Study of a fetus with confined placental mosaicism for trisomy 2 in conjunct with fetal uniparental disomy and a literature review / 中华医学遗传学杂志

OBJECTIVE@#To carry out genetic analysis for a fetus with confined placental mosaicism (CPM) for trisomy 2 (T2) in conjunct with fetal uniparental disomy (UPD).@*METHODS@#Amniocentesis and chromosomal karyotyping was carried out for a pregnant woman with a high risk for chromosome 2 anomalies indicated by non-invasive prenatal testing (NIPT). Single nucleotide polymorphism array (SNP-array) and trio-whole exome sequencing (Trio-WES) were carried out. Ultrasonography was used to closely monitor the fetal growth. Multifocal sampling of the placenta was performed after delivery for copy number variation sequencing (CNV-seq).@*RESULTS@#The fetus was found to have a normal chromosomal karyotype. SNP-array has revealed multiple regions with loss of heterozygosity (LOH) on chromosome 2. Trio-WES confirmed the presence of maternal UPD for chromosome 2. Ultrasonography has revealed intrauterine growth restriction and oligohydramnios. Intrauterine fetal demise had occurred at 23+4 weeks of gestation. Pathological examination had failed to find salient visceral abnormality. The placenta was proved to contain complete T2 by CNV-seq.@*CONCLUSION@#T2 CPM can cause false positive result for NIPT and may be complicated with fetal UPD, leading to adverse obstetric outcomes such as intrauterine growth restriction, oligohydramnios and intrauterine fetal demise.

Clinical and genetic analysis of a child with 2q37 deletion syndrome resulting from a translocation involving chromosome satellite / 中华医学遗传学杂志

OBJECTIVE@#To carry out cyto- and molecular genetic testing for a child featuring facial dysmorphism and attention deficit and hyperactive disorder.@*METHODS@#The child was subjected to routine peripheral blood lymphocyte chromosomal karyotyping, fluorescence in situ hybridization (FISH) and single nucleotide polymorphism array (SNP-array) analyses.@*RESULTS@#The child's facial dysmorphism included low-set ears, curly ear auricle, protuberance of eyebrow arch, nostril notch, short and flat philtrum and thin upper lip. SNP-array revealed that he has carried a 4.883 Mb deletion at 2q37. His chromosomal karyotype was ultimately determined as 45, XY, der(2;21) (2pter→ 2q37.3::21p13→ 21p10::20p10→ 20pter), der(20) (21qter→ 21q10::20q10→ 20qter).@*CONCLUSION@#A rare case of 2q37 deletion syndrome involving three chromosomes was discovered. Combined use of various cyto- and molecular genetic techniques is crucial for the diagnosis of chromosomal abnormalities with complex structures.

Phenotypic and genotypic analysis of a girl carrying a 2q22.3 microduplication encompassing the MBD5 gene / 中华医学遗传学杂志

OBJECTIVE@#To carry out single nucleotide polymorphism (SNP)-based chromosome microarray analysis (CMA) for a boy featuring global developmental delay.@*METHODS@#The SNP array was conducted for the child, and real-time PCR was used to validate its result and identify the origin of pathological copy number variants.@*RESULTS@#SNP array revealed that the patient has carried a de novo 2.5 Mb duplication at 2q22.3q23.3, which encompassed ACVR2A, KIF5C, MBD5, EPC2, LYPD6, LYPD6, MMADHC and ORC4 genes. Literature review suggested that the MBD5 gene from the duplicated region may have predisposed to the global developmental delay shown by the girl.@*CONCLUSION@#The patient's clinical phenotype was consistent to that of 2q23 duplication, for which the MBD5 gene may play a key role. CMA has provided an important tool for the diagnosis of patients with global developmental delay.

Phenotypic and genetic analysis of a sibpair with partial deletion of SATB2 gene caused by 2q33.1 microdeletion / 中华医学遗传学杂志

OBJECTIVE@#To analyze the genotype and phenotype of a sibpair with partial deletion of SATB2 gene caused by 2q33.1 microdeletion.@*METHODS@#Both children have featured mental retardation and development delay, and were subjected to karyotyping, single nucleotide microarray (SNP array) and real-time fluorescence quantitative PCR analysis. Karyotyping and SNP Array analysis were also carried out on their parents to verify the origin of mutation.@*RESULTS@#Both sibs had a normal karyotype. SNP array showed that sib 1 had arr[hg19]2q33.1(200 192 328 - 200 197 269)×1 (4.9 kb), 2q35 (218 105 663 - 218 816 675)×3 (711 kb), while sib 2 had arr[hg19]2q33.1(200 192 328 - 200 197 269)×1 (4.9 kb), 2q35 (218 105 663-218 810 908)×3 (705.2 kb). The deletion has partially overlapped with that of 2q33.1 microdeletion syndrome and involved part of the SATB2 gene. The result of real-time fluorescence quantitative PCR assay was consistent with that of SNP assay. The duplication has originated from their father and has not been associated with any disease phenotypen.@*CONCLUSION@#Both sibs have carried partial deletion of SATB2 gene and had similar clinical phenotypes. Haploinsufficiency of such gene probably underlies the clinical manifestations in both patients.

Analysis of SATB2 gene mutation in a child with Glass syndrome / 中华医学遗传学杂志

OBJECTIVE@#To analyze the clinical characteristics and genetic basis of a child affected with Glass syndrome.@*METHODS@#Clinical manifestations and auxiliary examination results of the child were analyzed. Potential mutation was detected with next generation sequencing and validated by Sanger sequencing.@*RESULTS@#The child has featured growth and mental retardation, delayed speech, cleft palate, crowding of teeth, and downslanting palpebral fissures. DNA sequencing revealed a de novo heterozygous missense mutation c.1166G>A (p.R389H) in exon 8 of the SATB2 gene in the child.@*CONCLUSION@#The heterozygous mutation c.1166G>A (p.R389H) of the SATB2 gene probably account for the Glass syndrome in the patient.

Influence of uniparental disomy on the conclusion of paternity testing / 中华医学遗传学杂志

OBJECTIVE@#To explore the influence of uniparental disomy (UPD) on bipartite and tripartite paternity testing.@*METHODS@#Two cases of paternity testing were analyzed by multiplex amplification and capillary electrophoresis typing. Suspected UPD was verified by using single nucleotide polymorphism array (SNP array). Parental power index was calculated by using a bipartite or tripartite model.@*RESULTS@#The two cases were found to harbor respectively three short tandem repeats on chromosome 2 and two short tandem repeats on chromosome 15. SNP array verified that both cases were of UPD. Case 1 had a parental power index of 122274987565.23 by a tripartite model, while case 2 had a parental power index of 13500.8463 by a bipartite model. Based on the technical specification, the conclusions supported a biological parent-child relationship in both cases.@*CONCLUSION@#UPD may lead to misjudgment of paternity testing. The possibility of UPD should be considered when certain loci which do not conform to Mendelian inheritance have aggregated to one chromosome.

Clinical features of carriers of reciprocal chromosomal translocations involving chromosome 2: report of nine cases and review of the literature

ABSTRACT Objective: To explore the clinical features of carriers of chromosome 2 translocations, enabling informed genetic counseling of these patients. Materials and Methods: Eighty-two male carriers of a translocation who were infertile or receiving fertility counseling were recruited. Cytogenetic analyses were performed using G-banding. A search of PubMed was performed to determine whether the identified translocations on chromosome 2 are involved in male infertility. The relationships of translocation breakpoints with male infertility and recurrent pregnancy loss were analyzed. Results: Of the 82 translocation carriers, 9 (11%) were carriers of a chromosome 2 translocation. Four cases had oligozoospermia or infertility, while five had normal semen. In an analysis of the literature, 55 patients who were carriers of chromosome 2 translocations were also reviewed. Breakpoints at 2p13 and 2q31 were observed in six patients each, and were the most common. Breakpoints at 2p23, 2p13, 2p11.2, 2q31, and 2q37 were associated to both pre-gestational and gestational infertility, while other breakpoints were associated with gestational infertility. Conclusions: All breakpoints at chromosome 2 were correlated with gestational infertility. Carriers of chromosome 2 translocations should therefore receive counseling to continue with natural conception and use of different technologies available via assisted reproductive technology, such as preimplantation genetic diagnosis.

X-linked Hypophosphatemic Rickets, del(2)(q37.1;q37.3) Deletion Syndrome and Mosaic Turner Syndrome, mos 45,X/46,X, del(2)(q37.1;q37.3) in a 3-year-old Female

There are currently no published cases that report concomitant Turner syndrome (TS), 2q37 deletion syndrome and X-linked hypophosphatemic rickets (XLH). Interestingly, since the clinical phenotypes of TS and 2q37 deletion syndrome overlap, the correct diagnosis may be missed without a standardized approach to genetic testing consisting of both karyotype and microarray. Both chromosome anomalies have been associated with short stature and a variety of skeletal abnormalities however to date no reports have associated these syndromes in association with a phosphate regulating endopeptidase homolog, X-linked (PHEX) gene deletion resulting in XLH. We report a 3-year-old female with 3 concurrent genetic disorders including a 9.98 Mb terminal deletion of chromosome 2: del(2)(q37.1;q37.3), XLH secondary to a small microdeletion of part of the PHEX gene, and mosaic TS (mos 45,X[32]/46,X[18]). This is the first case report of a patient with 2q37 deletion syndrome and mosaic TS (mos 45,X[32]/46,X[18]) found to have XLH secondary to an interstitial constitutional PHEX gene deletion. Her severe phenotype and multiple genotypic findings reinforce the importance of thorough genetic testing in the setting of complicated phenotypic presentations.

Constitutional Chromosomal Abnormality Identified in a Sibling Donor After Bone Marrow Stem Cell Transplantation in a Pediatric Patient with Acute Megakaryoblastic Leukemia

No abstract available.

Phenotypic and genetic analysis of a girl with multiple congenital deformities due to 2p15-p16.1 microdeletion syndrome / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To determine the origin of chromosomal aberration for a girl with mental retardation and multiple congenital deformities.</p><p><b>METHODS</b>The karotypes of the girl and her parents were analyzed with routine G-banding .Their genomic DNA was also analyzed with array comparative genomic hybridization (aCGH). Short tandem repeats (STR) were used to confirm the results of aCGH.</p><p><b>RESULTS</b>There were no karyotypic abnormality detected at cytogenetic level. aCGH identified a de novo 1.28 Mb deletion at 2p15-p16.1 in the girl. The results of the STR confirmed the deletion affected the maternal chromosome.</p><p><b>CONCLUSION</b>The de novo interstitial 2p15-p16.1 deletion may cause the mental retardation and multiple congenital deformities. chr2:60.5-61.5 Mb may be the minimal common region of 2p15-p16.1 microdeletion syndrome.</p>

First Korean Case of SATB2-Associated 2q32-q33 Microdeletion Syndrome

No abstract available.

Genetic diagnosis and analysis of related genes for a pedigree with 2p25 and 12p13 cryptic rearrangements / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To analyze chromosome aberration in a child with mental retardation and abnormalities and its parents.</p><p><b>METHODS</b>Chromosome G banding, multiplex ligation-dependent probe amplification, fluorescence in situ hybridization and single nucleotide polymorphisms array were employed for analysis.</p><p><b>RESULTS</b>Karyotype analysis revealed that the child was 46,XX and the father was 46,XY, while the mother was 46,XX, add (12)(p13). Subtelomeric region analysis with MLPA displayed that the child has reduced ACP1 gene copy number in 2p25 region and increased SLC6A12,KDM5A gene copy numbers in 12p11 region. SNP-array has fine mapped the duplication to 12p13.33-p12.3, a 15.142 Mb region, and a deletion to 2p25.3 for 3.194 Mb, which resulted in duplication of 9 genes including SLC6A12 as well as deletion of 11 genes including SNTG2, respectively. FISH analysis revealed that the child was 46,XX,ish,der(2),t(2;12)(p25;p13)mat, or partial monosomy 2p25 and partial trisomy 12p13. In addition,the mother was a carrier with cryptic balanced translocation chromosome, 46,XX,isht(2;12) (p25;p13). Mental abnormalities and retardation of the child may be attributed to heterozygous deletion of SNTG2, MYT1L genes and duplication of SLC6A12 gene.</p><p><b>CONCLUSION</b>Combined use of MLPA, FISH and SNP-array can facilitate accurate diagnosis of cryptic rearrangement at genomic level.</p>

Genome-Wide Association Study of Lung Cancer in Korean Non-Smoking Women

Lung cancer in never-smokers ranks as the seventh most common cause of cancer death worldwide, and the incidence of lung cancer in non-smoking Korean women appears to be steadily increasing. To identify the effect of genetic polymorphisms on lung cancer risk in non-smoking Korean women, we conducted a genome-wide association study of Korean female non-smokers with lung cancer. We analyzed 440,794 genotype data of 285 cases and 1,455 controls, and nineteen SNPs were associated with lung cancer development (P < 0.001). For external validation, nineteen SNPs were replicated in another sample set composed of 293 cases and 495 controls, and only rs10187911 on 2p16.3 was significantly associated with lung cancer development (dominant model, OR of TG or GG, 1.58, P = 0.025). We confirmed this SNP again in another replication set composed of 546 cases and 744 controls (recessive model, OR of GG, 1.32, P = 0.027). OR and P value in combined set were 1.37 and < 0.001 in additive model, 1.51 and < 0.001 in dominant model, and 1.54 and < 0.001 in recessive model. The effect of this SNP was found to be consistent only in adenocarcinoma patients (1.36 and < 0.001 in additive model, 1.49 and < 0.001 in dominant model, and 1.54 and < 0.001 in recessive model). Furthermore, after imputation with HapMap data, we found regional significance near rs10187911, and five SNPs showed P value less than that of rs10187911 (rs12478012, rs4377361, rs13005521, rs12475464, and rs7564130). Therefore, we concluded that a region on chromosome 2 is significantly associated with lung cancer risk in Korean non-smoking women.

Combined Genome-Wide Linkage and Association Analyses of Fasting Glucose Level in Healthy Twins and Families of Korea

This study was undertaken to identify genetic polymorphisms that are associated with the risk of an elevated fasting glucose (FG) level using genome-wide analyses. We explored a quantitative trait locus (QTL) for FG level in a genome-wide study from a Korean twin-family cohort (the Healthy Twin Study) using a combined linkage and family-based association analysis approach. We investigated 1,754 individuals, which included 432 families and 219 pairs of monozygotic twins. Regions of chromosomes 2q23.3-2q31.1, 15q26.1-15q26.3, 16p12.1, and 20p13-20p12.2, were found to show evidence of linkage with FG level, and several markers in these regions were found to be significantly associated with FG level using family-based or general association tests. In particular, a single-nucleotide polymorphism (rs6138953) on the PTPRA gene in the 20p13 region (combined P = 1.8 x 10(-6)) was found to be associated with FG level, and the PRKCB1 gene (in 16p12.1) to be possibly associated with FG level. In conclusion, multiple regions of chromosomes 2q23.3-2q31.1, 15q26.1-15q26.3, 16p12.1, and 20p13-20p12.2 are associated with FG level in our Korean twin-family cohort. The combined approach of genome-wide linkage and family-based association analysis is useful to identify novel or known genetic regions concerning FG level in a family cohort study.

Genome-Wide Association Study of Orthostatic Hypotension and Supine-Standing Blood Pressure Changes in Two Korean Populations

Orthostatic hypotension (OH) is defined by a 20-mm Hg difference of systolic blood pressure (dtSBP) and/or a 10-mm Hg difference of diastolic blood pressure (dtDBP) between supine and standing, and OH is associated with a failure of the cardiovascular reflex to maintain blood pressure on standing from a supine position. To understand the underlying genetic factors for OH traits (OH, dtSBP, and dtDBP), genome-wide association studies (GWASs) using 333,651 single nucleotide polymorphisms (SNPs) were conducted separately for two population-based cohorts, Ansung (n = 3,173) and Ansan (n = 3,255). We identified 8 SNPs (5 SNPs for dtSBP and 3 SNPs for dtDBP) that were repeatedly associated in both the Ansung and Ansan cohorts and had p-values of <1 x 10(-5) in the meta-analysis. Unfortunately, the SNPs of the OH case control GWAS did not pass our p-value criteria. Four of 8 SNPs were located in the intergenic region of chromosome 2, and the nearest gene (CTNNA2) was located at 1 Mb of distance. CTNNA2 is a linker between cadherin adhesion receptors and the actin cytoskeleton and is essential for stabilizing dendritic spines in rodent hippocampal neurons. Although there is no report about the function in blood pressure regulation, hippocampal neurons interact primarily with the autonomic nervous system and might be related to OH. The remaining SNPs, rs7098785 of dtSBP trait and rs6892553, rs16887217, and rs4959677 of dtDBP trait were located in the PIK3AP1 intron, ACTBL2-3' flanking, STAR intron, and intergenic region, respectively, but there was no clear functional link to blood pressure regulation.

One case of 2q37 deletion syndrome: clinical and genetic diagnosis / 中华儿科杂志

<p><b>OBJECTIVE</b>To diagnose a new born baby with 2q37 deletion syndrome by comprehensive use of cytogenetic and molecular techniques and to investigate the phenotype characteristics and applicability of array-comparative genomic hybridization (array-CGH) and multiplex ligation-dependent probe amplification (MLPA) for detection of this syndrome.</p><p><b>METHOD</b>Following conventional chromosome preparation, G banded karyotyping was performed.Genomic DNA was extracted using standard procedures, which were then analyzed by array-CGH and MLPA.</p><p><b>RESULT</b>The patient presented with a typical face, special fist posture and congenital heart disease in 2q37 deletion syndrome. A 4.709 Mb deletion at 2q37.3 (chr2:237, 967, 852-242, 677, 269.NCBI36/hg18, including genes from COL6A3 toPDCD1) was detected by array-CGH. The results of MLPA and G banded karyotyping confirmed the existence of this deletion.</p><p><b>CONCLUSION</b>2q37.3 deletion was determined to be the cryptic cause of this case.2q37 deletion syndrome has some clinically recognizable characteristics. And array-CGH is a powerful technique for the accurate diagnosis and genotype-phenotype correlation study of this syndrome.</p>

Patient Characteristics and Treatment of Hallux Polydactyly Associated with Varus Deformity / 대한정형외과학회잡지

PURPOSE: To evaluate patient characteristics such as deformity type, associated disease, and family history, and results of treatment of pre-axial polydactyly with hallux varus deformity. MATERIALS AND METHODS: We carried out a retrospective study of 5 patients who presented with preaxial polydactyly with hallux varus deformity, and were treated between 2003 and 2010 at the authors' hospital. Surgeries including extra digit excision, local flap, osteotomy, and interphalangeal joint fusion were performed taking into consideration the deformity types and patient's age. Family history, associated disease, and types of duplication were assessed, and the outcomes of surgery were evaluated with radiographs and appearances of foot. The mean follow-up period was 34 months. RESULTS: All 5 patients had one or more associated anomalies such as congenital anterolateral tibial bowing and polydactyly in three, translocation of chromosome 2 : 13 associated with cryptorchidism in one, pes planovalgus in one, residual poliomyelitis in one, syndactyly of the foot in two, and leg length discrepancy in one patient. There was no family history of hallux polydactyly in any of the cases. All five patients had duplication of the distal phalanx and one of them had a blocked proximal phalanx. The extra digit was completely removed and the varus deformity was corrected in all cases. CONCLUSION: There was a high incidence of associated diseases in patients with hallux polydactyly and varus deformity. Deformity correction could be obtained by surgeries chosen according to the individual deformity type and patient age.

Advances in molecular genetics research of IgA nephropathy / 中南大学学报(医学版)

Immunoglobulin A nephropathy (IgAN), which can develop into end-stage renal disease, is the most common primary glomerulonephritis. The pathogenesis of IgAN is not clear. Many studies have confirmed that genetic susceptibility is associated with IgAN, and it belongs to polygenic disease. Some studies have found that IgAN is associated with chromosome 6q22-23, 2q36 by linkage analysis, and several candidate genes have been confirmed to be associated with IgAN, such as angiotensin converting enzyme, Fc fragment of IgA receptor, human leukocyte antigen. In recent years, as the progression of molecular genetics and the Human Genome Project, more attention has been paid to the role of genetic factors in the pathogenesis of IgAN.

A Case of Partial Trisomy 2p23-pter Syndrome with Trisomy 18p Due to a de novo Supernumerary Marker Chromosome / 대한진단검사의학회지

Partial trisomy 2p is a rare but relatively well-defined syndrome with distinctive clinical features, including marked psychomotor delay, dysmorphic face, and congenital heart disease. The phenotype of trisomy 18p is variable, from normal appearance to moderate mental retardation. Most cases of trisomy 2p and trisomy 18p result from the inheritance of an unbalanced segregant from a balanced parental translocation or due to de novo duplication. Here, we present the first report of a combined partial trisomy 2p and trisomy 18p due to a supernumerary marker chromosome (SMC). The final karyotype of the patient was 47,XX,+der(18)t(2;18)(p23.1;q11.1)[22]/46,XX[8]. The patient had typical dysmorphic features of partial trisomy 2p23-pter syndrome and congenital heart disease. SMCs are remarkably variable in euchromatic DNA content and mosaicism level. The precise identification of the origin and composition of SMCs is essential for genotype-phenotype correlation and genetic counseling.