Clinical and genetic analysis of a child with maternal uniparental disomy of chromosome 20 / 中华医学遗传学杂志

OBJECTIVE@#To explore the clinical and genetic characteristics of a boy with isolated maternal uniparental disomy of chromosome 20 [UPD(20)mat].@*METHODS@#A child who was admitted to the Tongji Hospital Affiliated to Tongji Medical College of Huazhong University of Science and Technology on April 8,2021. was selected as the study subject. Phenotypic and endocrinological findings of the child were retrospectively analyzed. Whole exome sequencing (WES) and methylation-specific multiplex ligation-dependent probe amplification (MS-MLPA) were carried out for detecting the UPD sequences and copy number variations. Both of his parents were verified by Sanger sequencing. Relevant literature was systematically reviewed.@*RESULTS@#The child, a 3-year-and-8-month-old boy born to a 41-year-old mother by Cesarean delivery at 36+2 gestational weeks due to oligohydramia, had a birth weight of 2 300 g and length of 46 cm. He was admitted to the NICU for feeding difficulties which had persisted despite of clinical management. At the age of 3.75, he had a height of 92.5 cm (< 3rd percentile; 25th ~ 50th percentile at 2.5 years) and a weight of 10.8 kg (< 3rd percentile; 50th percentile at 15 months). He had also presented with growth retardation, short stature, attention deficit and hyperactivity disorder (ADHD), mild mental retardation, and speech and language development disorders. He had simian creases in both hands but no additional dysmorphic signs, and his motor development was normal. Serum insulin, thyroid-stimulating hormone, and insulin growth factor binding protein 3 levels were within the normal ranges, though insulin growth factor-1 (IGF-1) was slightly decreased. Since that time he had continuously used atomoxetine hydrochloride capsules to control his ADHD. WES and MS-MLPA revealed the existence of UPD (20)mat.@*CONCLUSION@#The UPD(20)mat syndrome is characterized by feeding difficulties, growth retardation and short stature. The child in our case has been accompanied by ADHD and speech and language development disorders, which required long-term treatment. For women with advanced maternal age and suggestive phenotypes, genetic testing and counseling should be conducted.

Genetic Architecture of Circulating Very-Long-Chain (C24:0 and C22:0) Ceramide Concentrations

OBJECTIVE: Total ceramide concentrations are linked with increased insulin resistance and cardiac dysfunction. However, recent studies have demonstrated that plasma concentrations of specific very-long-chain fatty ceramides (C24:0 and C22:0) are associated with a reduced incidence of coronary heart disease and all-cause mortality. We hypothesized that specific genetic loci are associated with plasma C22:0 and C24:0 concentrations.METHODS: Heritability and genome-wide association studies of plasma C24:0 and C22:0 ceramide concentrations were performed among 2,217 participants in the Framingham Heart Study Offspring Cohort, adjusting for cardiovascular risk factor covariates and cardiovascular drug treatment.RESULTS: The multivariable-adjusted heritability for C22:0 and C24:0 ceramides was 0.42 (standard error [SE], 0.07; p=1.8E-9) and 0.25 (SE, 0.08; p=0.00025), respectively. Nineteen single nucleotide polymorphisms (SNPs), all on chromosome 20, significantly associated with C22:0 concentrations; the closest gene to these variants was SPTLC3. The lead SNP (rs4814175) significantly associated with 3% lower plasma C22:0 concentrations (p=2.83E-11). Nine SNPs, all on chromosome 20 and close to SPTLC3, were significantly associated with C24:0 ceramide concentrations. All 9 were also significantly related to plasma C22:0 levels. The lead SNP (rs168622) was significantly associated with 10% lower plasma C24:0 ceramide concentrations (p=9.94E-09).CONCLUSION: SNPs near the SPTLC3 gene, which encodes serine palmitoyltransferase long chain base subunit 3 (SPTLC3; part of the enzyme that catalyzes the rate-limiting step of de novo sphingolipid synthesis) were associated with plasma C22:0 and C24:0 ceramide concentrations. These results are biologically plausible and suggest that SPTLC3 may be a potential therapeutic target for C24:0 and C22:0 ceramide modulation.

Pseudohypoparathyroidism type 1b due to paternal uniparental disomy of chromosome 20q: A case report

Pseudohypoparathyroidism type 1b (PHP 1b) is the result of end organ resistance to parathyroid hormone (PTH) in the absence of any features of Albright's hereditary osteodystrophy. There are two subtypes of PHP 1b with different genetic mechanisms. One subtype is related to a maternally derived 3kb microdeletion involving STX 16 gene, and is inherited in an autosomal dominant mode. Familial autosomal dominant inheritance of PHP 1b is relatively rare. The other subtype is associated with more extensive loss of imprinting at the GNAS locus that affects at least one additional differential methylated (hypermethylation at neuroendocrine secretory protein and hypomethylation at antisense transcript and or extra-large stimulatory G protein region) without microdeletion of the STX 16 or AS gene. It can be sporadic due to an imprinting defect in the GNAS gene. In our case, an 8-year-old girl was referred for suspected PHP with no feature of Albright hereditary osteodystrophy. Blood test results revealed hypocalcemia and hyperphosphatemia. Elevated PTH was also checked. There was no family history of endocrine or developmental problem. Her intelligence was normal, but she had inferior sociability at that time. Based on above, we diagnosed a rare case of paternal uniparental disomy of the long arm of chromosome 20 as the cause of PHP 1b by microsatellite marker test of chromosome 20.

A case of maternal uniparental disomy of chromosome 20 detected by noninvasive prenatal test of 1,000 high-risk pregnancies

Chromosomal loss in trisomy (trisomy rescue) to generate a disomic fetus can cause confined placental mosaicism and/or feto/placental mosaicism. After trisomy rescue event, there is a risk of fetal uniparental disomy (UPD). Noninvasive prenatal test (NIPT) reflects the genomic constitution of the placenta, not of the fetus itself. Feto-placental discrepancy can therefore cause false-positive (trisomy) NIPT results. These discordant NIPT results can serve as important clues to find UPD associated with confined placental mosaicism. We report a case with maternal UPD of chromosome 20, detected by NIPT of 1,000 high-risk pregnancies, carried out for detecting chromosomal abnormalities in Koreans.

Association of eight single nucleotide polymorphisms of chromosomes 20 and X with androgenetic alopecia among ethnic Han Chinese from Yunnan / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To assess the association of 8 single nucleotide polymorphisms (SNPs) from chromosomes X and 20 with androgenetic alopecia among ethnic Han population from Yunnan province.</p><p><b>METHODS</b>An eight-SNP co-amplification protocol was developed for the genotyping with a SNaPshot platform. A case-control study was carried out for the 8 SNPs from chromosomes X and 20 in 115 androgenetic alopecia cases and 125 healthy controls. Statistical analysis was conducted with SPSS17.0, Haploview4.2, SHEsis and MDR software.</p><p><b>RESULTS</b>No association was found between the two groups with regard to the 4 SNPs located on the X chromosome. The genotypic frequencies of rs2180439, rs913063 and rs1160312 were significantly different between the two groups (P < 0.05). The frequency of T allele of rs2180439 was significantly higher in the case group (P < 0.05). The frequencies of A alleles of rs913063 and rs1160312 were significantly higher in the case group (P < 0.05). The haplotypes of C-T-C-G, T-C-C-G and T-T-A-A based on rs6137444-rs2180439-rs913063-rs1160312 showed significant difference between the two groups (P <0.05). rs6137444, rs21804393 and rs1160312 have a strong association with androgenetic alopecia.</p><p><b>CONCLUSION</b>The 4 SNPs located on chromosome X were all monomorphic among ethnic Hans from Yunnan. The rs6152, rs16990427, rs1352015, rs1385699 SNPs located on chromosome 20 are associated with androgenetic alopecia in the same population. Individuals with T allele of rs2180439 and A allele of rs913063 and rs1160312 are more likely to develop androgenetic alopecia.</p>

Recent advances in clinical and genetic research of spinocerebellar ataxia type 36 / 中华医学遗传学杂志

Non-coding expansion spinocerebellar ataxias (SCAs) are a group of autosomal dominant neurodegenerative diseases characterized by "CTA/CTG", "ATTCT", "TGGAA" expansion in non-coding region of the causative gene. Until now, 5 subtypes including SCA8, SCA10, SCA12, SCA31 and SCA36 have been mapped. Recently, the causative mutation for SCA36, namely intronic hexanucleotide GGCCTG expansion in NOP56 gene, has been identified in Japanese and Spanish pedigrees in succession. Compared with other subtypes of SCAs, there are certain distinctive characteristics for SCA36. The clinical and genetic features of SCA36 are reviewed in this paper.

Clinical and cytogenetic study of 6 cases of hematological disorders associated with 20q- and t (20;21) (q11;q11) abnormalities / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To analyze clinical and cytogenetic features of hematological disorders associated with 20q- and t (20;21) (q11;q11) abnormalities.</p><p><b>METHODS</b>Following short-term culture of bone marrow cells, karyotypic analysis was carried out with R-banding. 20q- and t(20;21) (q11;q11) was detected by fluorescence in situ hybridization (FISH) using dual-color 20q11/12 probe, ST 20qter /ST 21qter probes, SE20(D20Z1)/SE 13/21 probes, and WC20/WC21 probes.</p><p><b>RESULTS</b>Six (2.3%) of the 257 patients with 20q- detected by conventional karyotypic analysis were found to have t(20;21) (q11;q11) abnormality. Five cases had myelodysplastic syndrome, 1 had acute lymphoblastic leukemia. Above results were all confirmed by FISH.</p><p><b>CONCLUSION</b>i (20q-), t(20;21) (q11;q11) seems to be a rare but recurrent chromosomal abnormality which is specifically associated with myeloid disease, late occurrence and poor prognosis. The translocation between chromosome 20q11 and 21q11 may form a novel fusion gene which has an important role in the pathogenesis of the disease.</p>

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.

Isolated deletion of the long arm of chromosome 20 del(20q12) in myelodysplastic syndrome: a case report and literature review

Isolated deletion of the long arm of chromosome 20 [del(20q12)] is a rare abnormality in patients with de novo myelodysplastic syndrome. It is characterised by refractory thrombocytopenia, minimal haematological dysplasia and a lower risk for progression to acute myeloid leukaemia. Its distinction from chronic autoimmune thrombocytopenia, although clinically and morphologically difficult, is critical. We report a case of refractory cytopenia and unilineage dysplasia in an elderly woman with isolated del(20q12), identified via fluorescence in situ hybridisation analysis of her bone marrow. In order to avoid a misdiagnosis, we suggest that cytogenetic analysis be performed on all patients suspected to have myelodysplastic syndrome with predominant thrombocytopenic presentation.

A Case of Partial Trisomy 20p Resulting from Meiotic Recombination of a Maternal Pericentric Inversion

Here we report the cytogenetic and clinical manifestations observed in a patient with a rec(20)dup(20p)inv(20)(p11.2q13.3)mat. The patient was a full-term newborn girl with asymmetric intrauterine growth restriction and multiple congenital malformations, including a ventricular septal defect, pulmonary atresia, ambiguous genitalia, clinodactyly, and sacral dimpling. To our knowledge, this is the 4th report in the world and the 1st one in Korea of a patient with rec(20)dup(20p).

An unrelated Clone of 20q Deletion Following Successful Treatment of Leukemia in Patients with t(8;21), t(15;17) or t(9;22) / 임상검사와정도관리

Cases of clonal cytogenetic abnormalities in Philadelphia-negative cells during the treatment of Philadelphia-positive CML have been previously reported. However, clonal abnormalities unrelated to the original t(8;21) or t(15;17) karyotype are not common. Deletion of 20q (del(20q)) is one of the most common recurrent cytogenetic abnormalities in myeloid neoplasms. Here we describe 3 patients with t(8;21), t(15;17), or t(9;22) who developed unrelated del(20q) after successful treatment of leukemia. We retrospectively reviewed the cytogenetic results of 23 AML patients with t(8;21)(q22;q22), 28 AML patients with t(15;17)(q22;q12), and 47 CML patients with t(9;22)(q34;q11.2). We identified 3 patients with del(20q) as the only clonal aberration unrelated to the primary karyotype when they achieved complete morphologic and cytogenetic remission. The latency period between diagnosis and emergence of del(20q) was 1, 114, and 35 months for the 3 patients, respectively. There was no evidence of therapy-related MDS/AML during the follow-up period. In 1 AML patient with t(8;21), relapse occurred in a t(8;21)(q22;q22) clone and the del(20q) clones were lost. The clinical significance of del(20q) as an unrelated clonal aberration is unknown, but our study suggests that del(20q) does not cause therapy-related MDS/AML or indicate disease progression.

Report of ten cases of hematologic malignancies with idic(20q-) and literature review / 中华血液学杂志

<p><b>OBJECTIVE</b>To analyze the clinical and molecular cytogenetic features of hematologic malignancies with idic(20q-).</p><p><b>METHODS</b>The clinical data of 10 patients with idic (20q-) were analyzed. Karyotyping analysis was carried out with R banding technique. A CEP20 probe was used to perform single-color fluorescence in situ hybridization (FISH). A subtelomeric probe for 20q and a locus-specific probe for 20q12 were used to perform dual-color FISH. The literatures of hematologic malignancies with idic(20q-) were reviewed.</p><p><b>RESULTS</b>Of the 10 cases, 2 were diagnosed as acute erythroid leukemia, 1 primary myelofibrosis, 3 myelodysplastic syndromes (MDS) and 4 highly suspected (HS-MDS). Karyotype analysis showed that one of the normal chromosome 20 allele was substituted by one or two metacentric isochromosomes smaller than the normal one in all 10 cases. It was confirmed to be der(20)del(20)(q11q13)idic(20)(p11), i.e., idic(20q-) by FISH assay. Partial cells in 2 of the 10 cases had 20q- as the sole karyotypic anomaly.</p><p><b>CONCLUSION</b>Idic(20q-) results from a pre-existing del(20q) and is strongly associated with MDS and acute erythroid leukemia. Idic(20q-) as a recurrent cytogenetic abnormality is helpful for diagnosing HS-MDS in patients with cytopenia but only slight or absent dysplasia.</p>

Linkage of three polymorphisms on chromosome 20p12 to ossification of the posterior longitudinal ligament of spine and its severity in Han Chinese patients / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Ossification of the posterior longitudinal ligament (OPLL) is characterized by the replacement of ligamentous tissue with new ectopic bone formation, and has a strong genetic background. Because of the abnormal bone metabolic features and the strong genetic component, osteoporosis is a related disorder with OPLL. Three polymorphisms on chromosome 20p12 were identified associated with the risk of osteoporosis and osteoporotic fracture. The rs996544 (C/T) "TT" and rs965291 (G/A) "AA" genotypes conferred higher risks for vertebral and hip fractures. The osteoporosis haplotype is defined by two polymorphisms, rs1116867 (A) and D35548 (T). However, it remains unknown whether these three polymorphisms predispose to an increased frequency and severity of OPLL in Han Chinese patients.</p><p><b>METHODS</b>A total of 420 OPLL patients and 506 age- and sex-matched controls were studied. Three single nucleotide polymorphisms (SNPs), rs996544 (C/T), rs965291 (G/A) and rs1116867 (A/G), were analyzed by direct sequencing. Associations between these SNPs with the occurrence and extent of OPLL were statistically evaluated.</p><p><b>RESULTS</b>There was no significant association between the rs996544 (C/T) polymorphism and the prevalence of OPLL. The rs1116867 (A/G) polymorphism "AG" genotype was associated with the occurrence of OPLL. The rs1116867 (A/G) polymorphism "G" allele was associated with the occurrence of OPLL, but not with the extent of OPLL. The rs965291 (G/A) polymorphism in female patients was statistically different between cases and controls (P < 0.05). The rs965291 (G/A) polymorphism "A" allele was associated with the occurrence of OPLL in female patients. For the rs965291 (G/A) polymorphism, patients with the "A" allele (genotype, "AG" or "AA") showed a significantly greater number of ossified cervical vertebrae than those without the "A" allele (genotype, "GG", P < 0.05), particularly in female patients.</p><p><b>CONCLUSIONS</b>The rs1116867 (A/G) and rs965291 (G/A) polymorphisms on chromosome 20p12 are associated with the occurrence and the extent of OPLL, at least in Han Chinese subjects. Our data should advance our understanding of the molecular etiology of OPLL and may guide approaches to prevent the onset of OPLL.</p>

A Cytogenetic Analysis of Abortus with Spontaneous Abortion

PURPOSE: Chromosomal abnormalities of abortuses have been used to investigate common etiologies of spontaneous abortion, but the frequencies and types of spontaneous abortions have demonstrated considerable variation among different countries and races. MATERIALS AND METHODS: A cytogenetic analysis of 75 abortuses was performed at GenDix, Inc. from January 2006 to December 2007. RESULTS: The frequency of chromosome abnormalities in abortuses was 32.0% (24/75 cases). Among the chromosomal abnormalities, trisomy was present in 62.5% (15/24 cases) of cases and the most frequent trisomy was trisomy 21 with an occurrence rate of 26.6% (4/15 cases). The following was trisomy 22 (3/15 cases) and trisomy 20 (2/15 cases). The average maternal age for abnormal karyotypes was 34.3+/-3.3. CONCLUSION: Cytogenetic analysis of abortus is important for diagnosis and genetic counseling of patients with spontaneous abortion.

Prenatally Diagnosed Uncommon Mosaic Autosomal Trisomy

Prenatal diagnosis of rare autosome mosaicism involvingchromosomes other than chromosome 13, 18, 21 or the sex chromosome is encountered prognostic dilemma during genetic counseling. We report four cases of level III uncommon mosaicism of trisomy 5, 16 and 20,diagnosed prenatally. In case 1 with mosaic trisomy 20, there was a higher mosaic ratio of trisomy 20 in the repeat amniocentesis (62.1%) than in the first (36.6%) with normal fetal ultrasound finding except for a relatively small aorta on a 3-vessel view of the fetal heart. Case 2 showed a low rate of mosaic trisomy 20 (5.25%) in cultured amniocytes but normal karyotype in the repeat amniocentesis, who delivered a normal healthy baby. Case 3 showed a 13.6% of trisomy 16 mosaicism in the 30 cells of cultured amniocytes. Sixty cells from a fetal blood sample at termination showed non-mosaic 46,XX normal karyotype, while skin fibroblasts had 22.5% trisomy 16 in 40 metaphases. The autopsy showed ventricular septal defect (VSD). Case 4 with low grade mosaicism (10.5%) of trisomy 5 resulted in elective termination, though the ultrasoumd showed growsly normal fetus. Although level III mosaicism is regarded as true mosaicism, it is difficult to predict the outcome of the fetus with rare mosaic autosome trisomy. Therefore mosaic autosome trisomy of fetus should be carefully interpreted with more various approaches including repeat sampling and targeted fetal ultrasound.

Discrepancy in cytogenetic results between amniotic fluid cells and other fetal tissues: A case report / 대한산부인과학회지

We present two fetuses who were prenatally diagnosed by amniocentesis as having chromosomal mosaicism but who had a normal karyotype in the fetal blood by cordocentesis. One of the both fetuses had Turner and the other had trisomy 20 mosaicism. The prognosis for Turner mosaicism and trisomy 20 mosaicism diagnosed prenatally has yet to be established. The pregnancy with 45,X/46,XX mosaicism was terminated at 23+3 weeks' gestation. Autopsy findings showed no features of Turner's syndrome. Postnatal cytogenetic analysis revealed 45,X[4]/46,XX[52] mosaicism in skin and 46,XX in the lung tissue. The other fetus had amniocytes with trisomy 20 mosaicism and fetal cord blood cells with a normal karyotype. The baby was delivered at 38+2 weeks' gestation. At birth and 3 months after birth, no apparent abnormal findings were found. These cases with chromosomal discrepancy among various fetal tissues are rare. Two cases were discussed with the review of literature.

Distribution of abnormal cell clone with deletion of chromosome 20q in marrow cell lineages and apoptosis cells in myelodysplastic syndrome / 中国实验血液学杂志

This study was aimed to investigate the distribution of abnormal clone in marrow cell lineages and apoptosis cells in myelodysplastic syndrome (MDS) with deletion of chromosome 20q. Monoclonal antibodies recognizing myeloid precursors (CD15), erythroid precursors (GPA), T cells (CD3(+)CD56(-)CD16(-)), B cells (CD19), NK cells (CD3(-)CD56(+)CD16(+)) were used to sort bone marrow cells in a MDS patient with del (20q) by fluorescence activated cell sorting (FACS). Annexin V-FITC and PI were used to sort bone marrow Annexin V(+)PI(-) and Annexin V(-)PI(-) cells by FACS. The sorted positive cells were detected by interphase dual-color fluorescence in situ hybridization (D-FISH) using a LSI D20S108 probe (Spectrum Orange) and a Telvysion TM 20p probe (Spectrum Green). FACS and FISH analysis were also performed on the samples from 4 cases with normal karyotype. The results showed that the proportions of MDS clone in the myeloid and erythroid precursors were 70.50% and 93.33% respectively, in the RAEB-1 patient with del (20q) and were obviously higher than that in control group (5.39% and 6.17%). The proportions of abnormal clone in T, B and NK cells were 3.23%, 4.32% and 5.77% respectively and were less than that in control group (5.76%, 4.85%, 6.36%). The percentage of apoptotic cells in the bone marrow nucleated cells was 16.09%. The proportions of MDS clone in Annexin V(+)PI(-) and Annexin V(-)PI(-) cells were 32.48% and 70.11%, respectively. It is concluded that most myeloid and erythroid precursors are originated from the abnormal clone in MDS with del (20q). A little part of apoptotic cells are derived from the abnormal clone.

A locus on chromosome 20 encompassing genes that are highly expressed in the epididymis / 亚洲男科学杂志(英文版)

During liquefaction of the ejaculate, the semen coagulum proteins semenogelin I (SEMG1) and semenogelin II (SEMG2) are degraded to low molecular mass fragments by kallikrein-related peptidase 3 (KLK3), also known as prostate-specific antigen. Semenogelin molecules initiate their own destruction by chelating Zn(2+) that normally would completely inhibit the proteolytic activity of KLK3. In a similar way, semenogelins might regulate the activity of kallikrein-related peptidases in the epididymis, something that might be of importance for the maturation of spermatozoa or generation of anti-bacterial peptides. Studies on the evolution of semen coagulum proteins have revealed that most of them carry an exon that displays a rapid and unusual evolution. As a consequence, homologous proteins in rodents and primates show almost no conservation in primary structure. Further studies on their evolution suggest that the progenitor of the semen coagulum proteins probably was a protease inhibitor that might have displayed antimicrobial activity. The semenogelin locus on chromosome 20 contains at least 17 homologous genes encoding probable protease inhibitors with homology to semen coagulum proteins. All of these are highly expressed in the epididymis where they, similar to the semenogelins, could affect the maturation of spermatozoa or display antibacterial properties.

Genetic Alterations in Primary Gastric Carcinomas Correlated with Clinicopathological Variables by Array Comparative Genomic Hybridization

Genetic alterations have been recognized as an important event in the carcinogenesis of gastric cancer (GC). We conducted high resolution bacterial artificial chromosome array-comparative genomic hybridization, to elucidate in more detail the genomic alterations, and to establish a pattern of DNA copy number changes with distinct clinical variables in GC. Our results showed some correlations between novel amplified or deleted regions and clinical status. Copy-number gains were frequently detected at 1p, 5p, 7q, 8q, 11p, 16p, 20p and 20q, and losses at 1p, 2q, 4q, 5q, 7q, 9p, 14q, and 18q. Losses at 4q23, 9p23, 14q31.1, or 18q21.1 as well as a gain at 20q12 were correlated with tumor-node-metastasis tumor stage. Losses at 9p23 or 14q31.1 were associated with lymph node status. Metastasis was determined to be related to losses at 4q23 or 4q28.2, as well as losses at 4q15.2, 4q21.21, 4q 28.2, or 14q31.1, with differentiation. One of the notable aspects of this study was that the losses at 4q or 14q could be employed in the evaluation of the metastatic status of GC. Our results should provide a potential resource for the molecular cytogenetic events in GC, and should also provide clues in the hunt for genes associated with GC.

Clinical and laboratory characteristics of two acute lymphoblastic leukemia patients with dicentric (9; 20) (p11 - 13; q11) / 中华血液学杂志

<p><b>OBJECTIVE</b>To explore the morphologic, immunophenotypic, cytogenetic and clinical features of acute lymphoblastic leukemia (ALL) patients with dicentric (9; 20) (p11 - 13; q11).</p><p><b>METHODS</b>Chromosome specimens of bone marrow cells were prepared by direct method and/or short-time culture. Karyo-typing was performed by R-banding technique. Dual-color fluorescence in situ hybridization (FISH) was performed using both chromosome 9 classical satellite probe and chromosome 20 alpha-satellite probe in one patient.</p><p><b>RESULTS</b>The two ALL patients were positive for CD10 and HLA-DR, showing of B cell origin. Both patients had dicentric (9; 20): case 1 was 45, XY, der (9) t (9; 20) (p11; q11), -20[20]; case 2 was 45, XX, der (9) t (9; 20) (p13; q11), t (9; 22) (q34; q11), -20[10]/46, idem, +8[16]/47, idem, +8, +21[14]. Mutual translocation between chromosomes 9 and 20 of the dicentric chromosome was confirmed by FISH in one patient.</p><p><b>CONCLUSIONS</b>Dicentric (9; 20) (p11 - 13; q11) is a rare recurring chromosome abnormality associated with ALL. Because of the subtle nature of the translocation, FISH is essential for the detection of this abnormality.</p>