilateral cleft lip and palate, choanal atresia, occipital encephalocele, bilateral club feet, bilateral multicystic kidneys, enlarged bladder and urethral atresia. The fetal chromosome analysis showed a maternally inherited unbalanced translocation between the short arm of chromosome 1 and the long arm of chromosome 14, resulting in 1p35-pter deletion and 14q32-qter duplication (46,XY,der(1),t(1;14)(p35;q32)). Since the chromosomal breakpoints have not previously been implicated in syndromic encephalocele, this observation is of interest for the identification of other genes responsible for occipital encephalocele.     

Prenatal diagnosis of 17q12 duplication and deletion syndrome in two fetuses with congenital anomalies

ObjectiveThe objective of this study was to characterize the genetic abnormalities in two fetuses with congenital anomalies in prenatal screening.Materials and methodsThe mother of Fetus 1 was 26 years old and had a second trimester serum screening that indicated the fetus was at low risk. The prenatal ultrasound and magnetic resonance imaging (MRI) at 28 weeks of gestation showed mild ventriculomegaly, microcephaly, and agenesis of the corpus callosum. The mother of Fetus 2 was 25 years old and also had a second trimester serum screening that indicated the fetus was at low risk. The prenatal ultrasound at 32 weeks of gestation showed the presence of hyperechogenic and enlarged kidneys with multicystic renal dysplasia bilaterally and a persistent left superior vena cava (PLSVC). Both pregnant women underwent cord blood samplings because of the abnormal imaging results. Karyotype analysis revealed normal results in the two fetuses. Chromosome microarray analysis (CMA) was then performed to provide genetic analysis of the cord blood and parental blood samples. Ultimately, the pregnancies were both terminated.ResultsCMA detected a 1.56-Mb duplication at 17q12 in Fetus 1 and a 1.93-Mb deletion of 17q12 in Fetus 2. Both the duplicated and deleted regions included the HNF1B and LHX1 genes. Neither the duplication nor deletion was inherited from the parents.ConclusionThis study is the first to report the prenatal diagnosis of a 17q12 duplication syndrome. Our results further confirmed that genes in this region, including HNF1B and LHX1, are essential for normal brain and kidney development, and also indicated some genes that may be associated with the cardiovascular abnormality. Combined with imaging examination, the use of CMA will improve the diagnosis of submicroscopic chromosomal aberrations in fetuses with congenital anomalies.     

Array comparative genomic hybridization analysis of uterine leiomyosarcoma

PURPOSE: Using a genome-wide array-based comparative genomic hybridization (array-CGH), DNA copy number changes in uterine leiomyosarcoma were analyzed. MATERIALS AND METHODS: We analyzed 4 cases of uterine leiomyoma and 7 cases of uterine leiomyosarcoma. The paraffin-fixed tissue samples were microdissected under microscope and DNA was extracted. Array-based CGH and fluorescence in situ hybridization (FISH) were carried out with Genome database (Gene Ontology). RESULTS: Uterine leiomyoma showed no genetic alterations, while all of 7 cases of uterine leiomyosarcoma showed specific gains and losses. The percentage of average gains and losses were 4.86% and 15.1%, respectively. The regions of high level of gain were 7q36.3, 7q33-q35, 12q13-12q15, and 12q23.3. And the regions of homozygous loss were 1p21.1, 2p22.2, 6p11.2, 9p21.1, 9p21.3, 9p22.1, 14q32.33, and 14q32.33 qter. There were no recurrent regions of gain, but recurrent regions of loss were 1p21.1-p21.2, 1p22.3-p31.1, 9p21.2-p22.2, 10q25-q25.2, 11q24.2-q25, 13q12-q12.13, 14q31.1-q31.3, 14q32.32-q32.33, 15q11-q12, 15q13-q14, 18q12.1-q12.2, 18q22.1-q22.3, 20p12.1, and 21q22.12-q22.13. In the high level of gain regions, BAC clones encoded HMGIC, SAS, MDM2, TIM1 genes. Frequently gained BAC clone-encoded genes were TIM1, PDGFR-beta, REC Q4, VAV2, FGF4, KLK2, PNUTL1, GDNF, FLG, EXT1, WISP1, HER-2, and SOX18. The genes encoded by frequently lost BAC clones were LEU1, ERCC5, THBS1, DCC, MBD2, SCCA1, FVT1, CYB5, and ETS2/E2. A subset of cellular processes from each gene was clustered by Gene Ontology database. CONCLUSION: Using array-CGH, chromosomal aberrations related to uterine leiomyosarcoma were identified. The high resolution of array-CGH combined with human genome database would give a chance to find out possible target genes present in the gained or lost clones.     

Characterization of a balanced complex chromosomal rearrangement carrier ascertained through a fetus with dup15q26.3 and del5p15.33: case report

Abstract

Complex chromosomal rearrangements (CCRs) are structural aberrations involving more than two chromosomes which rarely appear in individuals with normal phenotypes. These individuals report fertility problems, recurrent miscarriages, or congenital anomalies in newborn offspring as a consequence of either meiotic failure or imbalanced chromosome segregation. A CCR involving chromosomes 5, 15, and 18 was discovered in a phenotypically normal man through a fetus with congenital malformations and partial trisomy of chromosome 15 and monosomy of chromosome 5. Ultrasound examination at 20 weeks of gestation showed severe oligoamnios and hydrothorax. Prenatal cytogenetic analysis and array comparative genomic hybridization (array-CGH) revealed a female fetus with dup15q26.3 and del5p15.33. We diagnosed the CCR using three-color fluorescence in situ hybridization (three-color FISH), and a balanced CCR using array-CGH and FISH was diagnosed in the paternal karyotype. The father is a carrier of a balanced translocation 46,XY,t(5;15;18)(p15.31;q26.3;p11.2). Due to the complexity of these rearrangements the diagnosis is difficult and the reproductive outcome uncertain. Reporting such rare cases is important to enable such information to be used for genetic counseling in similar situations and help estimate the risk of miscarriage or of newborns with congenital abnormalities.     

Prenatal diagnosis and molecular cytogenetic characterization of partial dup(18q)/del(18p) due to a paternal pericentric inversion 18 in a fetus with multiple anomalies

ObjectiveWe present prenatal diagnosis of rec(18)dup(18q)inv(18)(p11.2q21.2)pat owing to paternal pericentric inversion in a fetus.Case reportA 37-year-old woman was diagnosed with multiple anomalies on a prenatal ultrasound scan at 17 weeks and 5 days of gestation. She underwent amniocentesis at 20 weeks and 2 days. Conventional karyotyping of amniocyte showed 46, XX, der(18). She was thus referred for genetic counseling; cytogenetic analysis revealed a 46, XY karyotype, inv(18)(p11.2q21.2), of the father. Therefore, based on the results of the father, the fetal karyotype was defined as 46, XX, rec(18)dup(18q)inv(18)(p11.2q21.2)pat. Array comparative genomic hybridization of amniocytes to obtain specific information showed a 3-Mb deletion of 18p11.31p11.32 (136227_3100353)x1 and a 23.7-Mb duplication of 18q21.31-q23 (54222717_77957375) × 3.ConclusionMaternal serum screening produces normal results for 18p-/18q+ syndrome, but it can be diagnosed by fluorescent in situ hybridization, quantitative-fluorescent polymerase chain reaction, or array comparative genomic hybridization test by observing abnormal findings on ultrasound.     

5p15缺失综合征合并4q32重复1例临床分析与基因诊断

目的 探讨5p15缺失综合征合并4q32重复的临床特征及分子遗传学特点.方法 回顾分析1例5p15缺失综合征合并4q32重复患儿的临床资料以及分子遗传学分析资料.结果 10月龄女性患儿,具有特殊面容、发育迟缓、先天性心脏病及喉软骨发育不良等临床表现.全外显子测序和染色体组拷贝数分析精确定位拷贝数异常改变的染色体片段区域...     

Habitueller Abort – genetische Ursachen

Genetic factors play an etiologic role in sporadic and recurrent miscarriage. Fetal chromosomal anomalies are the main cause of sporadic miscarriages, whereas in recurrent miscarriages, the rate of fetal chromosomal anomalies is inversely correlated to the number of miscarriages. An abnormal karyotype is present in 3–5% of women with a diagnosis of recurrent miscarriage and their partners. Specific polymorphisms are also associated with an increased risk for recurrent miscarriage. Genetic thrombophilia conferred by carrying the factor V Leiden polymorphism is of clinical relevance for women with recurrent miscarriage due to possible treatment with heparin. Another genetic factor associated with recurrent miscarriage is skewed X-chromosome inactivation, defined as a selective inactivation of paternal or maternal X chromosomes. In addition, androgenetic anomalies such as sperm aneuploidy and sperm DNA fragmentation have been described as etiologic factors in recurrent miscarriage.     

Prenatal diagnosis of trisomy 18p and distal 21q22.3 deletion

OBJECTIVES: To present the perinatal findings and molecular cytogenetic analysis of concomitant trisomy 18p (18p11.2-->pter) and distal 21q22.3 deletion. CASE AND METHODS: A 29-year-old woman, gravida 2 para 1, underwent amniocentesis at 17 weeks' gestation because she was a carrier of a balanced reciprocal translocation, 46,XX,t(18;21)(p11.2;q22.3). Cytogenetic analysis of the cultured amniocytes revealed a karyotype of 46,XX,der(21)t(18;21)(p11.2;q22.3). The fetus had a derivative chromosome 21 with an extra short arm of chromosome 18 attached to the terminal region of the long arm of chromosome 21. Level II sonograms did not find prominent structural anomalies. The pregnancy was terminated subsequently. At autopsy, the proband displayed a mild phenotype of hypertelorism, a small mouth, micrognathia, a narrowly arched palate, low-set ears, and clinodactyly. The brain and other organs were unremarkable. Genetic marker analysis showed a distal deletion at 21q22.3 and a breakpoint between D21S53 (present) and D21S212 (absent), centromeric to the known holoprosencephaly (HPE) minimal critical region D21S113-21qter. CONCLUSION: Genetic marker analysis helps in delineating the region of deletion in prenatally detected unbalanced cryptic translocation. Fetuses with concomitant trisomy 18p and distal 21q22.3 deletion may manifest inapparent phenotypic abnormalities in utero. Haploinsufficiency of the HPE critical region at 21q22.3 may not cause an HPE phenotype.     

Prenatal diagnosis and molecular cytogenetic characterization of mosaic ring chromosome 21 associated with low PAPP-A and low PlGF in the first-trimester maternal serum screening

ObjectiveWe present diagnosis and molecular cytogenetic characterization of mosaic ring chromosome 21 [r(21)].Case reportA 17-year-old, gravida 2, para 1, woman underwent amniocentesis at 17 weeks of gestation because of an abnormal result of the first-trimester maternal serum screening for Down syndrome with a free β-hCG level of 1.736 multiples of the median (MoM), a pregnancy associated plasma protein-A (PAPP-A) level of 0.275 MoM, a placental growth factor (PlGF) level of 0.281 MoM, a Down syndrome risk of 1:222 and a preeclampsia risk of 1:175. Cytogenetic analysis of cultured amniocytes revealed the result of 46,XX,r(21) (p12q22.3)[19]/45,XX,-21[13]. Array comparative genomic hybridization (aCGH) analysis of cultured amniocytes revealed the result of arr [GRCh37] 21q11.2q22.2 (15,485,008–40,625,594) × 1～2, 21q22.2q22.3 (40,703,792–46,682,184) × 2～3, 21q22.3 (46,761,631–48,084,156) × 1, consistent with mosaic monosomy 21 and r(21) (p12q22.3). The pregnancy was subsequently terminated, and a malformed fetus was delivered with low-set ears and hypotelorism. Postnatal cytogenetic analysis revealed a karyotype of 46,XX,r(21) (p12q22.3)[30]/45,XX,-21[8]/46,XX,idic r(21) (p12q22.3)[2] in the cord blood, 46,XX,r(21) (p12q22.3)[34]/45,XX,-21[6] in the skin, 46,XX,r(21) (p12q22.3)[37]/45,XX,-21[3] in the umbilical cord and 46,XX,dup(21) (q22.2q22.3)[32]/46,XX,r(21) (p12q22.3)[8] in the placenta. aCGH analysis of cord blood revealed the result of arr 21q11.2q22.2 (15,499,847–40,662,581) × 2.3, arr 21q22.2q22.3 (40,703,792–46,682,184) × 3.6, arr 21q22.3 (46,761,632–48,090,317) × 1, consistent with mosaic duplication of 21q11.2-q22.2 and 21q22.2-q22.3, and a 1.33-Mb 21q22.3 deletion encompassing the genes of COL18A1, SLC19A1, PCBP3, COL6A1, COL6A2, FTCD, LSS, MCM3AP, YBEY, PCNT, DIP2A, S100B and PRMT2.ConclusionMosaic r(21) at amniocentesis may be associated with monosomy 21, idic r(21) and dup(21), and low PAPP-A and low PlGF in the first-trimester maternal serum screening.