Long-term survival of full trisomy 13 in a 14 year old male: a case report.

Long term survival for the cases of trisomy 13 into over a first decade is very rare. We reported here the case of a 14-year-old male karyotype with full type of trisomy 13. In this clinical phenomenon, the case had typical facial, finger and limb anomalies for trisomy 13. Arterial septal defect and patent ductus arteriosus were recognized using ultrasonography after birth. Major cerebral malformation such as holoprosencephaly or cerebellar hypoplasia were also not revealed. After 5 months of his age, artificial ventilation therapy for dyspnea associated with laryngomalacia was required. A tracheotomy was performed at 6 months of his age. After 12 years old, intractable partial epilepsy was recognized. For his partial seizures, a treatment with a combination of two anti-epileptic drugs, valproic acid and levetiracetam, were advised. Now he is alive for 14-years-old and he is the 4th longest surviving patient with full karyotype of trisomy 13.

Cell-free DNA analysis in maternal plasma in cases of fetal abnormalities detected on ultrasound examination.

OBJECTIVE: To evaluate the utility of noninvasive prenatal testing using cell-free circulating fetal DNA for detection of the three main autosomal fetal trisomies in the setting of ultrasonographically identified fetal anomalies. METHODS: Nine hundred patients at risk for fetal aneuploidy with or without ultrasonography anomalies and who underwent invasive procedures were included in the study. Cell-free DNA analysis was performed by massive parallel sequencing during a multicenter, noninterventional, prospective study and the results were compared with a fetal karyotype. RESULTS: Among all 900 pregnancies, cell-free DNA identified 76 of 76 (100%) fetal Down syndrome, 22 of 25 (88%) trisomy 18, and 12 of 12 (100%) trisomy 13. In those with a normal ultrasonogram and normal cell-free DNA analysis, karyotype identified 2 of 483 (0.4%) additional aneuploidies other than trisomies 13, 18, and 21. In those with an abnormal ultrasonogram and a normal cell-free DNA analysis, there were 23 of 290 (7.9%) additional pathogenic karyotypes. These additional aneuploidies included sex chromosome abnormalities and triploidy. The rates of additional aneuploidies not identifiable by standard cell-free DNA screening in the two groups is significantly different at P<.01. CONCLUSION: In women with fetal abnormalities by ultrasonography, the rate of pathogenic chromosome abnormalities missed by cell-free DNA was 8%. Noninvasive prenatal testing should not be offered to women with fetal abnormalities because a negative result is falsely reassuring. LEVEL OF EVIDENCE: III.

First trimester screening for other trisomies than trisomy 21, 18, and 13.

OBJECTIVE: The objective of the study was to evaluate the performance of first trimester combined screening in cases of placental/fetal, mosaic or non-mosaic, autosomal trisomy other than trisomy 21, 18, or 13, and in cases of aneuploidy for a marker chromosome with focus on biochemical markers. METHOD: We identified 66 cases in three large databases including 357 675 pregnancies from October 2003 to January 2014. RESULTS: Seventy-seven percent of the 66 cases were screened positive at the combined first trimester screening (cFTS) for trisomy 21 or trisomy 18 or 13. The multiple of median (MoM) of Pregnancy Associated plasma protein A (PAPP-A) of the different aneuploidy groups ranged from 0.2 to 0.5 MoM, whereas the MoM of maternal serum free - ß - human chorionic gonadotropin (FßhCG) was approximately 1.0 MoM. The exceptions being 0.2 MoM for cases involving chromosome 8 (n = 7) and 0.5 MoM for cases involving chromosome 9 (n = 3). The nuchal translucency MoM was approximately 1.0 MoM in all aneuploidy groups. CONCLUSION: The cFTS program for trisomy 21, 18, and 13 is also sensitive to a broad range of rare chromosomal trisomies and chromosomal mosaicisms, primarily because of a strong detection capacity of PAPP-A MoM.

Screening for chromosomal abnormalities by first trimester combined screening and noninvasive prenatal testing.

PURPOSE: To examine combined first trimester screening (FTS), noninvasive prenatal testing (NIPT) and a two-step policy that combines FTS and NIPT in screening for aneuploidy. MATERIALS AND METHODS: Retrospective study involving 21,052 pregnancies where FTS was performed at the Praxis Praenatal.de in Duesseldorf, Germany. In each case, the sum risk of trisomy 21, 18 and 13 was computed. We assumed that NIPT detects 99 %, 98 %, 90 % and 99 % of cases with trisomy 21, 18, 13 and sex chromosomal abnormalities and that the false-positive rate is 0.5 %. The following screening policies were examined: NIPT or FTS with sum risk cut-offs of 1 in 50 and 1 in 250 in all patients or a two-step-policy with FTS in all patients followed by NIPT in the intermediate sum risk group. For the intermediate risk group, sum risk cut-offs of 1 in 50 and 1 in 1000 and 1 in 150 and 1 in 500 were used. RESULTS: There were 127, 34, 13 and 15 pregnancies with trisomy 21, 18, 13 and sex chromosomal abnormalities. 23 fetuses had other chromosomal abnormalities with an increased risk for adverse outcome that are not detectable by NIPT. 20,840 pregnancies were classified as normal as ante- and postnatal examinations did not show any signs of clinically significant chromosomal abnormalities. FTS with a sum risk cut-off of 1 in 50 and 1 in 250 detects 81 % and 91 % for all aneuploidies. NIPT detects 88 % of the respective pregnancies. The 2-step approach with sum risk cut-offs of 1 in 50 and 1 in 1000 detects 94 % of all aneuploidies. With sum risk cut-offs of 1 in 150 and 1 in 500, the detection rate is 93 %. CONCLUSION: A 2-step policy with FTS for all patients and NIPT in the intermediate risk group results in the highest detection rate of all aneuploidies.

Biparietal diameter at 11 to 13 weeks' gestation in fetuses with holoprosencephaly.

OBJECTIVE: Studies have suggested that fetuses with holoprosencephaly have smaller head size, demonstrated as early as the first trimester. However, the majority of these cases were diagnosed in the second or third trimesters. The aim of this study was to investigate biparietal diameter (BPD) measured at 11 to 13 weeks' gestation in fetuses with holoprosencephaly. METHODS: This was a retrospective study in which BPD was measured at 11 to 13 weeks in 34 fetuses with prenatal diagnosis of holoprosencephaly and 7775 unaffected controls. BPD values were converted into multiples of the expected median (MoM) after adjustment for crown-rump length and maternal characteristics. RESULTS: The median gestational age at the BPD recording was 12.6 (interquartile range 12.3-13.0) weeks. The nuchal translucency was increased (≥3mm) in 58.8% of the cases. Aneuploidy was confirmed in 73.5% of the cases; the commonest was trisomy 13 (50.0%). BPD values at 11 to 13 weeks were below the 5(th) centile in 32.4% of cases and below the 50(th) centile in 67.6%. BPD MoM values were significantly smaller than in the control group (median: 0.98; interquartile range: 0.90-1.06 vs 1.00; 0.96-1.04 MoM, p = 0.03). CONCLUSION: Fetuses with holoprosencephaly have a smaller BPD in the first trimester. This property may be useful in early diagnosis.

[Twin pregnancy discordant for trisomy 13: three cases]. / Gestación gemelar con un feto con síndrome de Patau (trisomía 13): tres casos clínicos.

BACKGROUND: The association between Patau's syndrome and multiple pregnancy is extremely rare. This paper reports three cases with different obstetric treatment. CASE 1: Dichorionic diamniotic twin pregnancy with a fetus affected by trisomy 13 diagnosed at 16 weeks of gestation. The pregnancy was managed conservatively resulting in the delivery of twins at 38 weeks. The structurally normal twin was male survived without sequelae, but the female fetus with trisomy 13 died shortly after delivery. CASE 2: Dichorionic diamniotic twin pregnancy. At 14 weeks of pregnancy, one of the fetus affected by trisomy 13 showed an early intrauterine growth restriction and a cystic hygroma. At 16 weeks of pregnancy the abnormal twin died spontaneously. Avaginal delivery occurred at 38 weeks being born a healthy male. CASE 3: Dichorionic diamniotic twin pregnancy. The trisomy 13 fetus had been diagnosed at 17 weeks of pregnancy and showed a cardiopathy. At 32 weeks of gestation a selective fetal reduction was performed. Vaginal delivery occurred at 35 weeks and a healthy newborn was born. CONCLUSION: Patau's syndrome has an unfortunate fetal and neonatal outcome. It is important an early diagnosis to establish the best strategy to minimize the risk of the healthy twin.

Dilated fourth ventricle in fetuses with trisomy 18, trisomy 13 and triploidy at 11-13 weeks' gestation.

OBJECTIVE: To determine if in fetuses with aneuploidies the diameter of the fourth cerebral ventricle at 11-13 weeks' gestation is different from euploid fetuses. METHODS: The fourth ventricle at 11-13 weeks' gestation was assessed in 62 cases of trisomy 21, 32 of trisomy 18, 10 of trisomy 13, and 12 of triploidy and compared to 410 normal euploid fetuses. Transvaginal sonography was carried out and 3D brain volumes were acquired. The fetal head was assessed in an axial plane and the diameter of the fourth ventricle was measured. Values in aneuploid and euploid fetuses were compared. RESULTS: The diameter of the fourth ventricle in trisomy 18, trisomy 13 and triploidy, but not in trisomy 21, was significantly higher than in euploid fetuses. In the euploid fetuses the median diameter of the fourth ventricle was 1.9 mm and the 95th percentile was 2.5 mm. The measurements were above the median and the 95th percentile in 25 (78.1%) and 17 (53.1%) cases of trisomy 18, in 10 (100%) and 8 (80.0%) of trisomy 13, and in 10 (83.3%) and 10 (83.3%) of triploidy. CONCLUSIONS: In trisomy 18, trisomy 13 and triploidy the diameter of the fourth ventricle at 11-13 weeks' gestation is increased.

First trimester diagnosis of 13q-syndrome associated with increased fetal nuchal translucency thickness. Clinical findings and systematic review.

13q-syndrome is a rare chromosomal disorder caused by partial deletion of the long arm of chromosome 13 with variable phenotypic presentation. Further sonographic features involve fetal growth restriction, bradycardia, encephalocele, facial dysmorphism and upper extremity deformity. We report a case of 13q-syndrome presenting as increased nuchal translucency diagnosed by chromosome studies and confirmed by array comparative genomic hybridization (CGH) analysis in the first trimester of pregnancy. Pregnancy was terminated at 14 weeks' gestation. The parents did not give consent for a postmortem examination. Furthermore we performed a systematic review of the international literature on previous cases of 13q-syndrome diagnosed prenatally. Our case emphasizes the importance of a detailed 11-14 week ultrasound assessment in diagnosing fetal chromosomal aberrations in combination with the modern aspects of array CGH, thus providing more precise and rapid prenatal diagnosis.

Lateral ventricles in fetuses with aneuploidies at 11-13 weeks' gestation.

OBJECTIVE: To examine the possible association between aneuploidies and fetal lateral cerebral ventriculomegaly in the first trimester of pregnancy. METHODS: Three-dimensional brain volumes were acquired by transvaginal ultrasound examination at 11-13 weeks' gestation in 410 euploid fetuses and 63 fetuses with trisomy 21, 34 with trisomy 18 and seven with trisomy 13. Lateral ventricles were assessed in a transverse view, just above the roof of the third ventricle and measurements of the areas of the lateral ventricles and choroid plexuses were obtained. The ratio between choroid plexus and lateral ventricle areas (CLR) was calculated. Measurements in aneuploid fetuses were compared to those in euploid fetuses. RESULTS: In euploid fetuses the lateral ventricle and choroid plexus areas increased, whereas the CLR decreased with fetal biparietal diameter. In fetuses with trisomy 21, lateral ventricle and choroid plexus areas were smaller but CLR was not significantly different from that in euploid fetuses. In trisomy 18 and 13 fetuses, CLR was significantly smaller than in euploid fetuses. The CLR was below the 5(th) centile of normal range in 11 (32.4%) fetuses with trisomy 18 and in six (85.7%) with trisomy 13. CONCLUSION: There is evidence of ventriculomegaly at 11-13 weeks' gestation in most fetuses with trisomy 13 and one third of fetuses with trisomy 18.

Thymic-thoracic ratio in fetuses with trisomy 21, 18 or 13.

OBJECTIVES: To assess thymic size expressed as the thymic-thoracic ratio (TT-ratio) in fetuses with trisomy 21, 18 or 13. METHODS: The TT-ratio, the quotient of the anteroposterior thymic and the intrathoracic mediastinal diameter, was measured in 65 trisomic fetuses between 15 and 36 weeks' gestation, including 30 cases with trisomy 21, 19 with trisomy 18 and 16 with trisomy 13. In addition these 65 fetuses were divided into two groups, according to whether they showed growth that was appropriate-for-gestational age (AGA) (n = 39) or intrauterine growth restriction (IUGR) (n = 26). Measurements were compared with reference ranges from 302 normal fetuses. RESULTS: The TT-ratio was low in 27.7% (n = 18) of the 65 fetuses with aneuploidy. In comparison to normal fetuses (mean TT-ratio, 0.44), those with trisomy 18 or 21 had a significantly smaller TT-ratio (mean, 0.38 (P < 0.001) and 0.40 (P < 0.05), respectively), while those with trisomy 13 did not (mean, 0.43). These values were not as low as those observed previously in fetuses with del.22q11, suggesting a mechanism involving accelerated thymic involution rather than primary thymic hypoplasia. Furthermore, the TT-ratio was significantly lower than normal in both AGA (P < 0.05) and IUGR (P < 0.001) fetuses. CONCLUSION: Fetuses with trisomy 18 or 21, but not trisomy 13, have a small thymus, suggesting accelerated thymic involution in utero. IUGR may contribute to the reduced thymic size in trisomy 18 fetuses. Trisomy 21 fetuses seem to have additional factors leading to a small thymus which could be a possible confirmation of the reduced immune response observed in fetuses and neonates with Down syndrome.

Combined ultrasound and biochemistry for risk evaluation in the first trimester: the Stockholm experience of a new web-based system.

OBJECTIVE: To evaluate the performance of a new first trimester web-based software for the detection of chromosomal anomalies using a combination of ultrasound and biochemistry. DESIGN: Registry-based cohort study. SETTING: Ultrasound units in the Stockholm region. POPULATION: 20 710 women with singleton pregnancies were examined at 11(+0) to 13(+6) weeks' gestational age during a three-year period 2006-2009. METHODS: The risks for trisomy 21, 13 and 18 were calculated using a combination of maternal age, serum markers and nuchal translucency. Individual risk estimates were calculated and then reported to a web-based system using a new algorithm based on likelihood ratios of each marker derived from Gaussian distributions in normal and affected pregnancies. MAIN OUTCOME MEASURES: The impact on rates of invasive testing and the incidence of children born with Down's syndrome after implementing the method. RESULTS: Approximately a third of all pregnant women in the region were examined with the combined test. The detection and test positive rates for Down's syndrome was 90 and 6.8%, respectively. Invasive testing among pregnant women decreased from 15 to 8% after introducing the method but the incidence of children born with Down's syndrome did not decrease during the study period. CONCLUSION: The new web-based software is an effective method for the detection of trisomy 21 with similar performance compared to other programs. However, it needs to be offered to all pregnant women to have an impact on the incidence of Down's syndrome.

The absence of the vomer in the first and early second trimester of pregnancy - a new marker of trisomy 21 and trisomy 13.

PURPOSE: The aim of this study was to measure the two frontomaxillo-facial (FMF) angles: the FMF-vomer (FMF-v) and the FMF-palate (FMF-p), and to visualize the vomer in the 1(st) and early 2(nd) trimester, in order to ascertain whether they can be used as markers for trisomy 21 and trisomy 13. MATERIALS AND METHODS: A 2D ultrasound scan was performed in the 340 normal and 12 abnormal pregnancies, using the linear, convex and endovaginal probes. RESULTS: We visualized the FMF angles within 1 to 5 minutes in 253 (72 %) of cases by using the linear probe. FMF-v angle was significantly smaller that the FMF-p angle (79.8° vs. 89.7°, 71.5° vs. 84.5° for the two trimesters, respectively), and that the value of both angles decreased in the second trimester. There was not one single case of trisomy in which vomer could be identified in the 1 (st) and early 2 (nd) trimester. The FMF-p angle failed to present difference between normal cases and the ones with trisomy (89.5°). There was not one single case of trisomy (21 or 13) in which vomer or FMF-v could be identified in the first or early second trimester. The diagnostic accuracy of vomer as a marker for trisomy was 0.985. CONCLUSION: If the vomer cannot be visualized in the 1 (st) and early 2 (nd) trimester, it is important to check the karyotype, and it is not necessary to measure the FMF-p angle. The high resolution probe (L 12 - 5 Mhz) enables easier assessment of the vomer.

Screening for trisomies in dichorionic twins by measurement of fetal nuchal translucency thickness according to the mixture model.

OBJECTIVE: To examine the distribution of fetal nuchal translucency (NT) thickness in dichorionic twins and investigate the effect of the correlation between NT measurements in each twin pair on the performance of screening for trisomies. METHODS: The distribution of fetal NT for crown-rump length (CRL) was examined in 5646 dichorionic twin pregnancies, including 103 with fetal trisomies 21, 18 or 13. The correlation in fetal NT in each euploid twin pregnancy was estimated. RESULTS: The distribution of NT in both euploid and trisomic fetuses was consistent with the mixture model in singleton pregnancies. In the euploid pregnancies, there was a correlation in log NT measurements in each twin pair (r = 0.42, 95% CI: 0.39-0.45) and, after removal of the effect of the operator, this correlation was reduced to 0.34. Allowing for this correlation in risk assessment for trisomies had a major impact on the estimated patient-specific risk but had little effect on the overall performance of screening. CONCLUSIONS: In dichorionic twin pregnancies, the mixture model of distributions of NT can be applied as in singletons. In screening for trisomies, the correlation in NT measurements between the fetuses should be taken into account in the estimation of patient-specific risks.

Prenatal diagnosis of a case of partial monosomy/monosomy 13 mosaicism: 46,XX,r(13)(p11q33)/45,XX,-13 suspected by nuchal fold translucency increasing.

Large numbers of patients with deletions of the long arm of chromosome 13 have been described. However, only a few instances have been reported of monosomy 13/r(13) mosaicism. A 31-year-old Japanese woman underwent an ultrasound tomographic screening, which detected a fetus with a nuchal translucency (NT) of >5.8mm, indicating an increased risk of fetal chromosomal abnormality. An amniocentesis (AC) was performed, and the karyotype was 46,XX,r(13)(p11q33)[18] / 45XX[12]. Ultrasound showed echogenic skin edema. Phenotype of the fetus after delivery revealed some anomalies, including hyponasal bridge, hypertelorism, ambiguous genitalia with huge clitoris, low-set ear, neck edema and webbing.Deletion of the long arm of chromosome 13 is associated with a wide spectrum of abnormalities, including retinoblastoma, mental and growth retardation, brain malformations, heart defects, distal limb deformities, and digestive, urogenital, and other abnormalities. The present case, however, had anomalies which were too faint to be detected by ultrasound tomography. Prenatal diagnosis of deletion 13q syndrome is rare. A number of reports have documented an association between increased NT and chromosomal defects. Ultrasound did not identify any major anomaly in this case, however amniocentesis was able to detect this rare abnormality.

A mixture model of nuchal translucency thickness in screening for chromosomal defects: validation of a single operator dataset.

OBJECTIVE: (1) To validate the mixture model in a single operator dataset and (2) to compare the detection rates for fetal chromosomal defects obtained from the mixture model with those obtained from either the delta nuchal translucency (NT) or log multiple of the median (MoM) approach. METHODS: Database query, viable singletons [crown-rump length (CRL) 45-84 mm corresponding to 11-13(+6) weeks], December 1997 to November 2006, examined by Adam Gasiorek-Wiens, the statistical mixture model was applied. RESULTS: Seventy-four of 4171 were lost to follow-up (1.8%), 4097 singleton pregnancies included trisomy 21 (n = 34, 0.8%), trisomy 18 (n = 20, 0.5%), trisomy 13 (n = 8, 0.2%), Turner syndrome (n = 9, 0.2%) and other chromosomal abnormalities (n = 14, 0.3%). The main findings are that (1) the log-transformed NT measurements follow a mixture of two Gaussian distributions and (2) the criteria to apply either the delta-NT or log MoM models are not met. In the normal group, the majority of NT measurements were dependent on the CRL, a small group showed a median independent of the CRL. In the abnormal group it was the opposite. For a 5% false-positive rate (FPR), the trisomy 21 detection rate was 83%. CONCLUSIONS: The use of the mixture model in a single operator dataset produces results compatible with the original study. The mixture model has thus been validated.

Heterokaryotypic pregnancy: monozygotic monochorionic twins discordant for trisomy 13.

BACKGROUND: The occurrence of a discordant chromosomal abnormality in monozygotic twins is an extremely rare condition. CASE: We report the prenatal sonographic findings and cytogenetic studies in a monochorionic twin pregnancy discordant for severe fetal anomalies. Amniocenteses demonstrated heterokaryotypia for trisomy 13 in monozygotic twins. The pregnancy was managed conservatively, resulting in the delivery of discordant twins at 32 weeks. The structurally normal twin survived without sequelae, but the abnormal twin died shortly after delivery. CONCLUSIONS: This report adds to the literature the second known case of a spontaneously conceived monochorionic twin pregnancy discordant for trisomy 13 and highlights the necessity of sampling both fetuses in cases of monochorionic twins presenting with discordant structural anomalies.