Trisomy 21 - Revision history

Z8600021 at 14:41, 24 August 2023

2023-08-24T14:41:07Z

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	{{#pmid:37600012}}		{{#pmid:37600012}}

			{{#pmid:37386331}}

	{{#pmid:29244163}}		{{#pmid:29244163}}

Z8600021 at 14:39, 24 August 2023

2023-08-24T14:39:57Z

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	===Reviews===		===Reviews===

			{{#pmid:37600012}}

	{{#pmid:29244163}}		{{#pmid:29244163}}

Z8600021 at 14:28, 24 August 2023

2023-08-24T14:28:42Z

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	===Reviews===		===Reviews===

	{{#pmid:29244163}}		{{#pmid:29244163}}

			{{#pmid:25412855}}

	{{#pmid:17048355}}		{{#pmid:17048355}}

Z8600021 at 01:57, 15 April 2020

2020-04-15T01:57:03Z

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	==History==		==History==
			{{Trisomy 21 Vignette}}
	[[File:John Langdon Down.jpg\|thumb\|John Langdon Down (1828 – 1896)]]		[[File:John Langdon Down.jpg\|thumb\|John Langdon Down (1828 – 1896)]]

Z8600021 at 12:19, 9 December 2019

2019-12-09T12:19:02Z

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	* '''aneuploidy''' - Term used to describe an abnormal number of chromosomes mainly (90%) due to chromosome malsegregation mechanisms in maternal meiosis I. (More? [[Prenatal Diagnosis]] \| [[Abnormal Development - Genetic]] \| [[Cell Division - Meiosis]])		* '''aneuploidy''' - Term used to describe an abnormal number of chromosomes mainly (90%) due to chromosome malsegregation mechanisms in maternal meiosis I. (More? [[Prenatal Diagnosis]] \| [[Abnormal Development - Genetic]] \| [[Cell Division - Meiosis]])

	* '''Down Syndrome''' - The historic name used for trisomy 21, named after the original identifier Down, J.L.H. in a 1866 paper (cited above).		* '''Down Syndrome''' - The historic name used for {{trisomy 21}}, named after the original identifier Down, J.L.H. in a 1866 paper (cited above).

	* '''karyotype''' - (Greek, ''karyon'' = kernel or nucleus + ''typos'' = stamp) Term used to describe the chromosomal (genetic) makeup (complement) of a cell. (More? [[Abnormal Development - Genetic]])		* '''karyotype''' - (Greek, ''karyon'' = kernel or nucleus + ''typos'' = stamp) Term used to describe the chromosomal (genetic) makeup (complement) of a cell. (More? [[Abnormal Development - Genetic]])

Z8600021 at 12:15, 9 December 2019

2019-12-09T12:15:51Z

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	* '''The Down Syndrome Association of Queensland'''P.O. Box 1293Milton Queensland 4064		* '''The Down Syndrome Association of Queensland'''P.O. Box 1293Milton Queensland 4064

	== Terms ==		==Terms==

	* '''alpha-fetoprotein''' - (AFP) A serum fetal glycoprotein produced by both the yolk sac and fetal liver. The presence of the protein in maternal blood is the basis of a test for genetic or developmental problems in the fetus. Low levels of AFP normally occur in the blood of a pregnant woman, high levels may indicate neural tube defects (spina bifida, anencephaly). (More? [[Alpha-Fetoprotein\|Alpha-Fetoprotein Test]])		* '''alpha-fetoprotein''' - (AFP) A serum fetal glycoprotein produced by both the yolk sac and fetal liver. The presence of the protein in maternal blood is the basis of a test for genetic or developmental problems in the fetus. Low levels of AFP normally occur in the blood of a pregnant woman, high levels may indicate neural tube defects (spina bifida, anencephaly). (More? [[Alpha-Fetoprotein\|Alpha-Fetoprotein Test]])
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	* '''triple markers''' - alpha-fetoprotein, human chorionic gonadotropin, and unconjugated estriol.		* '''triple markers''' - alpha-fetoprotein, human chorionic gonadotropin, and unconjugated estriol.

			{{Genetic Terms}}

	{{Glossary}}		{{Glossary}}

Z8600021 at 12:01, 9 December 2019

2019-12-09T12:01:54Z

← Older revision		Revision as of 23:01, 9 December 2019
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	== Terms ==		== Terms ==

	* '''alpha-fetoprotein''' - (AFP) A serum fetal glycoprotein produced by both the yolk sac and fetal liver. The presence of the protein in maternal blood is the basis of a test for genetic or developmental problems in the fetus. Low levels of AFP normally occur in the blood of a pregnant woman, high levels may indicate neural tube defects (spina bifida, anencephaly). (More? [[Alpha-Fetoprotein\|Alpha-Fetoprotein Test]])		* '''alpha-fetoprotein''' - (AFP) A serum fetal glycoprotein produced by both the yolk sac and fetal liver. The presence of the protein in maternal blood is the basis of a test for genetic or developmental problems in the fetus. Low levels of AFP normally occur in the blood of a pregnant woman, high levels may indicate neural tube defects (spina bifida, anencephaly). (More? [[Alpha-Fetoprotein\|Alpha-Fetoprotein Test]])

	* '''alpha-fetoprotein test''' (APF test) A prenatal test to measure the amount of a fetal protein in the mother's blood (or amniotic fluid). Abnormal amounts of the protein may indicate genetic or developmental problems in the fetus. Serum alpha-fetoprotein (AFP) is a fetal glycoprotein produced by the yolk sac and fetal liver. Low levels of AFP normally occur in the blood of a pregnant woman, high levels may indicate neural tube defects (spina bifida, anencephaly). (More? [[Alpha-Fetoprotein\|Alpha-Fetoprotein Test]])		* '''alpha-fetoprotein test''' (APF test) A prenatal test to measure the amount of a fetal protein in the mother's blood (or amniotic fluid). Abnormal amounts of the protein may indicate genetic or developmental problems in the fetus. Serum alpha-fetoprotein (AFP) is a fetal glycoprotein produced by the yolk sac and fetal liver. Low levels of AFP normally occur in the blood of a pregnant woman, high levels may indicate neural tube defects (spina bifida, anencephaly). (More? [[Alpha-Fetoprotein\|Alpha-Fetoprotein Test]])

	* '''aneuploidy''' - Term used to describe an abnormal number of chromosomes mainly (90%) due to chromosome malsegregation mechanisms in maternal meiosis I. (More? [[Prenatal Diagnosis]] \| [[Abnormal Development - Genetic]] \| [[Cell Division - Meiosis]])		* '''aneuploidy''' - Term used to describe an abnormal number of chromosomes mainly (90%) due to chromosome malsegregation mechanisms in maternal meiosis I. (More? [[Prenatal Diagnosis]] \| [[Abnormal Development - Genetic]] \| [[Cell Division - Meiosis]])

	* '''Down Syndrome''' - The historic name used for trisomy 21, named after the original identifier Down, J.L.H. in a 1866 paper (cited above).		* '''Down Syndrome''' - The historic name used for trisomy 21, named after the original identifier Down, J.L.H. in a 1866 paper (cited above).

	* '''karyotype''' - (Greek, ''karyon'' = kernel or nucleus + ''typos'' = stamp) Term used to describe the chromosomal (genetic) makeup (complement) of a cell. (More? [[Abnormal Development - Genetic]])		* '''karyotype''' - (Greek, ''karyon'' = kernel or nucleus + ''typos'' = stamp) Term used to describe the chromosomal (genetic) makeup (complement) of a cell. (More? [[Abnormal Development - Genetic]])

	* '''nuchal''' - neck, anatomically refers to the neck region.		* '''nuchal''' - neck, anatomically refers to the neck region.

	* '''nuchal translucency''' - (fetal nuchal-translucency thickness) An initial diagnostic ultrasound measurement in the fetal neck region carried out by trans-abdominal ultrasound at gestational age {{GA}} 10–14 weeks. Fetal sagittal section scan at a magnification that the fetus occupied at least 75% of the image. Measured is the maximum thickness of the subcutaneous translucency between the skin and the soft tissue overlying the cervical spine.		* '''nuchal translucency''' - (fetal nuchal-translucency thickness) An initial diagnostic ultrasound measurement in the fetal neck region carried out by trans-abdominal ultrasound at gestational age {{GA}} 10–14 weeks. Fetal sagittal section scan at a magnification that the fetus occupied at least 75% of the image. Measured is the maximum thickness of the subcutaneous translucency between the skin and the soft tissue overlying the cervical spine.

			* '''segmental aneuploidies''' - generated when a small piece of a chromosome is gained or lost during cell division, resulting in subchromosomal copy number (CN) changes.

	* '''single umbilical artery''' - (SUA) Placental cord with only a single placental artery (normally paired). This abnormality can be detected by ultrasound (colour flow imaging of the fetal pelvis) and is used as an indicator for further prenatal diagnostic testing for chromosomal abnormalities and other systemic defects. (More? [[Prenatal Diagnosis]] \| [[Ultrasound]])		* '''single umbilical artery''' - (SUA) Placental cord with only a single placental artery (normally paired). This abnormality can be detected by ultrasound (colour flow imaging of the fetal pelvis) and is used as an indicator for further prenatal diagnostic testing for chromosomal abnormalities and other systemic defects. (More? [[Prenatal Diagnosis]] \| [[Ultrasound]])

	* '''trimester''' - Clinical term used to describe and divide human pregnancy period (9 months) into three equal parts of about three calendar months. The first trimester corresponds approximately to embryonic development (week 1 to 8) of organogenesis and early fetal. The second and third trimester correspond to the fetal period of growth in size (second trimester) and weight (third trimester), as well as continued differentiation of existing organs and tissues. (More? [[Timeline human development]])		* '''trimester''' - Clinical term used to describe and divide human pregnancy period (9 months) into three equal parts of about three calendar months. The first trimester corresponds approximately to embryonic development (week 1 to 8) of organogenesis and early fetal. The second and third trimester correspond to the fetal period of growth in size (second trimester) and weight (third trimester), as well as continued differentiation of existing organs and tissues. (More? [[Timeline human development]])

	* '''triple markers''' - alpha-fetoprotein, human chorionic gonadotropin, and unconjugated estriol.		* '''triple markers''' - alpha-fetoprotein, human chorionic gonadotropin, and unconjugated estriol.

Z8600021 at 11:46, 9 December 2019

2019-12-09T11:46:56Z

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	===Articles===		===Articles===


	{{#pmid:28942922}}		{{#pmid:28942922}}

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	{{#pmid:27900612}}		{{#pmid:27900612}}

			{{#pmid:26237255}}

	{{#pmid:18084010}}		{{#pmid:18084010}}

Z8600021 at 00:47, 7 November 2019

2019-11-07T00:47:48Z

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			* '''First trimester uterine artery pulsatility index levels in euploid and aneuploid pregnancies'''{{#pmid:31616987\|PMID31616987}} "To examine whether the uterine artery PI is different in aneuploid and euploid pregnancies. METHODS: Retrospective case-matched study at the department of prenatal medicine at the University of Tuebingen, Germany. The study involved patients with complete data on first trimester screening for trisomies and preeclampsia except PlGF. For each case with trisomy 21 we randomly selected 50 cases with a euploid fetus where complete data on screening for aneuploidy and preeclampsia were also available. The uterine artery pulsatility index and the corresponding MoM values of euploid and the aneuploid population were compared with a Man-Whitney U test. RESULTS: The dataset consisted of 4591 singleton pregnancies. The karyotype was normal in 4500 cases and was abnormal in the remaining 91 pregnancies. There were 50 pregnancies with trisomy 21, 31 with trisomy 18 and 13, and 10 with triploidy. In the group with euploid fetuses, median uterine artery PI was 1.55 (0.99 MoM). In the group with trisomy 21, the median PI (1.42) and MoM (0.89) levels were both significantly lower than in the euploid (p < 0.001). However, the measurements in the trisomy 18 and 13 [1.61 (0.93 MoM)] and in the triploidy [1.99 (1.13 MoM)] groups were not significantly different from those in the euploid group (p = 0.468 and p = 0.632, respectively). CONCLUSION: In conclusion, uterine artery PI levels in the first trimester are slightly lower in pregnancies with trisomy 21. This knowledge may prove to be useful in cases where a low PAPP-A level is seen on the first trimester maternal serum biochemical evaluation to differentiate whether the more likely cause for this finding is placental dysfunction or aneuploidy, specifically trisomy 21."

	* '''Transcriptomic behavior of genes associated with chromosome 21 aneuploidies in early embryo development'''{{#pmid:30922649\|PMID30922649}} "To analyze how chromosome 21 (HSA21) ploidy affects global gene expression of early human blastocysts. A total of 26 high-quality donated embryos from in vitro fertilization (IVF) patients: trisomy 21 (n = 8), monosomy 21 (n = 10), and euploid (n = 8) blastocysts. Trisomy 21, monosomy 21, and euploid blastocysts were classified by comparative genomic hybridization. The global transcriptome of whole blastocysts was analyzed with small cell number RNA sequencing, and they were compared to understand the gene expression behavior at early development and its implications for embryo implantation. We identified 1,232 differentially expressed genes (false discovery rate <0.05) in monosomy 21 compared with euploid blastocysts associated with dysregulated functions in embryo development as the Rap1 signaling pathway. Curiously, Down syndrome in early development revealed fewer transcriptomic changes than expected. In addition, Down syndrome gene expression in neonates, children, and adults revealed that the number of deregulated genes increases across life stages from blastocysts to adults, suggesting a potential dosage-compensation mechanism for human chromosome 21. At the transcriptomic level, early development in Down syndrome is mainly dosage compensated. However, monosomy 21 is strongly transcriptionally affected because early development involving main functions is associated with embryo implantation."		* '''Transcriptomic behavior of genes associated with chromosome 21 aneuploidies in early embryo development'''{{#pmid:30922649\|PMID30922649}} "To analyze how chromosome 21 (HSA21) ploidy affects global gene expression of early human blastocysts. A total of 26 high-quality donated embryos from in vitro fertilization (IVF) patients: trisomy 21 (n = 8), monosomy 21 (n = 10), and euploid (n = 8) blastocysts. Trisomy 21, monosomy 21, and euploid blastocysts were classified by comparative genomic hybridization. The global transcriptome of whole blastocysts was analyzed with small cell number RNA sequencing, and they were compared to understand the gene expression behavior at early development and its implications for embryo implantation. We identified 1,232 differentially expressed genes (false discovery rate <0.05) in monosomy 21 compared with euploid blastocysts associated with dysregulated functions in embryo development as the Rap1 signaling pathway. Curiously, Down syndrome in early development revealed fewer transcriptomic changes than expected. In addition, Down syndrome gene expression in neonates, children, and adults revealed that the number of deregulated genes increases across life stages from blastocysts to adults, suggesting a potential dosage-compensation mechanism for human chromosome 21. At the transcriptomic level, early development in Down syndrome is mainly dosage compensated. However, monosomy 21 is strongly transcriptionally affected because early development involving main functions is associated with embryo implantation."

Z8600021 at 08:52, 5 Mayıs 2019

2019-05-05T08:52:35Z

← Older revision		Revision as of 19:52, 5 Mayıs 2019
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			* '''Transcriptomic behavior of genes associated with chromosome 21 aneuploidies in early embryo development'''{{#pmid:30922649\|PMID30922649}} "To analyze how chromosome 21 (HSA21) ploidy affects global gene expression of early human blastocysts. A total of 26 high-quality donated embryos from in vitro fertilization (IVF) patients: trisomy 21 (n = 8), monosomy 21 (n = 10), and euploid (n = 8) blastocysts. Trisomy 21, monosomy 21, and euploid blastocysts were classified by comparative genomic hybridization. The global transcriptome of whole blastocysts was analyzed with small cell number RNA sequencing, and they were compared to understand the gene expression behavior at early development and its implications for embryo implantation. We identified 1,232 differentially expressed genes (false discovery rate <0.05) in monosomy 21 compared with euploid blastocysts associated with dysregulated functions in embryo development as the Rap1 signaling pathway. Curiously, Down syndrome in early development revealed fewer transcriptomic changes than expected. In addition, Down syndrome gene expression in neonates, children, and adults revealed that the number of deregulated genes increases across life stages from blastocysts to adults, suggesting a potential dosage-compensation mechanism for human chromosome 21. At the transcriptomic level, early development in Down syndrome is mainly dosage compensated. However, monosomy 21 is strongly transcriptionally affected because early development involving main functions is associated with embryo implantation."

	* '''Inefficient Crossover Maturation Underlies Elevated Aneuploidy in Human Female Meiosis'''{{#pmid:28262352\|PMID28262352}} "Meiosis is the cellular program that underlies gamete formation. For this program, crossovers between homologous chromosomes play an essential mechanical role to ensure regular segregation. We present a detailed study of crossover formation in human male and female meiosis, enabled by modeling analysis. Results suggest that recombination in the two sexes proceeds analogously and efficiently through most stages. However, specifically in female (but not male), ∼25% of the intermediates that should mature into crossover products actually fail to do so. Further, this "female-specific crossover maturation inefficiency" is inferred to make major contributions to the high level of chromosome mis-segregation and resultant aneuploidy that uniquely afflicts human female oocytes (e.g., giving Down syndrome). Additionally, crossover levels on different chromosomes in the same nucleus tend to co-vary, an effect attributable to global per-nucleus modulation of chromatin loop size. Maturation inefficiency could potentially reflect an evolutionary advantage of increased aneuploidy for human females."		* '''Inefficient Crossover Maturation Underlies Elevated Aneuploidy in Human Female Meiosis'''{{#pmid:28262352\|PMID28262352}} "Meiosis is the cellular program that underlies gamete formation. For this program, crossovers between homologous chromosomes play an essential mechanical role to ensure regular segregation. We present a detailed study of crossover formation in human male and female meiosis, enabled by modeling analysis. Results suggest that recombination in the two sexes proceeds analogously and efficiently through most stages. However, specifically in female (but not male), ∼25% of the intermediates that should mature into crossover products actually fail to do so. Further, this "female-specific crossover maturation inefficiency" is inferred to make major contributions to the high level of chromosome mis-segregation and resultant aneuploidy that uniquely afflicts human female oocytes (e.g., giving Down syndrome). Additionally, crossover levels on different chromosomes in the same nucleus tend to co-vary, an effect attributable to global per-nucleus modulation of chromatin loop size. Maturation inefficiency could potentially reflect an evolutionary advantage of increased aneuploidy for human females."