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

Underlying genetic etiologies of congenital diaphragmatic hernia

Congenital diaphragmatic hernia (CDH) is often detectable prenatally. Advances in genetic testing have made it possible to obtain a molecular diagnosis in many fetuses with CDH. Here, we review the aneuploidies, copy number variants (CNVs), and single genes that have been clearly associated with CDH. We suggest that array-based CNV analysis, with or without a chromosome analysis, is the optimal test for identifying chromosomal abnormalities and CNVs in fetuses with CDH. To identify causative sequence variants, whole exome sequencing (WES) is the most comprehensive strategy currently available. Whole genome sequencing (WGS) with CNV analysis has the potential to become the most efficient and effective means of identifying an underlying diagnosis but is not yet routinely available for prenatal diagnosis. We describe how to overcome and address the diagnostic and clinical uncertainty that may remain after genetic testing, and review how a molecular diagnosis may impact recurrence risk estimations, mortality rates, and the availability and outcomes of fetal therapy. We conclude that after the prenatal detection of CDH, patients should be counseled about the possible genetic causes of the CDH, and the genetic testing modalities available to them, in accordance with generally accepted guidelines for pretest counseling in the prenatal setting.

Congenital diaphragmatic hernia in 22q11.2 deletion syndrome

We report the important association of congenital diaphragmatic hernia (CDH) and 22q11.2 deletion syndrome (22q11.2DS). The prevalence of CDH in our cohort of patients with 22q11.2DS is 0.8% (10/1246), which is greater than in the general population (0.025%). This observation suggests that 22q11.2DS should be considered when a child or fetus presents with CDH, in particular when other clinical findings associated with the 22q11.2DS are present, such as congenital cardiac defects. Furthermore, this finding may lead to the identification of an additional locus for diaphragmatic hernia in the general population. © 2016 Wiley Periodicals, Inc.

Prenatal diagnosis and array comparative genomic hybridization characterization of trisomy 21 in a fetus associated with right congenital diaphragmatic hernia and a review of the literature of chromosomal abnormalities associated with congenital diaphragmatic hernia

OBJECTIVE

Rapid genome-wide aneuploidy diagnosis using uncultured amniocytes and array comparative genomic hybridization (aCGH) is useful in pregnancy with abnormal ultrasound findings. The purpose of this report is to report a case of right congenital diaphragmatic hernia (CDH) associated with trisomy 21 diagnosed prenatally by aCGH and to review the literature of chromosomal abnormalities associated with CDH.

CASE REPORT

A 29-year-old woman was referred for genetic counseling at 25 weeks of gestation because of fetal CDH. The pregnancy was uneventful until 25 weeks of gestation when level II ultrasound detected isolated right CDH. Ultrasound showed that the liver and gallbladder were located in the right hemithorax, and there was levocardia. Fetal magnetic resonance imaging confirmed the diagnosis of right CDH with the gallbladder and part of the liver appearing in the right hemithorax and the heart shifting to the left hemithorax. Amniocentesis was immediately performed. About 10 mL of amniotic fluid was sent for aCGH analysis by use of the DNA extracted from uncultured amniocytes, and 20 mL of amniotic fluid was sent for conventional cytogenetic analysis. aCGH analysis revealed the result of arr 21p11.2q22.3 (9,962,872-48,129,895) × 3, consistent with the diagnosis of trisomy 21. Conventional cytogenetics revealed a karyotype of 47,XY,+21. Postnatally, polymorphic DNA marker analysis using DNAs extracted from the placenta and parental bloods showed a heterozygous extra chromosome 21 of maternal origin consistent with the result of maternal meiosis I nondisjunction.

CONCLUSION

Prenatal diagnosis of right CDH should raise a suspicion of chromosomal abnormalities especially trisomy 21 and the association of Morgagni hernia.

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.

Genetic aspects of human congenital diaphragmatic hernia

Congenital diaphragmatic hernia (CDH) is a common major malformation affecting 1/3000-1/4000 births, which continues to be associated with significant perinatal mortality. Much current research is focused on elucidating the genetics and pathophysiology contributing to CDH to develop more effective therapies. The latest data suggest that many cases of CDH are genetically determined and also indicate that CDH is etiologically heterogeneous. The present review will provide a brief summary of diaphragm development and model organism work most relevant to human CDH and will primarily describe important human phenotypes associated with CDH and also provide recommendations for diagnostic evaluation of a fetus or infant with CDH.

Overview of epidemiology, genetics, birth defects, and chromosome abnormalities associated with CDH

Congenital diaphragmatic hernia (CDH) is a common and well-studied birth defect. The etiology of most cases remains unknown but increasing evidence points to genetic causation. The data supporting genetic etiologies which are detailed below include the association of CDH with recurring chromosome abnormalities, the existence of CDH-multiplex families, and the co-occurrence of CDH with additional congenital malformations.

Genetic factors in congenital diaphragmatic hernia

Congenital diaphragmatic hernia (CDH) is a relatively common birth defect associated with high mortality and morbidity. Although the exact etiology of most cases of CDH remains unknown, there is a growing body of evidence that genetic factors play an important role in the development of CDH. In this review, we examine key findings that are likely to form the basis for future research in this field. Specific topics include a short overview of normal and abnormal diaphragm development, a discussion of syndromic forms of CDH, a detailed review of chromosomal regions recurrently altered in CDH, a description of the retinoid hypothesis of CDH, and evidence of the roles of specific genes in the development of CDH.

Fryns syndrome: A review of the phenotype and diagnostic guidelines

Fryns syndrome (FS) is the commonest autosomal recessive syndrome associated with congenital diaphragmatic hernia (CDH) and comprises CDH, pulmonary hypoplasia, craniofacial anomalies, distal limb hypoplasia, and internal malformations. Although there have been more than 50 case reports on probands with FS, the diagnostic guidelines were formulated from a review of eight patients and modifications to the guidelines have only once been suggested. Recently, several case reports have described new anomalies in FS and other papers have highlighted the variation in expressivity found in FS. This paper examines the medical literature on FS to define the phenotype and to review the diagnostic guidelines. We conclude that CDH with brachytelephalangy and/or nail hypoplasia is strongly suggestive of the diagnosis and that pulmonary hypoplasia, craniofacial dysmorphism, orofacial clefting, and polyhydramnios are sufficiently frequent to be diagnostically useful. Other distinctive malformations that are consistent with FS include ventricular dilatation or hydrocephalus, agenesis of the corpus callosum, neuronal or cerebellar heterotopias, abnormalities of the aorta, renal cysts, dilatation of the ureters, bicornuate uterus, renal dysplasia, proximal thumbs, and broad clavicles.

Second-trimester sonographic findings in trisomy 22: report of 3 cases and review of the literature

OBJECTIVE

To describe cases of trisomy 22 detected prenatally on second-trimester sonography and to review the literature on similar cases, with special emphasis on the prenatal findings and pregnancy outcome.

METHODS

We performed follow-up second-trimester sonography and fetal karyotyping on 3 pregnant women who were referred because of abnormal findings on initial second-trimester scans. We also conducted a literature search for other reports of sonographic findings in trisomy 22.

RESULTS

Fetal abnormalities shown on sonography included nuchal thickening, mild generalized skin edema, an atrioventricular septal defect, an interventricular septal defect, edema of the scalp, face, and neck, severe left pleural effusion with a marked mediastinal shift, ascites, agenesis of the diaphragm, ambiguous genitalia, a single umbilical artery, bradycardia, a multicystic left kidney, and an absent right kidney. All 3 fetuses had karyotypes indicating trisomy 22. One pregnancy was terminated at the parents' request, and 2 ended in fetal death at 23 and 26 weeks. Our literature search revealed only 1 previous report of second-trimester sonographic diagnosis of trisomy 22. We found 3 other reports describing prenatal diagnosis in the third trimester, but only limited information on the sonographic findings was available.

CONCLUSIONS

Second-trimester sonography provides valuable clues for the prenatal diagnosis of several chromosomal disorders, including trisomy 22. Prenatal karyotyping is warranted if fetal growth restriction is detected in the second trimester, especially if associated with congenital defects.

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.

Congenital diaphragmatic hernia in a family segregating a reciprocal translocation t(5;15)(p15.3;q24)

Congenital diaphragmatic hernia (CDH) is a relatively common malformation of unknown cause with high mortality due to hypoplasia of the lungs and pulmonary hypertension. We studied a family in which two fetuses had CDH, and two pregnancies resulted in first trimester missed abortions. Both fetuses with CDH had an apparently normal karyotype. In a subsequent pregnancy, fluorescent in situ hybridization analysis of amniocytes showed a balanced translocation 46,XY, t(5;15) (p15.3;q24) also present in the mother and in a normal child, suggesting that the diaphragmatic hernia in the first two fetuses was caused by a cryptic unbalanced translocation. This hypothesis is supported by a previous observation of CDH in a distal deletion of 15q as part of a multiple congenital anomalies syndrome. It is suggested that a gene distal to 15q21 is important for the normal development of the diaphragm.

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.

Recurrence of diaphragmatic agenesis associated with multiple midline defects: evidence for an autosomal gene regulating the midline

We report the familial occurrence of diaphragmatic agenesis in association with other midline anomalies in a brother and sister. Opitz and Gilbert [Am J Med Genet 1982, 12:443-455] introduced the concept of the midline as a developmental field, and there have been reports of pedigrees compatible with the hypothesis of an X-linked gene regulating the development of the midline. This family suggests that an autosomal gene also contributes to the morphogenesis of midline structures.

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.