Advertisement
Full lenght article| Volume 211, P1-7, April 2017

Chromosomal uniparental disomy 16 and fetal intrauterine growth restriction

  • Xie Yingjun
    Affiliations
    Key Laboratory for Major Obstetric Diseases of Guangdong Province, Key Laboratory of Reproduction and Genetics of Guangdong Higher Education Institutes, The Third Affiliated Hospital of Guangzhou Medical University, Guangzhou 510150, China
    Search for articles by this author
  • Hu Zhiyang
    Affiliations
    Obstetric Department, Shenzhen People's Hospital, The Second Clinical Medical School of Jinan University, Shenzhen 518020, China
    Search for articles by this author
  • Lin Linhua
    Affiliations
    Obstetric Department, Shenzhen People's Hospital, The Second Clinical Medical School of Jinan University, Shenzhen 518020, China
    Search for articles by this author
  • Su Fangming
    Affiliations
    Obstetric Department, Shenzhen People's Hospital, The Second Clinical Medical School of Jinan University, Shenzhen 518020, China
    Search for articles by this author
  • Huang Linhuan
    Affiliations
    Fetal Medicine Centre, Department of Obstetrics and Gynecology, The First Affiliated Hospital of Sun Yat-sen University, Guangzhou, Guangdong 510080, China
    Search for articles by this author
  • Tan Jinfeng
    Affiliations
    Gynecology Department, Department of Obstetrics and Gynecology, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou 510080, China
    Search for articles by this author
  • Pang Qianying
    Affiliations
    Key Laboratory for Major Obstetric Diseases of Guangdong Province, Key Laboratory of Reproduction and Genetics of Guangdong Higher Education Institutes, The Third Affiliated Hospital of Guangzhou Medical University, Guangzhou 510150, China
    Search for articles by this author
  • Sun Xiaofang
    Correspondence
    Corresponding author at: The Third Affiliated Hospital of Guangzhou Medical University, 63 Duobao Rd., Guangzhou 510150, China.
    Affiliations
    Key Laboratory for Major Obstetric Diseases of Guangdong Province, Key Laboratory of Reproduction and Genetics of Guangdong Higher Education Institutes, The Third Affiliated Hospital of Guangzhou Medical University, Guangzhou 510150, China
    Search for articles by this author
Published:December 22, 2016DOI:https://doi.org/10.1016/j.ejogrb.2016.12.019

      Abstract

      Background

      There is a well-documented association between prenatally diagnosed chromosomal uniparental disomy and poor pregnancy outcome.

      Methods and result

      In this study, we identified an intrauterine growth restricted fetus carrying a maternal UPD 16 with segmental hetero- and isodisomy using the Affymetrix CytoScan HD SNP-array and the UPDtool. We also performed FISH to exclude trisomy mosaicism of chr.16. We then explored the genetic mechanisms of how imprinted genes cause clinical abnormalities. Additionally, we reviewed the mUPD16 literature, compared the clinical phenotypes of our patient with other reported cases, and assessed the loss of autosomal-recessive genes in the regions of homozygosity.

      Conclusions

      Considering UPD mechanism of potential impact on the function of the placenta, the genetic composition of chromosome 16, and the information previous literature reports, we have reason to believe that UPD16 correlates with IUGR.

      Abbreviations:

      AC (abdominal circumference), BPD (biparietal diameter), CNVs (copy number variations), CDT1 (chromatin licensing and DNA replication factor 1), CMA (chromosome microarray analysis), CMV (cytomegalovirus), DMRs (differentially methylated regions), ET (embryo transfer), HC (head circumference), IUGR (intrauterine growth restriction), IVF (in vitro fertilization), UPD (uniparental disomy), OMIM (The On-Line Mendelian Inheritance in Man database), ROH (regions of homozygosity)

      Keyword

      What’s already known about this topic?

      Uniparental disomy may cause clinical abnormalities through a number of different genetic mechanisms, such as an autosomal recessive disease, mosaicism and imprinting, which produces abnormal clinical phenotypes.

      What does this study add?

      The suspected genetic mechanisms involves in the mUPD16 to cause fetal intrauterine growth restriction.

      1 Introduction

      Intrauterine growth restriction (IUGR) is a major cause of fetal and neonatal morbidity and mortality that contributes to stillbirth. IUGR can result from abnormalities in the fetus, placenta, mother or the environment. Additionally, the genetic growth potential of the fetus, the ability of the placenta to transfer oxygen and nutrients to the developing fetus, and the ability of the mother to deliver these factors to the placenta also contribute to IUGR [
      • Cox P.
      • Marton T.
      Pathological assessment of intrauterine growth restriction.
      ]. There are several chromosomal and genetic disorders associated with IUGR. These disorders include common autosomal trisomies of chromosomes 13, 18, and 21. Furthermore, triploidy with unbalanced chromosome translocations and deletions are also common genetic events [
      • Karl K.
      • Heling K.S.
      • Sarut Lopez A.
      • Thiel G.
      • Chaoui R.
      Thymic-thoracic ratio in fetuses with trisomy 21, 18 or 13.
      ,
      • Kehinde F.I.
      • Anderson C.E.
      • McGowan J.E.
      • Jethva R.N.
      • Wahab M.A.
      • Glick A.R.
      • et al.
      Co-occurrence of non-mosaic trisomy 22 and inherited balanced t(4;6)(q33;q23.3) in a liveborn female: case report and review of the literature.
      ,
      • Sienko M.
      • Petriczko E.
      • Zajaczek S.
      • Zygmunt-Gorska A.
      • Starzyk J.
      • Korpysz A.
      • et al.
      A ten-year observation of somatic development of a first group of Polish children with Silver-Russell syndrome.
      ,
      • Daniel A.
      • Wu Z.
      • Bennetts B.
      • Slater H.
      • Osborn R.
      • Jackson J.
      • et al.
      Karyotype, phenotype and parental origin in 19 cases of triploidy.
      ]. IUGR is associated with uniparental disomy (UPD) of many chromosomes including chromosome 16 [
      • Kotzot D.
      Prenatal testing for uniparental disomy: indications and clinical relevance.
      ,
      • Kotzot D.
      • Utermann G.
      Uniparental disomy (UPD) other than 15: phenotypes and bibliography updated.
      ]. Uniparental disomy may cause clinical abnormalities through a number of different genetic mechanisms. For example, patients may be affected with an autosomal recessive disease if they are homozygous for a disease-causing recessive allele [
      • Papenhausen P.R.
      • Mueller O.T.
      • Johnson V.P.
      • Sutcliffe M.
      • Diamond T.M.
      • Kousseff B.G.
      Uniparental isodisomy of chromosome 14 in two cases: an abnormal child and a normal adult.
      ]. Patients can also be affected by mosaicism for two related chromosomal patterns [
      • Neiswanger K.
      • Hohler P.M.
      • Hively-Thomas L.B.
      • McPherson E.W.
      • Hogge W.A.
      • Surti U.
      Variable outcomes in mosaic trisomy 16: five case reports and literature analysis.
      ] through imprinting, which is the most common pathogenetic mechanism that produces abnormal clinical phenotypes.
      In the current study, we used an Affymetrix CytoScan HD SNP-array for chromosome microarray analysis (CMA) and detected a segmental UPD 16 (33.7 Mb) [arr[hg19] 16p13.3p12.2(89,560-21,620,447) × 2 hmz,16q23.1q24.3(77,916,190-90,163,275) hmz] with no copy number change in a fetus presenting with severe IUGR.

      2 Materials and methods

      2.1 Clinical data

      A 34-year-old primiparous woman at 26 weeks of gestation was referred to the prenatal diagnosis clinic with complaints of fetal growth restriction. The woman had a spontaneous late abortion five years prior. This pregnancy was an in vitro fertilization (IVF) embryo transfer (ET) due to her secondary infertility. The crown-rump length of the fetus at 12+6 weeks was 63 mm. The first trimester registration examination showed that she was immune to rubella and cytomegalovirus (CMV). The patient’s blood pressure was 147/108 mmHg. The fetus had a high risk for both Down’s syndrome and open neural tube defects due to low levels of PAPPA (0.17 MoM) and high levels of both AFP (3.24 MoM) and HCG (3.6 MoM) in her first and second trimester Down’s syndrome screening tests, respectively. The morphology scan at 20+6weeks of gestation found the fetal biparietal diameter (BPD), head circumference (HC), and abdominal circumference (AC) were 39 mm (−3.4SD), 155 mm (−2.8SD), and 133 mm (−2.7SD), respectively. These measurements indicated fetal growth restriction. The fetal structure was otherwise normal. An additional ultrasound scan was performed at 24+4 weeks. The fetal BPD, HC, and AC were 51 mm (−3.3SD), 198 mm (−2.7SD) and 163 mm (−3.3SD), respectively. There was a normal volume of amniotic fluid (42 mm), which is consistent with the diagnosis of IUGR (Fig. 1). A cordocentesis was performed at 26 weeks of gestation, and the results showed no specific findings despite the dark color of the fetal blood collected from the umbilical vein. The fetal blood and amniotic fluid were sent for karyotype, CMV-DNA, CMV-IgM and IgG testing. The fetus had a normal female karyotype, and no CMV-DNA or CMV-IgM were detectable. The fetal hemoglobin was 140 g/l, and the proportion of monocytes in the fetal blood was 17%. There was an intrauterine fetal death six days after cordocentesis. The postmortem examination after induction of labor showed a normal female weighted 860 g (delivery in another hospital and no sample was available for further genetic analysis). Placenta pathology was not performed because the couple refused to do so. The stored fetal blood sample was sent for chromosome microarray (CMA) testing. All data were collected after obtaining informed consent from the patient.
      Fig. 1
      Fig. 1Growth parameters of the fetus measured at 20 weeks (blue cross) and 24 weeks (red cross) illustrated by Astraea software. (For interpretation of the references to colour in this figure legend, the reader is referred to the web version of this article.)

      2.2. CMA

      Cord blood (2 ml) was collected from the mother at 22 weeks of gestation by cordocentesis. We also collected peripheral blood specimens from both parents. The genomic DNA was extracted from the uncultured cord blood using a QIAamp DNA Blood Mini Kit [QIAGEN, Hilden, D]. The DNA (250 ng) was then amplified, labeled, and hybridized to the CytoScan HD array platform (Affymetrix, USA) according to the manufacturer's protocol. The array was designed specifically for cytogenetic research and contains more than 2,700,000 markers across the whole genome including 750,000 SNP probes and 1,950,000 probes to detect copy number variations (Cyto-arrays). The CEL files obtained by scanning the CytoScan arrays were analyzed using the Chromosome Analysis Suite software (Affymetrix, USA). The genome annotations were obtained from version GRCH37(hg19). Only qualified measures were included in our analysis. The gains and losses that affected a minimum of 50 markers in a 100 kb length were initially considered.
      The thresholds for genome-wide screening are set at >500 kb for gains, >200 kb for losses, and >5 Mb for regions of homozygosity (ROH).

      2.3. Conventional cytogenetic analysis

      Cord blood (2 ml) was collected by cordocentesis with informed consent. The sample was subjected to cord blood culture according to the standard cytogenetic protocol. A 5 ml sample of peripheral blood was collected from each parent. The blood samples were subjected to lymphocyte culture according to the standard blood cytogenetic protocol. Finally, the cultured cord blood and lymphocytes were analyzed with routine cytogenetic analysis using Giemsa-banding techniques with a resolution of 550 bands.
      We also performed FISH using the chromosome 16 centromere-specific probe CEP16 (Vysis, USA) to exclude low-level mosaicism (600 nuclei analyzed). The FISH analysis was conducted according to the manufacturer’s protocol.

      2.4. Classification of UPD using the UPDtool

      The family microarray data were processed using the standard protocols provided by the manufacturer and were then analyzed with Chromosome Analysis Suite software (Affymetrix, USA). All copy number variations (CNVs) were excluded before analysis because CNVs can interfere with UPD detection. The genotypes were exported and converted to the input format using the UPD converter tool [
      • Schroeder C.
      • Sturm M.
      • Dufke A.
      • Mau-Holzmann U.
      • Eggermann T.
      • Poths S.
      • et al.
      UPDtool: a tool for detection of iso- and heterodisomy in parent-child trios using SNP microarrays.
      ]. The UPD was detected and classified using the UPD tool available at the following link: (http://www.uni-tuebingen.de/uni/thk/de/f-genomik-software.html.)

      2.5 Bioinformatic analysis of a clinical correlation with UPD16

      We compared the clinical phenotypes of our patient who carried a maternal UPD16 with other reported patients by searching in the UPD database (http://upd-tl.com/chr16mhtml). We also searched imprinted genes in the gene imprint database (http://www.geneimprint.com) and other potential candidate genes in ROHs for autosomal recessive disorders in the On-Line Mendelian Inheritance in Man (OMIM) database (http://www.omim.org).

      3. Results

      The couple had a normal karyotype, and the karyotype of the fetus was 46,XX (Fig. 2A). The SNP-Microarray analysis of the fetus found no copy number change but two segments of UPD on chromosome 16 (16p13.3p12.2 and 16q23.1q24.3). The segments were 21.5 Mb and 12.2 Mb, respectively [arr[hg19] 16p13.3p12.2(89,560-21,620,447) × 2 hmz,16q23.1q24.3(77,916,190-90,163,275) hmz] (Fig. 3A). The FISH analysis using the CEP 16 probe on fetal blood cells showed all the detected interphase cells were normal, which excluded low-level mosaicism of trisomy 16 (Fig. 2B). The classification of UPD using the UPDtool showed there was a matUPD16 with segmental hetero- and isodisomy (Fig. 3B). The data analysis and the SNP-Microarray result of chromosome 16 indicated that the breakpoint of hetero- and isodisomy is 16p12.2 (21,620,447) and 16q23.1 (77,916,190).
      Fig. 2
      Fig. 2A. Normal karyotype of the fetus. B. FISH analysis using the CEP 16 probe on the fetus blood showed all the detected interphase cells were normal, which excludes low-level mosaicism of trisomy 16.
      Fig. 3
      Fig. 3A. SNP-Microarray analysis of the fetus found by copy number change with two segments of uniparental disomy (UPD) on chromosome 16. B. Classification of UPD using the UPDtool. FracHom (Red line) is the fraction of genotypes in 1 k window that is homozygous, FracME (Green line) is the fraction of MEs in a 1 k window, FracIdentFather (Blue line) is the fraction of genotypes within a 1 k window where both alleles are identical to the fathers’ alleles, Frac Ident Mother (Black line) is the fraction of genotypes within a 1 k window where both alleles are identical to the mothers’ allele. (For interpretation of the references to colour in this figure legend, the reader is referred to the web version of this article.)
      The bioinformatic analysis using the UPD database showed there are more than 12 matUPD16 cases with clinical findings or unclear correlation and normal karyotype (http://upd-tl.com/chr16m.html) (Table 1). There was one case of a missed abortion, and at least 4 cases were IUGR. There are two maternal imprinted genes located on chr16; ZNF597 an NAA60. There are also five predicted imprinted genes, which are SOX8, SALL1, C160rf57, ACD and FOXF1 in the gene imprint database (Table 2). The On-Line Mendelian Inheritance in Man (OMIM) database lists 5 syndromes characterized by intrauterine or prenatal growth restriction in chr16 (Table 3).
      Table 1Mat UPD cases with clinical findings or an unclear correlation and normal karyotype in UPD database (http://upd-tl.com/chr16m.html).
      NO.genderAge at diagnosisStudied materialGTG-banding resultClinical symptoms
      1femaleprenatalplacenta/missed abortion46,XXmissed abortion
      2maleprenatalAF, CH46,XYIUGR
      3n.a.postnatalPBLn.a.IUGR
      4n.a.prenatalAFn.a.IUGR; Bart's hydrops fetalis
      5n.a.postnatalPBLn.a.IUGR, transient neonatal hypoglycemia and cholestasis
      6malepostnatalPBLn.a.no IUGR; Malonyl-CoA decarboxylase deficiency (gene MLYCD in 16q23.3)
      7n.a.postnatalPBLn.a.no IUGR; macular corneal dystrophy (gene CHST6 in 16q23.1)
      8maleprenatalAF46,XYsingle umbilical arteria, single kidney, abnormal genitals. IUGR. iUPD but no gene detected
      9femalepostnatalAF; PBL46,XXno IUGR; adenine phosphoribosyltransferase deficiency (gene APRT in 16q24.3)
      10n.a.postnatalPBLn.a.no IUGR; mucopolysaccharidosis IVA (gene GALNS in 16q24.3)
      11n.a.prenatalAFn.a.no IUGR; alpha thalassemia (gene either HBA1 or HBA2 in 16p13.3)
      12female18yPBLn.a.no IUGR; atypical neuropathy (gene GAN1 in 16q23.2)
      n.a.: not assessable/assessed; AF: Amniotic fluid; PBL: Peripheral Blood; CH: chorionic villi; IUGR: Intrauterine growth restriction
      Table 2Imprinted genes on chromosome 16 identified in the gene imprint database.
      GeneLocationFunctionStatusExpressed Allele
      ZNF59716p13.3zinc finger protein 597imprintedmaternal
      NAA6016P13.3N(alpha)-acetyltransferase 60, NatF catalytic subunitpredictedpaternal
      SALL116q12.1spalt-like transcription factor 3imprintedmaternal
      SOX816p13.3SRY box 8predictedpaternal
      C16orf5716q21chromosome 16 open reading frame 57predictedmaternal
      ACD16q22.1adrenocortical dysplasia homologpredictedmaternal
      FOXF116q24forkhead box F1predictedmaternal
      Table 3There are 5 syndromes characterized by intrauterine or prenatal growth restriction in chr16.
      LocationPhenotypePhenotype MIM numberInheritancePhenotype mapping keyGene/LocusGene/Locus MIM number
      16q12.1Growth retardation, developmental delay, facial dysmorphism612938AR3FIO610966
      16q11.2Meier-Gorlin syndrome 3613803AR3ORC6607213
      16q24.3Meier-Gorlin syndrome 4613804AR3CDT1605525
      16p13.3Congenital disorder of glycosylation, type Ik608540AR3ALG1605907
      16p12.2-p11.2Chromosome 16p12.2-p11.2 deletion syndrome613604IC4
      AR: Autosomal recessive.
      IC: Isolated cases.
      4 − a contiguous gene duplication or deletion syndrome in which multiple genes are involved.
      3 − the molecular basis of the disorder is known.k

      4 Discussion

      In the current case, we identified UPD on chromosome 16 using a SNP-array. We then conducted further analyses using the UPDtool and family linkage analysis to determine there was a maternal uniparental chromosome 16 disomy (mUPD16) with a combined hetero- and isodisomy.
      UPD occurs when both members of a particular chromosome pair derive from the same parent and there is no contribution from the other parent [
      • Shaffer L.G.
      • Agan N.
      • Goldberg J.D.
      • Ledbetter D.H.
      • Longshore J.W.
      • Cassidy S.B.
      American College of Medical Genetics statement of diagnostic testing for uniparental disomy.
      ]. Fetal UPD 16 has previously been associated with the following fetal anomalies: IUGR, dilated digestive tract, gallbladder agenesis, and hypoplastic cerebellum with abnormal gyration of the vermis [
      • Neiswanger K.
      • Hohler P.M.
      • Hively-Thomas L.B.
      • McPherson E.W.
      • Hogge W.A.
      • Surti U.
      Variable outcomes in mosaic trisomy 16: five case reports and literature analysis.
      ,
      • Moradkhani K.
      • Puechberty J.
      • Blanchet P.
      • Coubes C.
      • Lallaoui H.
      • Lewin P.
      • et al.
      Mosaic trisomy 16 in a fetus: the complex relationship between phenotype and genetic mechanisms.
      ]. Nonhomologous recombination can lead to segmental uniparental disomy. If uniparental disomy occurs during meiotic recombination of an entire chromosome then the results may be a combination of isodisomic or heterodisomic segment types.In addition, as for the fetus normal development, the normal function of placenta should be taken into consideration. The mechanism mediating matUPD16 may involves the oocyte nondisjunction events in meiosis II, resulting in an ovum of 24,X,+16. In the very early stages of implantation or embryogenesis, the aberrant egg was fertilized with a normal 23,Y sperm cell, and trisomy 16 rescued the onset of embryogenesis. The paternal chromosome 16 was then lost to the placenta with trisomy 16 or confined placental mosaicism (CPM), allowing the embryo to survive and producing a maternal uniparental disomy 16. In this study, this fetus with unexplained first and mid-trimester elevation in maternal serum hCG and/or maternal serum AFP. These findings indicated there was placental insufficiency beginning in the first trimester which may be correlated with CPM [
      • Mardy A.
      • Wapner R.J.
      Confined placental mosaicism and its impact on confirmation of NIPT results.
      ,
      • Wilkins-Haug L.
      • Quade B.
      • Morton C.C.
      Confined placental mosaicism as a risk factor among newborns with fetal growth restriction.
      ]. Furthermore, 4/12 cases in the UPD database were IUGR for matUPD16. This result suggests that matUPD16 may be correlated with IUGR (Table 1). As a result, UPD should be considered as a factor for IUGR.
      The pathogenesis of UPD is determined by both epigenetic imprinting and unmasking of autosomal-recessive diseases [
      • Tiranti V.
      • Lamantea E.
      • Uziel G.
      • Zeviani M.
      • Gasparini P.
      • Marzella R.
      • et al.
      Leigh syndrome transmitted by uniparental disomy of chromosome 9.
      ]. In addition, the database shows the genes CDT1 and ALG1 located at 16q24.3 and 16p13.3 are associated with autosomal-recessive diseases (Table 3), and these genes are found in the ROH of our present case. Although the family history is normal, we cannot exclude the potential effect of homozygous mutation on CDT1 (chromatin licensing and DNA replication factor 1) and ALG1 (chitobiosyldiphosphodolichol beta-mannosyltransferase) [
      • Rohlfing A.K.
      • Rust S.
      • Reunert J.
      • Tirre M.
      • Du Chesne I.
      • Wemhoff S.
      • et al.
      ALG1-CDG: a new case with early fatal outcome.
      ,
      • Bicknell L.S.
      • Bongers E.M.
      • Leitch A.
      • Brown S.
      • Schoots J.
      • Harley M.E.
      • et al.
      Mutations in the pre-replication complex cause Meier-Gorlin syndrome.
      ]. The result of the UPD database search indicated matUPD16 is correlated with IUGR. However, it is unlikely that the same mutation caused IUGR in all matUPD16 cases. Furthermore, the mechanism of loss of autosomal-recessive genes is a rare cause of cystic fibrosis in affected children with uniparental disomy for chromosome 7 [
      • Falk M.J.
      • Curtis C.A.
      • Bass N.E.
      • Zinn A.B.
      • Schwartz S.
      Maternal uniparental disomy chromosome 14: case report and literature review.
      ]. Thus, epigenetic imprinting is a more plausible explanation for disease pathogenesis.
      The clinical phenotype resulting from uniparental disomy in imprinted regions of the genome depends on whether a particular parent-specific allele is absent or overexpressed. Genomic imprinting is an epigenetic process mediated by DNA methylation and repressive histone modifications that repress one allele. This repression results in parent-of-origin specific monoallelic expression. There are currently two imprinted genes located on chromosome 16 (Table 2): ZNF597 and NAA60. Both of these genes are maternally expressed. A homozygous mutation of ZNF597 is embryonic lethal due to failed embryonic organization before cardiogenesis at embryonic day 7.5 in mice. This result confirmed the high expression of ZNF597 in placenta and its critical role in placental development and suggests the gene performs a functional role in development [
      • Tanabe Y.
      • Hirano A.
      • Iwasato T.
      • Itohara S.
      • Araki K.
      • Yamaguchi T.
      • et al.
      Molecular characterization and gene disruption of a novel zinc-finger protein, HIT-4, expressed in rodent brain.
      ]. ZNF597 is located at 16p13.3 and was found to be an imprinted gene with a critical role in placental development [
      • Tanabe Y.
      • Hirano A.
      • Iwasato T.
      • Itohara S.
      • Araki K.
      • Yamaguchi T.
      • et al.
      Molecular characterization and gene disruption of a novel zinc-finger protein, HIT-4, expressed in rodent brain.
      ,
      • Barbaux S.
      • Gascoin-Lachambre G.
      • Buffat C.
      • Monnier P.
      • Mondon F.
      • Tonanny M.B.
      • et al.
      A genome-wide approach reveals novel imprinted genes expressed in the human placenta.
      ,
      • Choufani S.
      • Shapiro J.S.
      • Susiarjo M.
      • Butcher D.T.
      • Grafodatskaya D.
      • Lou Y.
      • et al.
      A novel approach identifies new differentially methylated regions (DMRs) associated with imprinted genes.
      ,
      • Nakabayashi K.
      • Trujillo A.M.
      • Tayama C.
      • Camprubi C.
      • Yoshida W.
      • Lapunzina P.
      • et al.
      Methylation screening of reciprocal genome-wide UPDs identifies novel human-specific imprinted genes.
      ]. Nakabayashi et al. analyzed CpG dinucleotides present in the human genome for imprinted differentially methylated regions (DMRs) by methylation beadchip microarray analysis. The results indicated the ZNF597 gene is imprinted [
      • Nakabayashi K.
      • Trujillo A.M.
      • Tayama C.
      • Camprubi C.
      • Yoshida W.
      • Lapunzina P.
      • et al.
      Methylation screening of reciprocal genome-wide UPDs identifies novel human-specific imprinted genes.
      ]. A previous study demonstrated that once imprinted genes were identified many were found to have important placental functions [
      • Tunster S.J.
      • Jensen A.B.
      • John R.M.
      Imprinted genes in mouse placental development and the regulation of fetal energy stores.
      ,
      • Kagami M.
      • Matsuoka K.
      • Nagai T.
      • Yamanaka M.
      • Kurosawa K.
      • Suzumori N.
      • et al.
      Paternal uniparental disomy 14 and related disorders: placental gene expression analyses and histological examinations.
      ,
      • Bressan F.F.
      • De Bem T.H.
      • Perecin F.
      • Lopes F.L.
      • Ambrosio C.E.
      • Meirelles F.V.
      • et al.
      Unearthing the roles of imprinted genes in the placenta.
      ]. According to the conflict hypothesis, paternal genes enhance and maternal genes suppress fetal growth. During midgestation the fetus acquires resources for growth via the placenta. Thus, the organ must express genes from both genomes.
      Chromosomal microarray analysis and single nucleotide polymorphism analysis can detect both deletions and uniparental disomies in cases with a long-contiguous stretch of homozygosity that is isodisomic [
      • Yingjun X.
      • Yi Z.
      • Jianzhu W.
      • Yunxia S.
      • Yongzhen C.
      • Liangying Z.
      • et al.
      Prader-Willi syndrome with a long-Contiguous stretch of homozygosity not covering the critical region.
      ]. However, this approach cannot indicate heterodisomic regions. In addition, microsatellite analysis and methylation specific tests are labor intensive and expensive genome wide screening tools for examining UPDs due to the limited number of markers that are available for each chromosome. In contrast, the UPDtool is a computational tool for the detection and classification of UPD in trio SNP-microarray experiments. This tool analyzes UPD stretches and correctly identifies the breakpoints within a chromosome. These regions can then be evaluated precisely using microsatellite analysis [
      • Schroeder C.
      • Sturm M.
      • Dufke A.
      • Mau-Holzmann U.
      • Eggermann T.
      • Poths S.
      • et al.
      UPDtool: a tool for detection of iso- and heterodisomy in parent-child trios using SNP microarrays.
      ].

      5 Conclusion

      Our present study demonstrates that the trio SNP-microarray data combined with the UPDtool can detect isodisomic and heterodisomic UPD. We employed further bioinformatic analyses to improve the phenotype and genome type correlations for ROHs. mUPD16 could be a genetic factor for IUGR leading to stillbirth. However, we did not obtain fetal placenta for further genetic testing, such as chromosomal mosaicism detection. We could use genetic detection studies in our fetal sample to evaluate the prognosis of the fetus and genetic consulting for family planning.

      Ethical approval

      Ethical approval was obtained for this study from the Ethics Committee of the First Affiliated Hospital of Sun Yat-sen University (IRB 201301).

      Funding

      This study was supported by the National Natural Science Foundation Committee of China (NSFC-81500974 to Xie Yingjun); Shenzhen Science and Technology Innovation Committee (JCYJ20150403101146312 to Hu Zhiyang).

      Availability of data and materials

      Chromosome Analysis Suite Software, Version 3.1 (http://www.affymetrix.com/support/technical/software_downloads.affx)

      Authors’ contributions

      Hu Zhiyang and Lin Linhua carried out the molecular genetic studies, participated in the sequence alignment and drafted the manuscript. Su Fangming, Huang Linhuan and Tan Jinfeng participated in clinical data collection. Pang Qianying participated in the Conventional cytogenetic analysis. Sun Xiaofang carried out the chromosome microarray analysis. Xie Yingjun conceived of the study, and participated in its design and coordination and helped to draft the manuscript. All authors read and approved the final manuscript.

      Consent for publish

      Consent to publish has been obtained from the patient.

      Conflicts of interest

      The authors declare that they have no competing interests.

      Acknowledgement

      We would like to thank the staff of the genetic center for providing patient data.

      References

        • Cox P.
        • Marton T.
        Pathological assessment of intrauterine growth restriction.
        Best Pract Res Clin Obstetr Gynaecol. 2009; 23: 751-764
        • Karl K.
        • Heling K.S.
        • Sarut Lopez A.
        • Thiel G.
        • Chaoui R.
        Thymic-thoracic ratio in fetuses with trisomy 21, 18 or 13.
        Ultrasound Obstetr Gynecol. 2012; 40: 412-417
        • Kehinde F.I.
        • Anderson C.E.
        • McGowan J.E.
        • Jethva R.N.
        • Wahab M.A.
        • Glick A.R.
        • et al.
        Co-occurrence of non-mosaic trisomy 22 and inherited balanced t(4;6)(q33;q23.3) in a liveborn female: case report and review of the literature.
        Am J Med Genet A. 2014; 164: 3187-3193
        • Sienko M.
        • Petriczko E.
        • Zajaczek S.
        • Zygmunt-Gorska A.
        • Starzyk J.
        • Korpysz A.
        • et al.
        A ten-year observation of somatic development of a first group of Polish children with Silver-Russell syndrome.
        Neuro Endocrinol Lett. 2014; 35: 306-313
        • Daniel A.
        • Wu Z.
        • Bennetts B.
        • Slater H.
        • Osborn R.
        • Jackson J.
        • et al.
        Karyotype, phenotype and parental origin in 19 cases of triploidy.
        Prenatal Diagn. 2001; 21: 1034-1048
        • Kotzot D.
        Prenatal testing for uniparental disomy: indications and clinical relevance.
        Ultrasound Obstetr Gynecol. 2008; 31: 100-105
        • Kotzot D.
        • Utermann G.
        Uniparental disomy (UPD) other than 15: phenotypes and bibliography updated.
        Am J Med Genet A. 2005; 136: 287-305
        • Papenhausen P.R.
        • Mueller O.T.
        • Johnson V.P.
        • Sutcliffe M.
        • Diamond T.M.
        • Kousseff B.G.
        Uniparental isodisomy of chromosome 14 in two cases: an abnormal child and a normal adult.
        Am J Med Genet. 1995; 59: 271-275
        • Neiswanger K.
        • Hohler P.M.
        • Hively-Thomas L.B.
        • McPherson E.W.
        • Hogge W.A.
        • Surti U.
        Variable outcomes in mosaic trisomy 16: five case reports and literature analysis.
        Prenatal Diagn. 2006; 26: 454-461
        • Schroeder C.
        • Sturm M.
        • Dufke A.
        • Mau-Holzmann U.
        • Eggermann T.
        • Poths S.
        • et al.
        UPDtool: a tool for detection of iso- and heterodisomy in parent-child trios using SNP microarrays.
        Bioinformatics. 2013; 29: 1562-1564
        • Shaffer L.G.
        • Agan N.
        • Goldberg J.D.
        • Ledbetter D.H.
        • Longshore J.W.
        • Cassidy S.B.
        American College of Medical Genetics statement of diagnostic testing for uniparental disomy.
        Genet Med. 2001; 3: 206-211
        • Moradkhani K.
        • Puechberty J.
        • Blanchet P.
        • Coubes C.
        • Lallaoui H.
        • Lewin P.
        • et al.
        Mosaic trisomy 16 in a fetus: the complex relationship between phenotype and genetic mechanisms.
        Prenatal Diagn. 2006; 26: 1179-1182
        • Mardy A.
        • Wapner R.J.
        Confined placental mosaicism and its impact on confirmation of NIPT results.
        Am J Med Genet C Semin Med Genet. 2016; 172: 118-122
        • Wilkins-Haug L.
        • Quade B.
        • Morton C.C.
        Confined placental mosaicism as a risk factor among newborns with fetal growth restriction.
        Prenatal Diagn. 2006; 26: 428-432
        • Tiranti V.
        • Lamantea E.
        • Uziel G.
        • Zeviani M.
        • Gasparini P.
        • Marzella R.
        • et al.
        Leigh syndrome transmitted by uniparental disomy of chromosome 9.
        J Med Genet. 1999; 36: 927-928
        • Rohlfing A.K.
        • Rust S.
        • Reunert J.
        • Tirre M.
        • Du Chesne I.
        • Wemhoff S.
        • et al.
        ALG1-CDG: a new case with early fatal outcome.
        Gene. 2014; 534: 345-351
        • Bicknell L.S.
        • Bongers E.M.
        • Leitch A.
        • Brown S.
        • Schoots J.
        • Harley M.E.
        • et al.
        Mutations in the pre-replication complex cause Meier-Gorlin syndrome.
        Nat Genet. 2011; 43: 356-359
        • Falk M.J.
        • Curtis C.A.
        • Bass N.E.
        • Zinn A.B.
        • Schwartz S.
        Maternal uniparental disomy chromosome 14: case report and literature review.
        Pediatr Neurol. 2005; 32: 116-120
        • Tanabe Y.
        • Hirano A.
        • Iwasato T.
        • Itohara S.
        • Araki K.
        • Yamaguchi T.
        • et al.
        Molecular characterization and gene disruption of a novel zinc-finger protein, HIT-4, expressed in rodent brain.
        J Neurochem. 2010; 112: 1035-1044
        • Barbaux S.
        • Gascoin-Lachambre G.
        • Buffat C.
        • Monnier P.
        • Mondon F.
        • Tonanny M.B.
        • et al.
        A genome-wide approach reveals novel imprinted genes expressed in the human placenta.
        Epigenetics. 2012; 7: 1079-1090
        • Choufani S.
        • Shapiro J.S.
        • Susiarjo M.
        • Butcher D.T.
        • Grafodatskaya D.
        • Lou Y.
        • et al.
        A novel approach identifies new differentially methylated regions (DMRs) associated with imprinted genes.
        Genome Res. 2011; 21: 465-476
        • Nakabayashi K.
        • Trujillo A.M.
        • Tayama C.
        • Camprubi C.
        • Yoshida W.
        • Lapunzina P.
        • et al.
        Methylation screening of reciprocal genome-wide UPDs identifies novel human-specific imprinted genes.
        Hum Mol Genet. 2011; 20: 3188-3197
        • Tunster S.J.
        • Jensen A.B.
        • John R.M.
        Imprinted genes in mouse placental development and the regulation of fetal energy stores.
        Reproduction. 2013; 145: R117-37
        • Kagami M.
        • Matsuoka K.
        • Nagai T.
        • Yamanaka M.
        • Kurosawa K.
        • Suzumori N.
        • et al.
        Paternal uniparental disomy 14 and related disorders: placental gene expression analyses and histological examinations.
        Epigenetics. 2012; 7: 1142-1150
        • Bressan F.F.
        • De Bem T.H.
        • Perecin F.
        • Lopes F.L.
        • Ambrosio C.E.
        • Meirelles F.V.
        • et al.
        Unearthing the roles of imprinted genes in the placenta.
        Placenta. 2009; 30: 823-834
        • Yingjun X.
        • Yi Z.
        • Jianzhu W.
        • Yunxia S.
        • Yongzhen C.
        • Liangying Z.
        • et al.
        Prader-Willi syndrome with a long-Contiguous stretch of homozygosity not covering the critical region.
        J Child Neurol. 2014;