Natural history of trisomy 18 and trisomy 13: I. Growth,physical assessment,medical histories,survival, and recurrence risk

The natural history of trisomy 18 and trisomy 13 was investigated using data derived from parent questionaires and medical records from 98 families with an index case of trisomy 18 and 32 families with an index case of trisomy 13. Data are presented on pregnancy, delivery, survival, medical complications, immunizations, growth, cause of death, cytogenetics, and recurrence risk. Half of the trisomy 18 babies were delivered by C-section. Fetal distress was a factor in half, and the only reason in a third of C-section deliveries. One minute Apgar scores were significantly lower in C-section and breech deliveries. There were more small for gestational age babies than in the general population, but most of the low birth weight new borns were small for gestational age, unlike the general population. Survival in this group of children was better than in other studies due to ascertainment bias. There were more girls than boys at all ages for both conditions, and the sex ratio decreased with time. Growth curves for length, weight, head circumference, and weight vs height are provided. Long-term survival did not appear to be due to mosaicism. We found no adverse reactions attributable to immunizations. At age 1 year there was an average of approximately 2 operations per living child. We report the second case of successful major cardiac surgery in a trisomy 18 child. Almost 70% of deaths were attributed to cardiopulmonary arrest. The sibling recurrence risk for trisomy 18 or trisomy 13 was 0.55%. © 1994 Wiley-Liss, Inc.     

Natural outcome of trisomy 13, trisomy 18, and triploidy after prenatal diagnosis

Trisomy 13, trisomy 18, and triploidy belong to the chromosomal abnormalities which are compatible with life, but which are also associated with a high rate of spontaneous abortion, intrauterine death, and a short life span. This study was conducted to analyze natural outcome after prenatal diagnosis of these disorders. Between January 1, 1999 and December 31, 2009, we investigated all amniocenteses and chorionic villus biopsies carried out at our department. All cases with fetal diagnosis of triploidy, trisomy 13, and 18 were analyzed, with a focus on cases with natural outcome. Overall, 83 (78%) cases of pregnancy termination and 24 (22%) patients with natural outcome (NO) were identified. The NO group included 15 cases of trisomy 18, six cases of triploidy, and three cases of trisomy 13. No case of triploidy was born alive. The live birth rate was 13% for trisomy 18 and 33% for trisomy 13. The three live-born infants with trisomy 13 and 18 died early after a maximum of 87 hr postpartum. Our data are consistent with the literature concerning outcome of triploidy, with none or only a few live births. Analyzes of trisomy 13 and 18 indicate a very short postnatal life span. Different study designs and diverse treatment strategies greatly affect the fetal and neonatal outcome of fetuses with triploidy, trisomy 13, and 18. More studies analyzing natural outcome after prenatal diagnosis of these chromosomal abnormalities are needed. Non-termination of these pregnancies remains an option, and specialists advising parents need accurate data for counseling.     

Trisomy 13/trisomy 18 mosaicism in an infant

Cytogenetic analysis of amniotic fluid cells from a 31-week-old fetus suffering from polyhydramnios revealed that there were two cell lines, each with either trisomy 13 or trisomy 18. We studied the origin and mechanism of formation of this unique mixoploidy by tracing chromosomal heteromorphisms as genetic markers, and showed no discordance of parent-child transmission between the two cell lines in any of the heteromorphisms examined. The result indicated that the mixoploidy is not chimerism but mosaicism and that the mechanism of mosaic development is most likely due to two non-disjunctional events which had occurred independently at the two-cell stage of the zygote. A girl was born at the 38th gestational week and her clinical features were mainly those for trisomy 13. Chromosome analysis of the newborn confirmed +13/+18 mosaicism in fibroblasts from the skin and chorionic plate, while cord blood lymphocytes and chorionic villus cells showed only the +18 cell line.     

Rates and survival of individuals with trisomy 13 and 18 Data from a 10-year period in Denmark

Rates and survival figures for trisomy 13 and trisomy 18 have been calculated for Denmark (DK) based on a 10-year period (1977-86). The data have been ascertained through The Danish Central Cytogenetic Register, all cytogenetic laboratories in DK, paediatric departments throughout the country. The Medical Birth Register and The Register of Causes of Death in DK. Nineteen liveborn probands with trisomy 13 and 76 liveborn probands with trisomy 18 were found. No stillborn cases with trisomy 13 but 6 with trisomy 18 were found. By prenatal diagnosis 19 probands with trisomy 13 and 46 with trisomy 18 were found. Based on liveborn and stillborn probands, the prevalence at birth was 1 per 29,374 for trisomy 13 and 1 per 6806 for trisomy 18. The median survival for trisomy 13 was 2.5 days, while the same figure for trisomy 18 was 6.0 days. The rates calculated seem rather low compared to earlier studies.     

The impact of cardiac surgery in patients with trisomy 18 and trisomy 13 in Japan

Congenital heart defects (CHD) are very common in patients with trisomy 18 (T18) and trisomy 13 (T13). The surgical indication of CHD remains controversial since the natural history of these trisomies is documented to be poor. To investigate the outcome of CHD in patients with T18 and T13, we collected and evaluated clinical data from 134 patients with T18 and 27 patients with T13 through nationwide network of Japanese Society of Pediatric Cardiology and Cardiac Surgery. In patients with T18, 23 (17%) of 134 were alive at this survey. One hundred twenty-six (94%) of 134 patients had CHDs. The most common CHD was ventricular septal defect (VSD, 59%). Sixty-five (52%) of 126 patients with CHD developed pulmonary hypertension (PH). Thirty-two (25%) of 126 patients with CHD underwent cardiac surgery and 18 patients (56%) have survived beyond postoperative period. While palliative surgery was performed in most patients, six cases (19%) underwent intracardiac repair for VSD. Operated patients survived longer than those who did not have surgery (P < 0.01). In patients with T13, 5 (19%) of 27 patients were alive during study period. Twenty-three (85%) of 27 patients had CHD and 13 (57%) of 27 patients had PH. Atrial septal defect was the most common form of CHD (22%). Cardiac surgery was done in 6 (26%) of 23 patients. In this study, approximately a quarter of patients underwent surgery for CHD in both trisomies. Cardiac surgery may improve survival in selected patients with T18.     

Three cell line mosaicism involving structural and numerical abnormalities of chromosome 18 in a 3.5‐Year‐old girl: 47,XX,+18/47,XX,+del(18)(q22)/46,XX

We report on a 3.5‐year‐old girl with a mosaic karyotype including full trisomy 18, normal cells and a majority of cells with partial trisomy involving an extra chromosome 18 deleted at band q22. She had cardiac and CNS anomalies, dysmorphic facial features failure to thrive and developmental delay. A gastrostomy tube was placed at 2 years of age. The combination of improved nutrition and optimal developmental therapy has led to her sitting supported, attempting to stand and enhancement of her cognitive and non‐verbal communication abilities. Molecular investigation of the patient and her parents using microsatellite analysis has led to the conclusion that, as expected, the additional copy of chromosome 18 constituting the full trisomic cell line is maternal meiosis I in origin. The data, however, indicate that in the trisomic cell line containing the deleted chromosome 18q, the structurally abnormal 18 was of paternal origin. We think this case is the first described with both structural and numerical trisomic mosaicism involving chromosome 18 in a liveborn infant. We propose a mechanism of origin and review the literature, comparing the clinical presentation of this case with individuals having full or partial trisomy 18. © 2001 Wiley‐Liss, Inc.     

18号染色体三体NMRI小鼠发育畸形的实验研究

目的 通过对１８三体在ＮＭＲＩ小鼠发生率的研究及１８三体胚鼠和正常胚鼠的大体形态学对照观察，进一步认识１８三体ＮＭＲＩ小鼠的生长发育畸开。方法 ６０只Ｈａｎ－ＮＭＲＩ母鼠及１１只具有Ｒｂ（２．１８）６Ｒｍａ／Ｒｂ（１．１８）１０Ｒｍａ染色体结构的雄鼠，分别在妊娠第１６和１７天随机分两组断颈处死母鼠，６０只母鼠共有８２３只子代胚胎着床，其中５６９只为活胚。并对所获得的子代活胚进行染色体分体和大体莆态     

Trisomy 18/trisomy 13 mosaicism in an adult with profound mental retardation and multiple malformations

We report on an adult woman with profound mental retardation and multiple anomalies who consists of 3 cell lines: one with trisomy 18, one with trisomy 13, and a normal cell line. Her phenotype includes manifestations of both trisomy syndromes. The origin of these cell lines could have been a doubly aneuploid (48,XX+ 13, + 18) or singly aneuploid (47,XX + 18 or 47,XX, + 13) zygote with subsequent mitotic nondisjunctions, or a normal zygote with multiple mitotic nondisjunctions. There have been four previous reports of mosaicism involving both trisomy D and trisomy E; all died in the first six months of life. Two of these cases had a doubly aneuploid (48,XX, + D + E) cell line. Our patient illustrates the need for study of several tissues in patients with complex aneuploidy syndromes or atypical manifestations of a given syndrome (such as prolonged survival), as well as the need for caution in counseling families about prognosis for survival in autosomal trisomies which usually are lethal.     

Twenty-year trends in the prevalence of Down syndrome and other trisomies in Europe: impact of maternal age and prenatal screening

This study examines trends and geographical differences in total and live birth prevalence of trisomies 21, 18 and 13 with regard to increasing maternal age and prenatal diagnosis in Europe. Twenty-one population-based EUROCAT registries covering 6.1 million births between 1990 and 2009 participated. Trisomy cases included live births, fetal deaths from 20 weeks gestational age and terminations of pregnancy for fetal anomaly. We present correction to 20 weeks gestational age (ie, correcting early terminations for the probability of fetal survival to 20 weeks) to allow for artefactual screening-related differences in total prevalence. Poisson regression was used. The proportion of births in the population to mothers aged 35+ years in the participating registries increased from 13% in 1990 to 19% in 2009. Total prevalence per 10 000 births was 22.0 (95% CI 21.7–22.4) for trisomy 21, 5.0 (95% CI 4.8–5.1) for trisomy 18 and 2.0 (95% CI 1.9–2.2) for trisomy 13; live birth prevalence was 11.2 (95% CI 10.9–11.5) for trisomy 21, 1.04 (95% CI 0.96–1.12) for trisomy 18 and 0.48 (95% CI 0.43–0.54) for trisomy 13. There was an increase in total and total corrected prevalence of all three trisomies over time, mainly explained by increasing maternal age. Live birth prevalence remained stable over time. For trisomy 21, there was a three-fold variation in live birth prevalence between countries. The rise in maternal age has led to an increase in the number of trisomy-affected pregnancies in Europe. Live birth prevalence has remained stable overall. Differences in prenatal screening and termination between countries lead to wide variation in live birth prevalence.     

An examination of the spectrum of anatomic defects and variations found in eight cases of trisomy 13

We report the anatomic variations found in four additional cases of trisomy 13. Data from these and four previous cases [Colacino and Pettersen, 1978] are utilized to define a muscle phenotype. Previously unreported defects include the bilateral presence of cervical ribs and the bilateral absence of 12th thoracic ribs in five of the eight cases. One unusual developmental defect of the great vessels is also described. The findings suggest that a definitive diagnosis of trisomy 13 can be made on the basis of six muscle variations.     

Tertiary trisomy due to a reciprocal translocation of chromosomes 5 and 21 in a four‐generation family

Tertiary trisomy, or double trisomy, is a rare occurrence. We present two individuals with a previously unreported tertiary trisomy for chromosomes 5p and 21q in an eight‐generation pedigree. Their phenotypes are compared with other partial trisomies of either 5p or 21q from the literature. The propositus was diagnosed with trisomy 21 at 2 years of age after a karyotype study for short stature and developmental delay. His phenotype was described as atypical for Down syndrome. He presented at 9 years of age because of pervasive behavioral problems and obesity. He was brachycephalic with a flattened nasal bridge, but he lacked other characteristics of trisomy 21. Because of lack of phenotypic evidence of Down syndrome, a repeat karyotype was obtained and showed 47,XY,+der(21)t(5;21)(p15.1; q22.1), incorporating partial trisomies of both chromosomes 5 and 21. Mother had a balanced translocation, 46,XX,t(5;21)(p15.1; q22.1); 8 other relatives were examined. The translocation originated from the maternal great‐grandmother, but only the propositus and his mentally retarded aunt had a similar phenotye and the derivative chromosome. Fluorescence in situ hybridization showed absence of band 21q22.2 in the derivative chromosome of the propositus and his aunt, indicating that neither had trisomy for the Down syndrome critical region. These cases represent a unique double partial trisomy of chromosome arms 5p and 21q that occurred because of 3:1 malsegregation of a reciprocal translocation. These cases further demonstrate that phenotypic discordance with cytogenetic results dictate further investigation using advanced cytogenetic hybridization. Am. J. Med. Genet. 92:311–317, 2000. © 2000 Wiley‐Liss, Inc.     

Experiences of children with trisomy 18 referred to pediatric palliative care services on two continents

Children with trisomy 18 that survive beyond the neonatal period have multiple congenital anomalies, neurodevelopmental disability, and high mortality rates. The experience of children with trisomy 18 who receive pediatric palliative care services is largely unknown. We conducted a retrospective review of children with trisomy 18 receiving pediatric palliative care services at both Boston Children's Hospital, USA and Great Ormond Street Hospital, UK from January 1, 2004 to January 1, 2015. Fifty‐eight children with trisomy 18 were referred to pediatric palliative care, 38 in the United Kingdom, 20 in the United States. Median age at referral was 19 days (2–89) in the United Kingdom, and 25 days (1–463) in the United States. Median length of time being followed by pediatric palliative care was 32 days (1–1,637) in the United Kingdom and 67 days (3–2,442) in the United States. The only significant difference in the two cohorts (p = .001) was in likelihood of receiving cardiac surgical intervention—37% in the United States, 0% the United Kingdom. Children with trisomy 18 receive pediatric palliative care services, with variable age at referral and for a variable length of time. Further research is needed to understand the experience of children with trisomy 18 and their families receiving pediatric palliative care services.     

Partial 18q trisomy and 18p monosomy resulting from a maternal pericentric inversion,inv(18)(p11.2q21.3)

A 7-year-old boy with dysmorphic features was found to have a recombinant chromosome 18, rec(18), resulting from meiotic recombination of a maternal pericentric inversion, inv(18) (p11.2q21.3), as defined by high-resolution banding. He was trisomic for the long arm (q21.3-qter) and monosomic for the short arm (p11.2-pter) of chromosome 18. His clinical features were compared with those in other rec(18) cases, and also those in monosomy 18p, trisomy 18qter and full trisomy 18 syndromes. The risk of recombinant formation for inv(18) carriers was also discussed.     

Survival in trisomy 18

Prenatal diagnosis of trisomy 18 by amniocentesis in the latter half of pregnancy is now a common event. Accurate prognostic information is crucial for families making decisions about delivery management. Three recently published studies showed much shorter survival for trisomy 18 than was reported by earlier papers. For this reason, we studied trisomy 18 survival. We examined chromosome laboratory records to find all trisomy 18 diagnoses made in Utah between 1979 and 1988. Death certificates and hospital records were used to determine survival. We found 64 live-born cases with trisomy 18 out of 388,563 total births over the 10-year period, a prevalence of 1/6071. Our results show a median survival of 4 days and a 1 week survival of 45%, similar to that reported in the 3 recent studies. However, we had a significantly greater survival at 6 months (9% in Utah versus 3% in Denmark) and 1 year (5% versus 0 in the 3 studies). In contrast to recent studies, earlier investigations showed 80% survival at 2 weeks and 8% at 1 year. It is not surprising that recent studies show shorter survival, since in the 1960s the diagnosis was typically not made until age 2 months. With prenatal and neonatal diagnosis many cases which would have died prior to detection in earlier times are now diagnosed. The longer survival discrepancies are more difficult to explain, but may simply be due to small numbers. © 1994 Wiley-Liss, Inc.     

Presenting physical characteristics, medical conditions, and developmental status of long-term survivors with trisomy 9 mosaicism

Much of the available literature on individuals with trisomy 9 mosaicism focuses on reports concerning results of prenatal testing or fetal autopsy with limited reports of long-term survivors. Data from the Tracking Rare Incidence Syndromes (TRIS) project offer the largest series to date examining the presenting physical characteristics and medical conditions at birth for 14 individuals. Results indicated the presence of low set ears and microcephaly for some children in the sample. Cardiac anomalies were reported along with feeding and respiratory difficulties in the immediate postnatal period. In addition, developmental status data indicated a wide range in functioning level with examples of demonstrated skills provided. Implications for professionals caring for patients with trisomy 9 mosaicism are offered.     

Seizures in trisomy 18: Prevalence,description, and treatment

Changes in medical intervention over the last decade have improved outcomes for individuals with trisomy 18, the second most common human aneuploidy syndrome at birth. As children with trisomy 18 live longer, a shared concern of medical experts and parents is the occurrence and treatment of seizures. Previously published surveillance guidelines for this condition have not addressed seizure management. Using parent-reported data collected as part of the Tracking Rare Incidence Syndromes project, we report on the prevalence, course, and management of seizures in individuals with trisomy 18. Twenty-eight percent (52/186) of individuals diagnosed with trisomy 18 in our retrospective cohort experienced generalized, focal, or mixed seizures at some point in their lifetime. For many individuals, seizures were effectively managed by broad-spectrum anti-seizure medications. Correlation analysis showed that focal and generalized seizures were more likely to occur in individuals who had previously experienced infantile spasms or central apnea. Electroencephalogram testing should be considered as part of a standard screening approach in individuals with trisomy 18 to enable early diagnosis and treatment of seizures. An international registry that incorporates parent-reported and clinical data for patients with trisomy 18 may facilitate ongoing research and recruitment into clinical trials for seizure management.     

Three cases of trisomy 13 mosaicism and a review of the literature

We describe three cases of trisomy 13 mosaicism and review the literature. The phenotype ranges from a severe form similar to Patau syndrome, through to physical and mental normality. This range presumably reflects the proportion and tissue distribution of the trisomic cell line. The percentage of trisomic cells in lymphocytes correlates poorly with the observed phenotype.     

Fibroblasts of two patients with trisomy 18 show 1.5-fold increase in peptidase A activity over normal human diploid fibroblasts

Peptidase A (Pep A) activity assigned to chromosome 18q23 was biochemically examined in fibroblasts cultured from two patients with trisomy 18 and in fibroblasts derived from normal individuals. The trisomy 18 fibroblasts showed approximately a 1.5-fold increase in Pep A activity over that of the control fibroblasts. Agar gel electrophoretic analysis revealed no detectable differences in the electrophoretic mobility and isoenzyme patterns of Pep A between the trisomy 18 fibroblasts and normal ones. The present results show the trisomy 18 fibroblasts to be suitable for study of the gene dosage effect of Pep A.     

Neural tube defects and omphalocele in trisomy 18

A trisomy 18 fetus with severe congenital anomalies including craniorachischisis, large omphalocele, and bilateral cleft lip and palate is reported. The occurrence of neural tube defects and/or omphalocele in reported cases of trisomy 18 is discussed and the frequency of these anomalies in 85 trisomy 18 patients evaluated at Indiana University School of Medicine from 1963 to 1986 is reviewed. In this series of patients the frequency of neural tube defects was 7.0% and the frequency of omphaloceles was 5.9%. The percentage of these findings in our cases supports the premise that neural tube defects and omphaloceles are part of the trisomy 18 phenotype. Since fetuses with trisomy 18 are subject to early fetal loss or premature birth, the more subtle physical features of this condition may not be apparent. Thus, karyotyping of fetuses and premature infants with either neural tube defect or omphalocele should be considered.