Cystic hygroma as an early first-trimester ultrasound marker for recurrent Fryns' syndrome

Genetic Burden and Outcome of Cystic Hygromas Detected Antenatally: Results of 93 Pregnancies from a Single Center in the Northern Region of Turkey

Objective:

Genetic burden, fetal malformations, and fetal outcomes of 93 fetuses with cystic hygroma (CH) are reported from a single center in Turkey.

Patients and Methods:

Pregnancies, having a diagnosis of fetal CH, detected between January 2010 and October 2016, were included in the study except fetuses having increased nuchal translucency. Fetal age/gender, maternal age, the age of pregnancy, types of fetal malformations, karyotype, and outcomes were evaluated.

Results:

The average gestational age was 16.2 weeks. Nearly 47% of the pregnancies had multiple congenital anomalies, of which 58% had a chromosomal anomaly. Chromosomal anomaly rate was 68.2% in patients with hydrops fetalis. Aneuploidies were major chromosomal defects. All trisomies were of regular type except one with Robertsonian translocation (46, XY, +13, rob[13;14][q10;q10]). Seventy-four percentage pregnancies were terminated due to either fetal/karyotype anomaly.

Conclusion:

Characteristics of fetal CH were similar in different ethnical backgrounds. Aneuploidy is the dominant chromosomal constitution of fetal CH. Little information was known about the genes involved. Gene dosage effect implies that fetal CH is a complex genetic situation involving multiple genes interactions. For proper genetic counseling, each fetus with CH should be karyotyped, and fetal ultrasound examination should be performed. In the case of normal chromosome set, application of aCGH should be considered.

Prenatal management, pregnancy and pediatric outcomes in fetuses with septated cystic hygroma

It has been reported that, compared with simple increased nuchal translucency, fetal cases with septated cystic hygroma (CH) are more likely to face perinatal handicaps. However, pediatric outcomes and proper prenatal counseling for this anomaly have not yet been truly defined. We performed this study to determine pregnancy and pediatric outcomes of fetuses with septated CH. We searched records for cases with septated CH and collected data for structural abnormalities, karyotype analysis, and pregnancy outcomes. Fetuses born with septated CH were also evaluated for their pediatric outcomes. Sixty-nine fetuses with septated CH were enrolled in the study. Results showed that chromosomal abnormalities were present in 28 fetuses (40.6%), and the most common aneuploidy was Turner syndrome (n=14, 20.3%); 16 (23.2%) of the remaining cases, in which aneuploidy was not found, had coexistent structural malformations; 25 (36.2%) cases had normal karyotype and morphology. The total number of live births and infants with unfavorable neurologic follow-up were 13 (18.8%) and 2 (2.9%), respectively. Septated CH is associated with poor perinatal outcomes; therefore, karyotype analysis and ultrasonographic anomaly screening should be performed as initial steps, and expectant management should be offered to couples with euploid fetuses that have normal morphology.

[Increased nuchal translucency with normal karyotype]

Nuchal translucency (NT) measurement in first trimester screening between 11 and 14 weeks' gestation has now been clearly identified as a marker for aneuploidies and in particular for trisomy 21. Even in the absence of aneuploidy increased fetal nuchal translucency has been shown to be a marker for fetal heart malformations and numerous other fetal defects and genetic syndromes when the measure is>or=95th centile which is around 3,5 mm for each gestational age. Fetuses with NT thickness above the 99th centile and normal karyotype have a high risk of adverse prenatal outcome and this increase in risk is exponential as the nuchal translucency measurement increases. However, among children born alive with normal ultrasound at 22 weeks of gestation, there was no significant association between NT thickness and development at 2 years as assessed by clinical examination and ASQ scores, when with a control population. Counselling should emphasize that when the karyotype is normal and no fetal structural malformation was missed prenatally following resolution of nuchal thickening, the prognosis is not impaired at the age of 2.

Cardiovascular malformations in Fryns syndrome: is there a pathogenic role for neural crest cells?

We performed a comprehensive literature and case report review to characterize the cardiovascular malformations (CVMs) associated with Fryns syndrome (OMIM #229850), a multiple congenital anomaly/mental retardation syndrome consisting of diaphragmatic defects, significant pulmonary hypoplasia, distinctive facial appearance, distal digital hypoplasia, and numerous other external and internal anomalies. A total of 112 patients meeting diagnostic guidelines for Fryns syndrome were identified, of whom 82 met narrowly defined criteria (Group I) and 30 met broader diagnostic criteria (Group II). Twelve patients reported as having Fryns syndrome with atypical features (Group III) were also analyzed. A CVM was reported in 51% (42 of 82) of Group I patients, most commonly an atrial or ventricular septal defect (VSD) (23 of 42, 55%). Conotruncal and aortic arch CVMs were common (11 of 42, 26%), but not significantly so compared to the general population of infants to age 1 year [Ferencz et al., 1997]. Recognizing that minor septal defects associated with congenital diaphragmatic hernia (CDH) may occur in response to altered hemodynamics (instead of being a bonafide CVM), we excluded four patients reported as having hemodynamically insignificant VSDs. Following these exclusions, conotruncal CVMs were found more commonly than in the general population (11 of 38, 29%, P < or = 0.025). In Group II, 9 of 30 (30%) had a CVM with no predominant type among the small number of cases reviewed. Among the atypical Fryns syndrome patients in Group III, half (6 of 12, 50%) had a CVM; most (4 of 6, 67%) were conotruncal, in particular, type B interrupted aortic arch (3 of 4). Patients with Fryns syndrome have a high rate of CVMs, warranting thorough cardiac evaluation including echocardiogram (fetal and/or postnatal) in all patients, similar to the evaluation for other patients with diaphragmatic hernia. The possible association between conotruncal CVMs and Fryns syndrome may provide additional support for an etiologic role of genes related to neural crest cell development in the pathogenesis of Fryns syndrome and hence, congenital diaphragmatic hernia.

Increased nuchal translucency with normal karyotype

Increased fetal nuchal translucency (NT) thickness between 11 and 14 weeks' gestation is a common phenotypic expression of chromosomal abnormalities, including trisomy 21. However, even in the absence of aneuploidy, nuchal thickening is clinically relevant because it is associated with an increase in adverse perinatal outcome caused by a variety of fetal malformations, dysplasias, deformations, dysruptions, and genetic syndromes. Once the presence of aneuploidy is ruled out, the risk of perinatal outcome dose not statistically increase until the nuchal translucency measurement reaches 3.5 mm or more (>99th percentile). This increase in risk occurs in an exponential fashion as the NT measurement increases. However, if the fetus survives until midgestation, and if a targeted ultrasound at 20 to 22 weeks fails to reveal any abnormalities, the risk of an adverse perinatal outcome and postnatal developmental delay is not statistically increased.

A case of Fryns syndrome without diaphragmatic hernia and review of the literature

We report on a child with Fryns syndrome who showed a characteristic coarse hirsute facial appearance, bilateral cleft lip and palate, cardiac and renal anomalies, dilated bowel and distal limb abnormalities. However, diaphragmatic hernia, which is considered a cardinal feature in this condition, was absent in our patient. The parents were consanguineous supporting autosomal recessive inheritance.

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.

Outcome of pregnancy in chromosomally normal fetuses with increased nuchal translucency in the first trimester

OBJECTIVES

To study the outcome of chromosomally normal pregnancies with increased nuchal translucency at the 10-14-week scan.

DESIGN

Retrospective study of 1320 chromosomally normal singleton pregnancies with nuchal translucency of > or = 3.5 mm. In addition to fetal karyotyping these patients were managed with follow-up scans at 14-16 and 20-22 weeks, specialist fetal echocardiography and in selected cases by infection screening and further genetic testing.

RESULTS

In the 1320 pregnancies there were 68 (5.15%) spontaneous abortions or intrauterine deaths, 18 (1.36%) neonatal and infant deaths and 154 (11.67%) terminations of pregnancy. In the 1080 (81.82%) survivors, 60 (5.56%) had abnormalities requiring medical or surgical treatment or leading to mental handicap. The chance of a livebirth with no defects in the group with nuchal translucency of 3.5-4.4 mm was 86%, for those with translucency of 4.5-5.4 mm it was 77%, for those with translucency of 5.5-6.4 mm it was 67%, and for those with translucency of > or = 6.5 mm it was 31%.

CONCLUSIONS

Increased fetal nuchal translucency is associated with chromosomal abnormalities, many fetal defects and genetic syndromes. In the majority of cases a series of antenatal investigations, including fetal karyotyping, detailed scans, fetal echocardiography, as well as genetic testing and infection screening, that can be completed by 20 weeks of gestation would distinguish between the pregnancies destined to result in adverse outcome and those leading to the delivery of infants without major defects.

First-trimester ultrasound

There has been an increase in the use of fetal ultrasound in the first trimester. This article reviews the published literature with emphasis on fetal nuchal translucency (NT). When measured according to well-defined guidelines, increased NT identifies about 80% of chromosomal anomalies for a false-positive rate of about 5%. Increased NT may indicate the presence of structural defects or genetic disorders, and it is relatively frequently seen in monochorionic pregnancies prone to develop twin-twin transfusion syndrome.

First-trimester increased nuchal translucency and fetal hypokinesia associated with Zellweger syndrome

We report the prenatal detection of increased nuchal translucency and decreased fetal movements, at 11 weeks of gestation, in a fetus at risk for Zellweger syndrome. The diagnosis of Zellweger syndrome was confirmed by metabolic studies on cultured chorionic villus sampling (CVS) cells and the pregnancy was terminated. The couple's subsequent pregnancy was monitored using the same method. In this pregnancy the nuchal translucency measured at 12 weeks' gestation was normal, the fetus was active, and biochemical studies using CVS and amniocentesis confirmed normal results. We believe this to be the first reported case of Zellweger syndrome followed prenatally in which an increased nuchal translucency and fetal hypokinesia were detected in the first trimester. During the pregnancy with the affected child the maternal serum screen (MSS) showed low estriol level. We believe this to be the second report of a low estriol level on MSS in a pregnancy affected with Zellweger syndrome.

Fanconi anemia associated with increased nuchal translucency detected by first-trimester ultrasound

Increased nuchal translucency between 10 and 14 weeks of gestation has now been established as a marker for chromosomal defects in several large-scale studies. In addition, a growing number of structural defects and some rare genetic syndromes have been identified in association with this marker. We describe a case of a fetus with increased nuchal translucency at 12 weeks of gestation, in which second-trimester evaluation by ultrasound showed an enlarged cisterna magna, a ventricular septal defect and moderate signs of dysmorphia. Karyotyping by chorionic villus sampling revealed a high rate of chromosomal breaks. The diagnosis of Fanconi anemia with early onset was confirmed following the development of severe postnatal anemia 2 months after birth.

Variability in the phenotypic expression of fryns syndrome: A report of two sibships

We report on two sibships with four fetuses of 12, 15, 17, and 20 weeks of gestation, respectively, and 1 preterm baby of 31 weeks of gestation affected by a multiple congenital disorder with manifestation suggestive of Fryns syndrome. In addition to the characteristic malformation pattern in Fryns syndrome, they presented with fetal hydrops, cystic hygroma, and multiple pterygias, allowing prenatal ultrasound diagnosis as early as in the 11th week of gestation. The two affected fetuses of family 1 showed severe craniofacial anomalies with bilateral cleft lip and palate, acral hypoplasia, postaxial oligodactyly, persistent truncus arteriosus, and interrupted aortic arch, asplenia sequence, and complex central nervous system midline malformations. In family 2 with three affected sibs, ear anomalies with atresia of the auditory canals, postaxial hexadactyly, intestinal atresias, callosal defects, and eye colobomas were the most outstanding features. On the basis of the present findings and former reports, the inter- and intrafamiliar phenotypic variability in Fryns syndrome, possible pathogenetic mechanisms, and the value of prenatal diagnosis are discussed. In the pathogenetic discussion, a special emphasis is put on the neural crest cell developmental field.

Increased nuchal translucency in a case of long-chain 3-hydroxyacyl- coenzyme A dehydrogenase deficiency

We present a case where the embryo showed an increased nuchal edema and a metabolic disorder. At 31 weeks of gestation the fetus developed a cardiomegaly and a hydrops. In this case, a long-chain 3-hydroxacyl-coenzyme A dehydrogenase deficiency (LCHAD deficiency) was confirmed by biochemical investigations in cultured chorionic villus cells and by DNA analysis. This metabolic disease causes a reduced production of mitochondrial trifunctional proteins and is a very rare autosomal-recessive disease.

First trimester screening for structural fetal abnormalities: nuchal translucency sonography

Nuchal translucency refers to the normal subcutaneous space, observed on first trimester ultrasound examination, between the skin and the cervical spine in the fetus. Increased nuchal translucency is known to be associated with an increased risk of aneuploidy, particularly Down syndrome. In addition to this association with aneuploidy, multiple studies have now identified increased nuchal translucency as a nonspecific marker of a wide range of fetal structural abnormalities, to include congenital diaphragmatic hernia, cardiac defects, and various genetic syndromes. The degree of nuchal translucency is directly related to the prevalence of fetal anomalies and may have prognostic significance, especially when found in association with other anomalies. The pathophysiology of increased nuchal translucency is uncertain but may be the result of cardiac failure or alterations in lymphatic drainage. Increased nuchal translucency may identify pregnancies that require further assessment, to include additional sonographic evaluation and possible fetal echocardiography. Further evaluation is required to assess the role of nuchal translucency screening in the general population.

Cystic hygroma in the fetus and newborn

Cystic hygromas are developmental abnormalities of the lymphoid system that occur at sites of lymphatic-venous connection, most commonly in the posterior neck. They are frequently associated with karyotypic abnormalities, various malformation syndromes, and several teratogenic agents. The disease course of an infant with cystic hygroma is unpredictable. When diagnosed prenatally, the overall prognosis is poor. Cystic hygroma diagnosed after birth is usually associated with a good prognosis. This article reviews the embryologic, genetic, and pathologic correlates of these lymphatic system abnormalities, as well as the clinical course and outcome of the fetus and newborn with a cystic hygroma. Management strategies are reviewed, including newer nonsurgical therapies for the neonate with a cystic hygroma.