Trisomy 22 in a liveborn infant with multiple congenital anomalies

Non-mosaic trisomy 22 and congenital heart surgery using the shared decision making model: a case report

BACKGROUND

Liveborn infants with non-mosaic trisomy 22 are rarely described in the medical literature. Reported lifespan of these patients ranges from minutes to 3 years, with the absence of cardiac anomalies associated with longer-term survival. The landscape for offering cardiac surgery to patients with rare autosomal trisomies is currently evolving, as has been demonstrated recently in trisomies 13 and 18. However, limited available data on patients with rare autosomal trisomies provides a significant challenge in perinatal counseling, especially when there are options for surgical intervention.

CASE PRESENTATION

In this case report, we describe an infant born at term with prenatally diagnosed apparently non-mosaic trisomy 22 and multiple cardiac anomalies, including a double outlet right ventricle, hypoplastic aortic valve and severe aortic arch hypoplasia, who underwent cardiac surgery. The decisions made by her family lending to her progress and survival to this day were made with a focus on the shared decision making model and support in the prenatal and perinatal period. We also review the published data on survival and quality of life after cardiac surgery in infants with rare trisomies.

CONCLUSIONS

This patient is the only known case of apparently non-mosaic trisomy 22 in the literature who has undergone cardiac surgery with significant survival benefit. This case highlights the impact of using a shared decision making model when there is prognostic uncertainty.

Congenital heart defects associated with aneuploidy syndromes: New insights into familiar associations

The frequent occurrence of congenital heart defects (CHDs) in chromosome abnormality syndromes is well-known, and among aneuploidy syndromes, distinctive patterns have been delineated. We update the type and frequency of CHDs in the aneuploidy syndromes involving trisomy 13, 18, 21, and 22, and in several sex chromosome abnormalities (Turner syndrome, trisomy X, Klinefelter syndrome, 47,XYY, and 48,XXYY). We also discuss the impact of noninvasive prenatal screening (mainly, cell-free DNA analysis), critical CHD screening, and the growth of parental advocacy on their surgical management and natural history. We encourage clinicians to view the cardiac diagnosis as a "phenotype" which supplements the external dysmorphology examination. When detected prenatally, severe CHDs may influence decision-making, and postnatally, they are often the major determinants of survival. This review should be useful to geneticists, cardiologists, neonatologists, perinatal specialists, other pediatric specialists, and general pediatricians. As patients survive (and thrive) into adulthood, internists and related adult specialists will also need to be informed about their natural history and management.

Antenatal Detection of Trisomy 22

Trisomy 22 (47, XX, +22), a rare chromosomal defect, was detected antenatally by chromosome analysis of the amniotic fluid after an obstetric ultrasound examination revealed multiple anomalies. The ultrasound findings included intrauterine growth retardation, holoprosencephaly, cleft lip, cardiac anomalies, decreased amniotic fluid level, and an abnormally thickened nuchal fold. Postnatal examination and autopsy confirmed the ultrasound findings.

Live-born trisomy 22: patient report and review

Trisomy 22 is a common trisomy in spontaneous abortions. In contrast, live-born trisomy 22 is rarely seen due to severe organ malformations associated with this condition. Here, we report on a male infant with complete, non-mosaic trisomy 22 born at 35 + 5 weeks via caesarean section. Peripheral blood lymphocytes and fibroblasts showed an additional chromosome 22 in all metaphases analyzed (47,XY,+22). In addition, array CGH confirmed complete trisomy 22. The patient's clinical features included dolichocephalus, hypertelorism, flattened nasal bridge, dysplastic ears with preauricular sinuses and tags, medial cleft palate, anal atresia, and coronary hypospadias with scrotum bipartitum. Essential treatment was implemented in close coordination with the parents. The child died 29 days after birth due to respiratory insufficiency and deterioration of renal function. Our patient's history complements other reports illustrating that children with complete trisomy 22 may survive until birth and beyond.

Complex cardiac defect, bowing of lower limbs and multiple anomalies in trisomy 22. Ultrasound, post-mortem CT findings with necropsy confirmation

Trisomy 22 is commonly associated with severe intrauterine growth retardation and congenital anomalies. The sonographic identification of a complex cardiac defect and bowing of the long bones associated with multiple structural anomalies add new clinical informations to our knowledge about the prenatal phenotype of trisomy 22. These findings have not been reported previously and are of critical importance as sonographic signs of trisomy 22 may overlap that of trisomy 13-18 and will help clinicians in indicating fetal karyotyping. Prenatal diagnosis of trisomy 22 is essential as trisomy 22 is a lethal condition.

Non-mosaic trisomy 22: a report of 2 cases

Non-mosaic trisomy 22 is a common cause of first trimester miscarriage and has a livebirth incidence of 1 in 30,000-50,000. Consequently there is a paucity of information for counselling parents. Detection in the second trimester is rare. It is commonly associated with severe growth retardation and multiple structural abnormalities. Oligohydramnios is frequently seen and can make detection of other abnormalities difficult. The outlook is uniformly poor and survival beyond the first trimester may present management dilemmas. A thorough fetal assessment including high-resolution cytogenetics with or without FISH is required for counselling. Careful plans for intrapartum and neonatal management may be necessary. The recurrence risk is thought to be low but information is very limited as there have been no reported cases of recurrence. We present two case of non-mosaic trisomy 22 including the first to be diagnosed subsequent to investigation for a high serum screening Down's risk.

Unexpected survival in a case of prenatally diagnosed non-mosaic trisomy 22: Clinical report and review of the natural history

Over 30 cases of complete non-mosaic trisomy 22 have been reported in the literature in the last 20 years [Crowe et al., 1997: Am J Med Genet 71:406-413]. Twenty-two infants were liveborn with an average life expectancy of four days. Of these, nine survived beyond the first two weeks of life. The life span ranged from minutes to 3 years of age. We report a case of an infant diagnosed prenatally with complete non-mosaic trisomy 22. Options such as aggressive medical/surgical intervention or limiting interventions to symptomatic care including home hospice were discussed openly. Given this information, the family elected to provide minimal supportive measures with pediatric hospice. The infant lived for 2 months with her family before her death. Numerous medical and surgical complications are associated with this disorder. Both the family and the medical team must be prepared for in utero fetal demise, stillbirth, or for limited life expectancy. Proper management, therefore, depends upon an understanding of the diagnosis.

Temporal bone morphometric study on the eustachian tube and its associated structures in patients with chromosomal aberrations

This study characterized phenotypic anomalies of the eustachian tube (ET) and its associated structures in individuals with various chromosomal aberrations (trisomies 13, 18, 21, and 22 and inversion of chromosome 1). The morphological characteristics of the ET and its accessory structures from 10 temporal bone-ET specimens, obtained from 10 individuals with chromosomal aberrations who ranged from the 26th gestational week to 1 year in age, were compared with the same structures from 21 age-matched control subjects without anomalies. The subjects with chromosomal aberrations had a significantly smaller volume of the lateral lamina (LL) of the ET cartilage, a reduced attachment of the tensor veli palatini muscle (TVPM), and, in some cases, a reduced volume of the lumen of the cartilaginous ET. The volume of the medial lamina (ML) of the ET cartilage was normal at birth, but smaller in specimens more than 2 months of age; this finding suggests that the prenatal development was normal, but that the postnatal growth was retarded. The subjects with chromosomal aberrations also displayed a smaller ratio of the volume of the LL to that of the ML (LL/ML ratio). Our results suggest that individuals with various chromosomal aberrations have rather similar anomalies of the ET and its associated structures. We speculate that these anomalies might be closely related to ET dysfunction in these patients.

Histopathological study on temporal bone and eustachian tube in trisomy 22

Two temporal bone-eustachian tube (ET) specimens, one from a 34-gestational week-old male newborn and the other from a 3-month-old female infant, both with trisomy 22, were studied histopathologically. Both cases demonstrated severe inner-ear anomalies including hypoplastic cochlea, atrophy of the saccular macula, and dislocated endolymphatic sac and vestibular aqueduct. In addition, they had several anomalies in the ET including widely developed medial lamina of the ET cartilage, undeveloped lateral lamina of the ET cartilage, and absence of attachment of the tensor veli palatini muscle to the ET cartilage. We discuss the implications of the observed anomalies with regard to developmental and clinical issues.

Fryns syndrome phenotype and trisomy 22

Trisomy 22 was detected in a 32-week-old fetus born to an overweight mother with hypertension. Severe intrauterine growth retardation was associated with phenotypic manifestations of Fryns syndrome: diaphragmatic hernia, facial defects, and nail hypoplasia with short distal fifth phalanges. This is the second report of congenital diaphragmatic hernia in trisomy 22. This case demonstrates the importance of karyotyping malformed fetuses or newborns, even if a nonchromosome syndrome seems identifiable on clinical grounds. To date, at least 10 cases of Fryns syndrome have been reported without chromosome analysis.

Clinical and molecular studies in full trisomy 22: further delineation of the phenotype and review of the literature

Trisomy 22 is commonly found among spontaneous abortions, second in frequency of occurrence only to trisomy 16. Most earlier reports of surviving trisomy 22 cases in the literature are thought to represent the product of unbalanced 11;22 translocations or the result of undetected mosaicism, since this condition is thought to manifest early embryonic or fetal lethality. We present two strikingly similar cases of non-mosaic trisomy 22 surviving to late gestation. In this paper we emphasize the unique phenotype of this trisomy which included intrauterine growth retardation, microcephaly, broad flat nasal bridge with epicanthal folds and ocular hypertelorism, microtia, variable cleft palate, webbed neck, congenital heart defects involving anomalous great vessels, anorectal and renal anomalies, and hypoplastic distal digits with thumb anomalies. We also explore why some cases survive to late gestation. Confined placental mosaicism, a frequent finding in other lethal trisomies, has been ruled out in one of the cases. Molecular studies done to assess the parental origin of the extra chromosome in the other case showed that the non-disjunction originated during maternal meiosis II. Parental origin of the extra chromosome does not seem to play a role in late survival for trisomy 22.

De novo tandem duplication of chromosome segment 22q11-q12: clinical, cytogenetic, and molecular characterization

We report on a case of duplication of the segment 22q11-q12 due to a de novo duplication. Molecular cytogenetics studies demonstrated this to be a tandem duplication, flanked proximally by the marker D22Z4, a centromeric alpha satellite DNA repeat, and distally by D22S260, an anonymous DNA marker proximal to the Ewing sarcoma breakpoint. The segment includes the regions responsible for the "cat-eye," Di George, and velo-cardio-facial syndromes and extends distal to the breakpoint cluster region (BCR). The clinical picture is dominated by the cardiac defects and includes findings reminiscent of "cat-eye" syndrome. These findings reinforce the hypothesis that the proximal 22q region contains dosage-sensitive genes involved in development.

Hydrocephalus in an infant with trisomy 22

We present an infant with true trisomy 22. Mosaicism is ruled out by the finding of a 47,XX, +22 karyotype in all cells analysed originating from two embryonic germ layers. The physical findings are consistent with the previously noted features including developmental delay, ear abnormalities, micrognathia, clefting, and congenital heart disease. The patient is the first described with macrocephaly and hydrocephalus and the second with holoprosencephaly.

Confirmation of trisomy 22 in two cases using chromosome painting: comparison with t(11;22)

We present a nonmosaic case of trisomy 22 in a liveborn, abnormal infant and a second case of a fetus who died in utero. Both have been verified cytogenetically and confirmed by in situ hybridisation with a centromeric alphoid probe and chromosome painting. The accuracy of the combined cytogenetic and molecular cytogenetic approaches in the karyotype determination is highlighted by comparison with a case showing partial translocation of chromosome 22 in t(11;22) (q23;q11).

Trisomy 22 confirmed by fluorescent in situ hybridization

We report on a newborn girl with multiple congenital anomalies, whose G-banded chromosome analysis showed complete trisomy 22. Chromosome painting using a whole-chromosome painting probe for chromosome 22 confirmed that neither chromosome 22 was involved in a cryptic translocation.

Trisomy 22 with congenital diaphragmatic hernia and absence of corpus callosum in a liveborn premature infant

We report on a liveborn premature male with trisomy 22 who had multiple congenital anomalies, including congenital diaphragmatic hernia and absence of corpus callosum. He died of pulmonary hypoplasia associated with diaphragmatic hernia within 12 hours of age. Chromosome analysis by multiple banding techniques based on lymphocyte culture confirmed that he had trisomy 22. This may be the first report of congenital diaphragmatic hernia and isolated absence of corpus callosum associated with trisomy 22.

Unbalanced translocation 46,XY,-15,+der(22)t(15;22)(q13;q11)pat: case report and review of the literature

We present a boy with a rare unbalanced translocation 46,XY,-15,+der(22),t(15;22)(q13;q11) pat. Previous reports of similar chromosome findings mention only the Prader-Willi phenotype. At birth, his manifestations included severe hypotonia and lethargy, (typical of deletion of 15pter----q13); hypertelorism, down-slanting small palpebral fissures, preauricular tags, long philtrum (typical of duplication of 22pter----q11); severe laryngotracheomalacia, and proximal implantation of the thumb. In a review of the literature on chromosome abnormalities involving duplication of 22q11 the associated clinical phenotype consists of mild mental retardation, microcephaly, hypotonia, hypertelorism, down-slanting palpebral fissures, a long philtrum, cleft or highly arched palate, and ear abnormalities. Preauricular pits or tags are common. Cardiovascular defects, renal and genital problems and dislocated hips are frequently present. Anal atresia and colobomata are mainly seen in cat-eye syndrome, the phenotype associated with idic 22q11. Our findings indicate that patients with unbalanced t(15;22) can have manifestations of the dup 22q11, in addition to the previously reported Prader-Willi phenotype, even if the duplicated segment is small.

Proposed guidelines for diagnosis of chromosome mosaicism in amniocytes based on data derived from chromosome mosaicism and pseudomosaicism studies

Currently, accepted protocol which has been developed at the Prenatal Diagnosis Laboratory of New York City (PDL) requires that when a chromosome abnormality is found in one or more cells in one flask, another 20-40 cells must be examined from one or two additional flasks. Chromosome mosaicism is diagnosed only when an identical abnormality is detected in cells from two or more flasks. In a recent PDL series of 12,000 cases studied according to this protocol, we diagnosed 801 cases (6.68 per cent) of single-cell pseudomosaicism (SCPM), 126 cases (1.05 per cent) of multiple-cell pseudomosaicism (MCPM), and 24 cases (0.2 per cent) of true mosaicism. Pseudomosaicism (PM) involving a structural abnormality was a frequent finding (2/3 of SCPM and 3/5 of MCPM), with an unbalanced structural abnormality in 55 per cent of SCPM and 24 per cent of MCPM. We also reviewed all true mosaic cases (a total of 50) diagnosed in the first 22,000 PDL cases. Of these 50 cases, 23 were sex chromosome mosaics and 27 had autosomal mosaicism; 48 cases had numerical abnormalities and two had structural abnormalities. Twenty-five cases of mosaicism were diagnosed in the first 20 cells from two flasks, i.e., without additional work-up, whereas the other 25 cases required extensive work-up to establish a diagnosis (12 needed additional cell counts from the initial two culture flasks; 13 required harvesting a third flask for cell analysis). Our data plus review of other available data led us to conclude that rigorous efforts to diagnose true mosaicism have little impact in many instances, and therefore are not cost-effective. On the basis of all available data, a work-up for potential mosaicism involving a sex chromosome aneuploidy or structural abnormality should have less priority than a work-up for a common viable autosomal trisomy. We recommend revised guidelines for dealing with (1) a numerical versus a structural abnormality and (2) an autosomal versus a sex chromosome numerical aneuploidy. Emphasis should be placed on autosomes known to be associated with phenotypic abnormalities. These new guidelines, which cover both flask and in situ methods, should result in more effective prenatal cytogenetic diagnosis and reduced patient anxiety.

Placental mosaicism in a case of 46,XY,-22,+t(22;22)(p11;q11) or i(22q) diagnosed at amniocentesis

46,XY,-22,+t(22;22)(p11;q11) or i(22q) was diagnosed in 15/15 cells from two cultures from the amniotic fluid culture of a 31-year-old patient whose fetus demonstrated cystic hygroma on ultrasound. Cytogenetic studies performed on fetal skin from the abortus revealed the same karyotype as that seen on amniocentesis, but the placenta demonstrated a 46,XY/46,XY,-22,+t(22;22) or i(22q) mosaicism, with 65 per cent of the cells being 46,XY. This case provides an example of placental mosaicism for a normal male karyotype, while the fetus demonstrated non-mosaic trisomy 22.