Prenatal Sonographic Features of CHARGE Syndrome

CHARGE syndrome with early fetal ear abnormalities: A case report

Key Clinical Message

CHARGE syndrome is a rare genetic disorder characterized by several distinct features. The presence of fetal ear abnormalities could be the early indicator of CHARGE syndrome. Subsequent prenatal diagnosis is essential to confirm the disorder. This is significant because the patient may receive genetic counseling and appropriate disposal based on the accurate diagnosis.

Abstract

CHARGE syndrome is a rare genetic disorder with multiple specific clinical features. The prenatal diagnosis is crucial but rarely achieved. We report a fetus with fetal external ear abnormality detected by ultrasound at 22nd week of gestation. Postnatal examination revealed an external ear abnormality, a mild atrial septal defect, and other clinical signs of CHARGE syndrome. A de novo pathogenic nonsense mutation in the CHD7 gene (c.406C > T, p.Q136X in exon 2) was identified to cause the disorder. Our study demonstrated that prenatal diagnosis and genetic testing were recommended to obtain a solid diagnosis of CHARGE syndrome when fetal external ear abnormality was detected by ultrasound examination.

Measurement of the Fetal Ear Length Has No Clinical Value

The long-term monitoring of a fetus with genetic and non-genetic anomalies is still a challenge for prenatal medicine. Ultrasound screening must be based on some measurement ranges, which show the trend of development of fetal body parts in a given period of time. One of them is the fetal ear auricle. This study presents an analysis of the fetal ear auricle length in healthy fetuses to establish normal ranges of fetal ear auricle length. The study group included 132 healthy fetuses. The gestational age of healthy fetuses ranged from 17.0 to 39.5 weeks of gestation according to LMP. The range of fetal ear length measurement was 10.00-40.00 mm with an average value of 23.49 mm. In the group of fetuses in the second trimester of pregnancy, the range of fetal ear length measurement was 18.00-28.00 mm, whereas in the group of fetuses in the third trimester of pregnancy, the range was 16.00-40.00 mm. In order to check the usefulness of this parameter, an analysis of this marker in fetuses with extracardiac anomalies, including genetic and non-genetic disorders is shown. The fetal ear measurement can fall within the normal range even if there are some genetic or non-genetic disorders. Therefore, the fetal ear measurement does not provide any diagnostic value in terms of detecting any fetal genetic and non-genetic disorders, which is supported by the analysis of the data provided in this study. Our study has proved that measurement of the fetal ear auricle is possible; however, its clinical usefulness for perinatal management is currently very limited.

Increased nuchal translucency with normal karyotype and genomic microarray analysis: A multicenter observational study

OBJECTIVE

To define the residual risk of morbidity-related outcome in fetuses with nuchal translucency (NT) of 3.5 mm or more after normal genetic testing and mid-trimester anomaly scan.

METHODS

A total of 114 fetuses with isolated NT of 3.5 mm or more, normal karyotype, and array-based comparative genomic hybridization (array-CGH) were included and divided in three groups: NT 3.5-4.5 mm, NT 4.5-6 mm, and NT greater than 6 mm. RASopathy testing and ultrasound follow up were performed in all fetuses. We evaluated: (1) incidence of genetic disorders; (2) incidence of structural abnormalities; (3) pregnancy outcome; (4) long-term pediatric outcome before (point 1) and after (point 2) a normal RASopathy testing and mid-trimester anomaly scan.

RESULTS

After normal karyotype and array-CGH the residual risk of morbidity-related outcome was 24.64% for NT 3.5-4.5 mm, 25% for NT 4.5-6 mm and 76.47% for NT more than 6 mm. After a normal RASopathy testing and mid-trimester anomaly scan the residual risks decreased to 7.14%, 8.69%, and 33.3% in the three groups, respectively.

CONCLUSION

In fetuses with an NT of 3.5 mm or more and both normal karyotype and array-CGH, the rate of morbidity-related outcome depends on NT size. A normal RASopathy testing and mid-trimester ultrasound are reassuring but the residual risk of morbidity-related outcome is increased compared with the general population, particularly if NT is greater than 6 mm.