Talk:Trisomy 18: Difference between revisions

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==2018==
==2018==
===Fetal fraction-based risk algorithm for non-invasive prenatal testing: screening for trisomy 13, 18, and triploidy in women with low cell-free fetal DNA===
Ultrasound Obstet Gynecol. 2018 Jul 16. doi: 10.1002/uog.19176. [Epub ahead of print]
McKanna T1, Ryan A1, Krinshpun S1, Kareht S1, Marchand K2, Grabarits C3, Ali M4, McElheny A5, Gardiner K6, LeChien K7, Hsu M8, Saltzman D9, Stosic M1, Martin K1, Benn P10.
Abstract
OBJECTIVE:
To identify pregnancies at increased risk for trisomy 13, trisomy 18, and triploidy attributable to low fetal fraction (FF).
METHODS:
A FF-based risk (FFBR) model was built using data from >165,000 singleton pregnancies referred for SNP-based non-invasive prenatal testing (NIPT). Based on maternal weight and gestational age, FF distributions for normal, trisomy 13, trisomy 18, and triploid pregnancies were constructed and used to adjust prior risks for these abnormalities. A risk cutoff of ≥1% was chosen to define pregnancies at high risk for trisomy 13, trisomy 18, or triploidy (i.e., a high FFBR score). The model was evaluated on an independent blinded set of pregnancies for which SNP-based NIPT did not return a result, and for which retrospectively gathered pregnancy outcome information was available.
RESULTS:
The evaluation cohort comprised 1,148 cases, of which approximately half received a high FFBR score. Compared with incidence rates expected based on maternal age (MA) and gestational age (GA), cases with a high FFBR score had a significantly increased rate of trisomy 13, trisomy 18, or triploidy combined (5.7% vs. 0.7%; p<0.001) and of unexplained pregnancy loss (14.7% vs 10.4% p<0.001). For cases that did not receive a high FFBR score, the incidence of a chromosome abnormality or loss was not significantly different than that expected based on MA and GA. In the study cohort, the sensitivity of the FFBR model for detection of trisomy 13, trisomy 18, or triploidy was 91.4% (95% CI: 76.9-98.2) with a positive predictive value of 5.7% (32/564; 95% CI: 3.9-7.9).
CONCLUSIONS:
For pregnancies with a FF too low to receive a result on standard NIPT, the FFBR algorithm can identify a subset of cases at increased risk for trisomy 13, trisomy 18, or triploidy. For the remainder of cases, the risk for a fetal chromosome abnormality was unchanged. This article is protected by copyright. All rights reserved.
This article is protected by copyright. All rights reserved.
KEYWORDS:
NIPT; fetal fraction; guidelines; maternal weight; pregnancy loss; prenatal screening; triploidy; trisomy
PMID: 30014528 DOI: 10.1002/uog.19176


===Enhanced First Trimester Aneuploidy Screening with Placental Growth Factor and Alpha Feto-Protein: Detection of Trisomies 18 and 13===
===Enhanced First Trimester Aneuploidy Screening with Placental Growth Factor and Alpha Feto-Protein: Detection of Trisomies 18 and 13===

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Cite this page: Hill, M.A. (2024, March 28) Embryology Trisomy 18. Retrieved from https://embryology.med.unsw.edu.au/embryology/index.php/Talk:Trisomy_18

OMIM

TRISOMY 18-LIKE SYNDROME

10 Most Recent

Note - This sub-heading shows an automated computer PubMed search using the listed sub-heading term. References appear in this list based upon the date of the actual page viewing. Therefore the list of references do not reflect any editorial selection of material based on content or relevance. In comparison, references listed on the content page and discussion page (under the publication year sub-headings) do include editorial selection based upon relevance and availability. (More? Pubmed Most Recent)


Trisomy 18

<pubmed limit=5>Trisomy 18</pubmed>

Edwards Syndrome

<pubmed limit=5>Edwards Syndrome</pubmed>

2018

Fetal fraction-based risk algorithm for non-invasive prenatal testing: screening for trisomy 13, 18, and triploidy in women with low cell-free fetal DNA

Ultrasound Obstet Gynecol. 2018 Jul 16. doi: 10.1002/uog.19176. [Epub ahead of print]

McKanna T1, Ryan A1, Krinshpun S1, Kareht S1, Marchand K2, Grabarits C3, Ali M4, McElheny A5, Gardiner K6, LeChien K7, Hsu M8, Saltzman D9, Stosic M1, Martin K1, Benn P10.

Abstract

OBJECTIVE: To identify pregnancies at increased risk for trisomy 13, trisomy 18, and triploidy attributable to low fetal fraction (FF). METHODS: A FF-based risk (FFBR) model was built using data from >165,000 singleton pregnancies referred for SNP-based non-invasive prenatal testing (NIPT). Based on maternal weight and gestational age, FF distributions for normal, trisomy 13, trisomy 18, and triploid pregnancies were constructed and used to adjust prior risks for these abnormalities. A risk cutoff of ≥1% was chosen to define pregnancies at high risk for trisomy 13, trisomy 18, or triploidy (i.e., a high FFBR score). The model was evaluated on an independent blinded set of pregnancies for which SNP-based NIPT did not return a result, and for which retrospectively gathered pregnancy outcome information was available. RESULTS: The evaluation cohort comprised 1,148 cases, of which approximately half received a high FFBR score. Compared with incidence rates expected based on maternal age (MA) and gestational age (GA), cases with a high FFBR score had a significantly increased rate of trisomy 13, trisomy 18, or triploidy combined (5.7% vs. 0.7%; p<0.001) and of unexplained pregnancy loss (14.7% vs 10.4% p<0.001). For cases that did not receive a high FFBR score, the incidence of a chromosome abnormality or loss was not significantly different than that expected based on MA and GA. In the study cohort, the sensitivity of the FFBR model for detection of trisomy 13, trisomy 18, or triploidy was 91.4% (95% CI: 76.9-98.2) with a positive predictive value of 5.7% (32/564; 95% CI: 3.9-7.9). CONCLUSIONS: For pregnancies with a FF too low to receive a result on standard NIPT, the FFBR algorithm can identify a subset of cases at increased risk for trisomy 13, trisomy 18, or triploidy. For the remainder of cases, the risk for a fetal chromosome abnormality was unchanged. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved. KEYWORDS: NIPT; fetal fraction; guidelines; maternal weight; pregnancy loss; prenatal screening; triploidy; trisomy PMID: 30014528 DOI: 10.1002/uog.19176

Enhanced First Trimester Aneuploidy Screening with Placental Growth Factor and Alpha Feto-Protein: Detection of Trisomies 18 and 13

J Obstet Gynaecol Can. 2018 Jul 16. pii: S1701-2163(18)30005-7. doi: 10.1016/j.jogc.2018.01.007. [Epub ahead of print]


Huang T1, Meschino WS2, Rashid S3, Dennis A3, Mak-Tam E3, Cuckle H4. Author information Abstract OBJECTIVES: To assess the performance of first trimester combined screening (FTS) when enhanced with placental growth factor and alpha feto-protein in the detection of trisomies 18 and 13. METHODS: A retrospective case-control study. Marker parameters were derived using frozen serum samples. Multivariate Gaussian modelling predicted the detection rate (DR) and false-positive rate (FPR) for trisomies 18 and 13 with FTS and enhanced first trimester screening (eFTS) using the risk of trisomy 21 alone and an additional risk cut-off for trisomy 18, or trisomies 18 or 13. RESULTS: There were 83 trisomy 18, 22 trisomy 13, and 588 controls. The median placental growth factor levels in trisomies 18 and 13 were 0.75 and 0.65 multiple of the median of controls, respectively (both P <0.0001). There were no statistically significant differences in alpha feto-protein levels. Modelling predicts that using a trisomy 21 risk cut-off alone, at FPR of 3%, eFTS increases the DR for trisomies 18 and 13 by 0.6-0.8% compared with FTS. Additionally using a trisomy 18 risk cut-off, at an extra FPR of 0.2%, eFTS increased the DR by 0.6-0.9% over FTS; using a trisomy 18 or 13 risk cut-off did not further increase detection for FTS or eFTS. The increase in DR was greater at higher FPR. CONCLUSION: eFTS increases the detection of trisomies 18 and 13 to a small extent. Copyright © 2018 Society of Obstetricians and Gynaecologists of Canada. Published by Elsevier Inc. All rights reserved. KEYWORDS: First trimester; alpha feto-protein; placental growth factor; screening; trisomy 13; trisomy 18 PMID: 30025867 DOI: 10.1016/j.jogc.2018.01.007

2016

Fetal outcome of trisomy 18 diagnosed after 22 weeks of gestation: Experience of 123 cases at a single perinatal center

Congenit Anom (Kyoto). 2016 Jan;56(1):35-40. doi: 10.1111/cga.12118.

Nagase H1,2, Ishikawa H1, Toyoshima K3, Itani Y3, Furuya N4, Kurosawa K5, Hirahara F2, Yamanaka M6.

Abstract

To investigate the pregnancy outcome of the fetuses with trisomy 18, we studied 123 cases of trisomy 18 who were born at our hospital from 1993 to 2009. Among them, 95.9% were diagnosed with trisomy 18 prenatally. Prenatal ultrasound findings showed fetal growth restriction in 77.2%, polyhydramnios in 63.4% and congenital heart defects in 95.1%. For 18 cases, cesarean section (C-section) was chosen, and for 75 cases, transvaginal delivery was chosen. Premature delivery occurred in 35.5%. Stillbirths occurred in 50 cases (40.7%). Fetal demise before onset of labor occurred in 30 cases and fetal demise during labor occurred in 20 cases which was 26.7% of vaginal deliveries. Among the 73 live-born infants, the survival rate for 24 h, 1 week, 1 month and 1 year were 63%, 43%, 33% and 3%. The median survival time was 3.5 days. There was no significant difference between the survival time of C-section and that of vaginal delivery. However, for the births involving breech presentation, the survival time of C-section was significantly longer than that of vaginal delivery. When the fetus is diagnosed with trisomy 18, the parents have to make many choices. These findings constitute critical information in prenatal counseling to the couples whose fetuses have been found to have trisomy 18, especially when they choose palliative approaches in the perinatal management. © 2015 Japanese Teratology Society. KEYWORDS: management; palliative care; prenatal ultrasound findings; prognosis; trisomy 18

  • Fetal outcome of trisomy 18 diagnosed after 22 weeks of gestation: Experience of 123 cases at a single perinatal center[1]
  • 123 cases (1993 to 2009) 95.9% prenatal diagnosis
  • ultrasound - fetal growth restriction in 77.2%, polyhydramnios in 63.4% and congenital heart defects in 95.1%.
  • 18 cases, cesarean section (C-section)
  • 75 cases, transvaginal delivery Premature delivery occurred in 35.5%.
  • Stillbirths occurred in 50 cases (40.7%).
  • Fetal demise before onset of labor in 30 cases and fetal demise during labor in 20 cases which was 26.7% of vaginal deliveries.
  • 73 live-born infants, the survival rate for 24 h, 1 week, 1 month and 1 year were 63%, 43%, 33% and 3%. The median survival time was 3.5 days."


PMID 26104883

2013

Other External links

http://en.wikipedia.org/wiki/File:Overlapping_fingers.JPG

2012

The trisomy 18 syndrome

Orphanet J Rare Dis. 2012 Oct 23;7(1):81. [Epub ahead of print]

Cereda A, Carey JC.

Abstract

The trisomy 18 syndrome, also known as Edwards syndrome, is a common chromosomal disorder due to the presence of an extra chromosome 18, either full, mosaic trisomy, or partial trisomy 18q. The condition is the second most common autosomal trisomy syndrome after trisomy 21. The live born prevalence is estimated as 1/6,000-1/8,000, but the overall prevalence is higher (1/2500-1/2600) due to the high frequency of fetal loss and pregnancy termination after prenatal diagnosis. The prevalence of trisomy 18 rises with the increasing maternal age. The recurrence risk for a family with a child with full trisomy 18 is about 1%.Currently most cases of trisomy 18 are prenatally diagnosed, based on screening by maternal age, maternal serum marker screening, or detection of sonographic abnormalities (e.g., increased nuchal translucency thickness, growth retardation, choroid plexus cyst, overlapping of fingers, and congenital heart defects ). The recognizable syndrome pattern consists of major and minor anomalies, prenatal and postnatal growth deficiency, an increased risk of neonatal and infant mortality, and marked psychomotor and cognitive disability. Typical minor anomalies include characteristic craniofacial features, clenched fist with overriding fingers, small fingernails, underdeveloped thumbs, and short sternum. The presence of major malformations is common, and the most frequent are heart and kidney anomalies. Feeding problems occur consistently and may require enteral nutrition.Despite the well known infant mortality, approximately 50% of babies with trisomy 18 live longer than 1 week and about 5-10% of children beyond the first year. The major causes of death include central apnea, cardiac failure due to cardiac malformations, respiratory insufficiency due to hypoventilation, aspiration, or upper airway obstruction and, likely, the combination of these and other factors (including decisions regarding aggressive care). Upper airway obstruction is likely more common than previously realized and should be investigated when full care is opted by the family and medical team.The complexity and the severity of the clinical presentation at birth and the high neonatal and infant mortality make the perinatal and neonatal management of babies with trisomy 18 particularly challenging, controversial, and unique among multiple congenital anomaly syndromes. Health supervision should be diligent, especially in the first 12 months of life, and can require multiple pediatric and specialist evaluations.

PMID 23088440

http://www.ojrd.com/content/7/1/81/abstract

Table

Frequency Organ/System Prevalent type of malformation
Common (>75%) heart septal defects, patent ductus arteriosus, and polyvalvular disease
Frequent (25-75%) genitourinary horseshoe kidney
Less frequent (5-25%) gastrointestinal

central nervous system

craniofacial

eye

limb

omphalocele, esophageal atresia with tracheo-esophageal fistula, pyloric stenosis, Meckel diverticulum

cerebellar hypoplasia, agenesis of corpus callosum, polymicrogyria, spina bifida

orofacial clefts

microphthalmia, coloboma, cataract, corneal opacities

radial aplasia/hypoplasia

1989

J Am Coll Cardiol. 1989 Jun;13(7):1586-97. Cardiac malformations in trisomy-18: a study of 41 postmortem cases. Van Praagh S1, Truman T, Firpo A, Bano-Rodrigo A, Fried R, McManus B, Engle MA, Van Praagh R. Author information Abstract The cardiac malformations in 41 karyotyped and autopsy cases of trisomy-18 are presented in detail. The salient findings were a ventricular septal defect in all cases; tricuspid valve anomalies in 33 cases (80%); pulmonary valve anomalies in 30 (70%); aortic valve malformations in 28 (68%); mitral valve anomalies in 27 (66%); polyvalvular disease (that is, malformations of more than one valve) in 38 (93%); a subpulmonary infundibulum (conus) in 40 (98%); a bilateral conus with a short subaortic infundibulum in 1 case with double outlet right ventricle (this being the only documented case of bilateral infundibulum in trisomy-18); double outlet right ventricle in 4 cases (10%), three having a subpulmonary infundibulum only and all 4 having mitral atresia; tetralogy of Fallot in 6 cases (15%), 2 having pulmonary atresia; and a striking absence of transposition of the great arteries and inversion at any level (visceral or cardiac), findings that appear to be characteristic of all trisomies. These data suggest that excessive chromosomal material (as in trisomies) may result in situs solitus at all levels. The malformations of the atrioventricular and semilunar valves were characterized by redundant or thick myxomatous leaflets, long chordae tendineae and hypoplastic or absent papillary muscles. The ventricular septal defect was associated with anterosuperior conal septal malalignment in 25 cases (61%). On the basis of the characteristic valvular lesions, the type of ventricular septal defect and the absence of transposition or inversions, two-dimensional echocardiographic diagnosis of trisomy-18 in the fetus may become possible. PMID: 2723271

The cardiac malformations in 41 karyotyped and autopsy cases of trisomy-18 are presented in detail. The salient findings were a ventricular septal defect in all cases; tricuspid valve anomalies in 33 cases (80%); pulmonary valve anomalies in 30 (70%); aortic valve malformations in 28 (68%); mitral valve anomalies in 27 (66%); polyvalvular disease (that is, malformations of more than one valve) in 38 (93%); a subpulmonary infundibulum (conus) in 40 (98%); a bilateral conus with a short subaortic infundibulum in 1 case with double outlet right ventricle (this being the only documented case of bilateral infundibulum in trisomy-18); double outlet right ventricle in 4 cases (10%), three having a subpulmonary infundibulum only and all 4 having mitral atresia; tetralogy of Fallot in 6 cases (15%), 2 having pulmonary atresia; and a striking absence of transposition of the great arteries and inversion at any level (visceral or cardiac), findings that appear to be characteristic of all trisomies.

  1. <pubmed>26104883</pubmed>