Methylenetetrahydrofolate Reductase Dimer Configuration as a Risk Factor for Maternal Meiosis I-Derived Trisomy 21

2021 ◽  
pp. 1-5
Author(s):  
Jadranka Vraneković ◽  
Ivana Babić Božović ◽  
Iva Bilić Čače ◽  
Bojana Brajenović Milić
Keyword(s):  
Trisomy 21 ◽  
Methylenetetrahydrofolate Reductase ◽  
Chromosome 21 ◽  
Parental Origin ◽  
Folic Acid Supplements ◽  
Pcr Rflp ◽  
Meiotic Nondisjunction ◽  
Study Participants ◽  
Short Tandem Repeat Markers ◽  
Meiosis I

<b><i>Background:</i></b> Evidence suggests that the dimer configuration of methylenetetrahydrofolate reductase (MTHFR) enzyme might be destabilized by polymorphisms in monomers at the positions C677T and A1298C. It has been observed that these polymorphisms may lead to stable (CCAA, CCAC, CCCC) and unstable (CTAA, CTAC, TTAA) enzyme dimer configurations. <b><i>Objective:</i></b> The aim of this study was to evaluate the association of the MTHFR enzyme dimer configuration and folate dietary intake with the stage of meiotic nondisjunction in mothers of children with maternally derived trisomy 21. <b><i>Methods:</i></b> A total of 119 mothers of children with maternally derived free trisomy 21 were included in the study. The mean maternal age at the time of the birth of the child with trisomy 21 was 32.3 ± 6.4 (range 16–43) years. All mothers were Caucasian. Parental origin of trisomy 21 and meiotic stage of nondisjunction was determined using short tandem repeat markers spanning from the centromere to the telomere of chromosome 21q. The <i>MTHFR</i> C677T and <i>A1298C</i> polymorphism was evaluated by PCR-RFLP. <b><i>Results:</i></b> Increased frequency of the <i>MTHFR</i> genotype combinations CTAA, CTAC, and TTAA was found in the group of mothers with meiosis I (MI) nondisjunction (<i>p</i> = 0.007). No differences were found between study participants regarding dietary and lifestyles habits. <b><i>Conclusion:</i></b> The risk for MI nondisjunction of chromosome 21 was 4.6-fold higher in cases who had CTAA, CTAC, and TTAA <i>MTHFR</i> genotype combinations and who did not used folic acid supplements in the preconception period.

scholarly journals What Causes Down Syndrome?

2021 ◽  
Author(s):  
Emine Ikbal Atli
Keyword(s):  
Risk Factors ◽  
Down Syndrome ◽  
Trisomy 21 ◽  
Maternal Age ◽  
Extra Chromosome ◽  
Advanced Maternal Age ◽  
Chromosome 21 ◽  
Human Phenotype ◽  
Meiosis I ◽  
Dosage Imbalance

Trisomy 21 (Down Syndrome) is the model human phenotype for all genome gain-dosage imbalance situations, including microduplications. Years after the sequencing of chromosome 21, the discovery of functional genomics and the creation of multiple cellular and mouse models provided an unprecedented opportunity to demonstrate the molecular consequences of genome dosage imbalance. It was stated years ago that Down syndrome, caused by meiotic separation of chromosome 21 in humans, is associated with advanced maternal age, but defining and understanding other risk factors is insufficient. Commonly referred to as Down syndrome (DS) in humans, trisomy 21 is the most cited genetic cause of mental retardation. In about 95% of cases, the extra chromosome occurs as a result of meiotic non- nondisjunction (NDJ) or abnormal separation of chromosomes. In most of these cases the error occurs during maternal oogenesis, especially in meiosis I.

scholarly journals Molecular Analysis of Nondisjunction in Mice Heterozygous for a Robertsonian Translocation

Genetics ◽  
2002 ◽  
Vol 161 (3) ◽  
pp. 1219-1224
Author(s):  
Lara A Underkoffler ◽  
Laura E Mitchell ◽  
A Russell Localio ◽  
Shannon M Marchegiani ◽  
Justin Morabito ◽  
...  
Keyword(s):  
Molecular Analysis ◽  
Robertsonian Translocation ◽  
Metacentric Chromosome ◽  
Paternal Age ◽  
Chromosome 7 ◽  
Parental Origin ◽  
Molecular Genotyping ◽  
Factors Influencing ◽  
Meiotic Nondisjunction ◽  
Acrocentric Chromosomes

Abstract A Robertsonian translocation results in a metacentric chromosome produced by the fusion of two acrocentric chromosomes. Rb heterozygous mice frequently generate aneuploid gametes and embryos, providing a good model for studying meiotic nondisjunction. We intercrossed mice heterozygous for a (7.18) Robertsonian translocation and performed molecular genotyping of 1812 embryos from 364 litters with known parental origin, strain, and age. Nondisjunction events were scored and factors influencing the frequency of nondisjunction involving chromosomes 7 and 18 were examined. We concluded the following: The frequency of nondisjunction among 1784 embryos (3568 meioses) was 15.9%.Nondisjunction events were distributed nonrandomly among progeny. This was inferred from the distribution of the frequency of trisomics and uniparental disomics (UPDs) among all litters.There was no evidence to show an effect of maternal or paternal age on the frequency of nondisjunction.Strain background did not play an appreciable role in nondisjunction frequency.The frequency of nondisjunction for chromosome 18 was significantly higher than that for chromosome 7 in males.The frequency of nondisjunction for chromosome 7 was significantly higher in females than in males. These results show that molecular genotyping provides a valuable tool for understanding factors influencing meiotic nondisjunction in mammals.

scholarly journals Double or nothing: a Drosophila mutation affecting meiotic chromosome segregation in both females and males.

Genetics ◽  
1994 ◽  
Vol 136 (3) ◽  
pp. 953-964 ◽  
Author(s):  
D P Moore ◽  
W Y Miyazaki ◽  
J E Tomkiel ◽  
T L Orr-Weaver
Keyword(s):  
Cell Death ◽  
Chromosome Segregation ◽  
Sister Chromatid ◽  
Meiotic Chromosome ◽  
Sister Chromatid Cohesion ◽  
Aberrant Chromosome ◽  
Chromatid Cohesion ◽  
Meiotic Nondisjunction ◽  
Lethal Allele ◽  
Meiosis I

Abstract We describe a Drosophila mutation, Double or nothing (Dub), that causes meiotic nondisjunction in a conditional, dominant manner. Previously isolated mutations in Drosophila specifically affect meiosis either in females or males, with the exception of the mei-S332 and ord genes which are required for proper sister-chromatid cohesion. Dub is unusual in that it causes aberrant chromosome segregation almost exclusively in meiosis I in both sexes. In Dub mutant females both nonexchange and exchange chromosomes undergo nondisjunction, but the effect of Dub on nonexchange chromosomes is more pronounced. Dub reduces recombination levels slightly. Multiple nondisjoined chromosomes frequently cosegregate to the same pole. Dub results in nondisjunction of all chromosomes in meiosis I of males, although the levels are lower than in females. When homozygous, Dub is a conditional lethal allele and exhibits phenotypes consistent with cell death.

RUNX1 DNA-binding mutations and RUNX1-PRDM16 cryptic fusions in BCR-ABL+ leukemias are frequently associated with secondary trisomy 21 and may contribute to clonal evolution and imatinib resistance

Blood ◽  
2008 ◽  
Vol 111 (7) ◽  
pp. 3735-3741 ◽  
Author(s):  
Catherine Roche-Lestienne ◽  
Lauréline Deluche ◽  
Sélim Corm ◽  
Isabelle Tigaud ◽  
Sami Joha ◽  
...  
Keyword(s):  
Dna Binding ◽  
High Frequency ◽  
Trisomy 21 ◽  
De Novo ◽  
Blast Crisis ◽  
Clonal Evolution ◽  
Chronic Phase ◽  
Chromosome 21 ◽  
Imatinib Resistance ◽  
Molecular Abnormalities

Abstract Acquired molecular abnormalities (mutations or chromosomal translocations) of the RUNX1 transcription factor gene are frequent in acute myeloblastic leukemias (AMLs) and in therapy-related myelodysplastic syndromes, but rarely in acute lymphoblastic leukemias (ALLs) and chronic myelogenous leukemias (CMLs). Among 18 BCR-ABL+ leukemias presenting acquired trisomy of chromosome 21, we report a high frequency (33%) of recurrent point mutations (4 in myeloid blast crisis [BC] CML and one in chronic phase CML) within the DNA-binding region of RUNX1. We did not found any mutation in de novo BCR-ABL+ ALLs or lymphoid BC CML. Emergence of the RUNX1 mutations was detected at diagnosis or before the acquisition of trisomy 21 during disease progression. In addition, we also report a high frequency of cryptic chromosomal RUNX1 translocation to a novel recently described gene partner, PRDM16 on chromosome 1p36, for 3 (21.4%) of 14 investigated patients: 2 myeloid BC CMLs and, for the first time, 1 therapy-related BCR-ABL+ ALL. Two patients presented both RUNX1 mutations and RUNX1-PRDM16 fusion. These events are associated with a short survival and support the concept of a cooperative effect of BCR-ABL with molecular RUNX1 abnormalities on the differentiation arrest phenotype observed during progression of CML and in BCR-ABL+ ALL.

scholarly journals Lack of evidence for association of meiotic nondisjunction with particular DNA haplotypes on chromosome 21.

1988 ◽  
Vol 85 (13) ◽  
pp. 4794-4798 ◽  
Author(s):  
N. Sacchi ◽  
J. F. Gusella ◽  
L. Perroni ◽  
F. D. Bricarelli ◽  
T. S. Papas
Keyword(s):  
Chromosome 21 ◽  
Meiotic Nondisjunction

Trisomy 21 and isodicentric chromosome 21 in Kostmann syndrome following treatment with G-CSF

2001 ◽  
Vol 126 (1) ◽  
pp. 78-80 ◽  
Author(s):  
Birgitte Roland ◽  
Richard C Woodman ◽  
Keith Jorgenson ◽  
Alfredo Pinto
Keyword(s):  
Trisomy 21 ◽  
Chromosome 21 ◽  
Kostmann Syndrome ◽  
Isodicentric Chromosome

Molecular Cytogenetic Classification of Down Syndrome and Screening of Somatic Aneuploidy in Mothers

2021 ◽  
pp. 1-9
Author(s):  
Sushil Kumar Jaiswal ◽  
Ashok Kumar ◽  
Amit Kumar Rai
Keyword(s):  
Down Syndrome ◽  
Peripheral Blood ◽  
Trisomy 21 ◽  
Health Management ◽  
Chromosome 21 ◽  
Robertsonian Translocations ◽  
Significant Difference ◽  
And Control

Down Syndrome (DS) caused by trisomy 21 results in various congenital and developmental complications in children. It is crucial to cytogenetically diagnose the DS cases early for their proper health management and to reduce the risk of further DS childbirths in mothers. In this study, we performed a cytogenetic analysis of 436 suspected DS cases using karyotyping and fluorescent in situ hybridization. We detected free trisomies (95.3%), robertsonian translocations (2.4%), isochromosomes (0.6%), and mosaics (1.2%). We observed a slightly higher incidence of DS childbirth in younger mothers compared to mothers with advanced age. We compared the somatic aneuploidy in peripheral blood of mothers having DS children (MDS) and control mothers (CM) to identify biomarkers for predicting the risk for DS childbirths. No significant difference was observed. After induced demethylation in peripheral blood cells, we did not observe a significant difference in the frequency of aneuploidy between MDS and CM. In conclusion, free trisomy 21 is the most common type of chromosomal abnormality in DS. A small number of DS cases have translocations and mosaicism of chromosome 21. Additionally, somatic aneuploidy in the peripheral blood from the mother is not an effective marker to predict DS childbirths.

Chromosome 21, Trisomy 21, and Alzheimer’s Disease

1988 ◽  
pp. 89-94
Author(s):  
P.-M. Sinet ◽  
Z. Rahmani ◽  
J.-L. Blouin ◽  
A. Nicole ◽  
I. Ceballos ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Trisomy 21 ◽  
Chromosome 21

scholarly journals Gambaran Erupsi Gigi Permanen pada Anak Sindrom Down Usia 10-16 Tahun di Sekolah Luar Biasa Kabupaten Jember

2018 ◽  
Vol 8 (1) ◽  
pp. 8
Author(s):  
Loly Anastasya Sinaga ◽  
Dwi Kartika Apriyono ◽  
Masniari Novita
Keyword(s):  
Down Syndrome ◽  
Special Needs ◽  
Physical Characteristic ◽  
Trisomy 21 ◽  
Genetic Disorder ◽  
Extra Chromosome ◽  
Descriptive Study ◽  
Chromosome 21 ◽  
Permanent Teeth ◽  
Intellectual Abilities

Background: Down Syndrome is a genetic disorder that occurs because of chromosome 21 has three chromosome (trisomy 21). The extra chromosome changes the genetic balance, physical characteristic, intellectual abilities, and physiological body function. Tooth eruption in Down Syndrome children typically delayed in both the timing and sequence of eruption up to two or three years. Objective: To observe the permanent teeth eruption in Down syndrome children at age 10-16 years old, boys and girls in Special Needs School in Jember. Materials and Methods: This research was a descriptive study with 7 subjects. Each subject was examined then calculated teeth that had emerged or functionally eruption with articualting paper. Result and Conclusion:  Both permanent teeth that is still partially erupted tooth (emerged/ EM) and had erupted perfectly (functionally eruption/ FE) delayed in eruption in Down Syndrome boys and girls at age 10-16 years old.

scholarly journals Nuchal translucency: an ultrasound marker for fetal chromosomal abnormalities

2001 ◽  
Vol 119 (1) ◽  
pp. 19-23 ◽  
Author(s):  
Gregório Lorenzo Acácio ◽  
Ricardo Barini ◽  
Walter Pinto Júnior ◽  
Renato Luís Silveira Ximenes ◽  
Heverton Pettersen ◽  
...  
Keyword(s):  
Diagnostic Test ◽  
Gestational Age ◽  
Trisomy 21 ◽  
Chromosomal Abnormalities ◽  
Screening Method ◽  
Nuchal Translucency ◽  
Chromosome 21 ◽  
Likelihood Ratios ◽  
South American Population ◽  
Population Type

CONTEXT: The literature shows an association between several ultrasound markers and chromosome abnormality. Among these, measurement of nuchal translucency has been indicated as a screening method for aneuploidy. The trisomy of chromosome 21 has been most evaluated. OBJECTIVE: To define the best fixed cutoff point for nuchal translucency, with the assistance of the ROC curve, and its accuracy in screening all fetal aneuploidy and trisomy 21 in a South American population. TYPE OF STUDY: Validation of a diagnostic test. SETTING: This study was carried out at the State University of Campinas, Campinas, Brazil. PARTICIPANTS: 230 patients examined by ultrasound at two tertiary-level private centers, at 10 to 14 weeks of gestation. DIAGNOSTIC TEST: The participants consisted of all those patients who had undergone ultrasound imaging at 10 to 14 weeks of gestation to measure nuchal translucency and who had had the fetal or neonatal karyotype identified. MAIN MEASUREMENTS: Maternal age, gestational age, nuchal translucency measurement, fetal or neonatal karyotype. RESULTS: Prevalence of chromosomal defects -- 10%; mean age -- 35.8 years; mean gestational age -- 12 weeks and 2 days; nuchal translucency (NT) thickness -- 2.18 mm. The best balance between sensitivity and specificity were values that were equal to or higher than 2.5 mm for overall chromosomal abnormalities as well as for the isolated trisomy 21. The sensitivity for overall chromosomal abnormalities and trisomy 21 were 69.5% and 75%, respectively, and the positive likelihood ratios were 5.5 and 5.0, respectively. CONCLUSION: The measurement of nuchal translucency was found to be fairly accurate as an ultrasound marker for fetal abnormalities and measurements equal to or higher than 2.5 mm were the best fixed cutoff points.

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