Prenatal Diagnosis of Down Syndrome Associated with Right Aortic Arch and Dilated Septum Cavi Pellucidi

Abstract

A 30-year-old woman with a normal first trimester Down syndrome screening attended our ultrasound unit for a 20-week scan. The most remarkable anomalies were the presence of a right aortic arch along with a dilated cavum septi pellucidi. In addition, the scan showed an atrioventricular canal and bilateral choroid plexus cysts. Fetal karyotype showed the existence of trisomy 21. A novel association between Down syndrome and dilated cavum septi pellucidi is reported and the relationship between DS and vascular rings is discussed.

Levodopa-Responsive Early-Onset Parkinsonism in Down Syndrome

“…Hydrocephalus is rare in DS and cavum septum pellucidum cyst has been reported prenatally in a single case of DS [ 7 ]. Parkinsonian features can occur in hydrocephalus due to involvement of terminal dopaminergic neurons bordering the lateral ventricles [ 8 ] or due to mechanical distortion and consequent vascular insufficiency in the nigrostriatal system.…”

Outcome of a right aortic arch diagnosed in utero

“…Li et al 6 reported a single case of trisomy 21 in 41 cases, with no cases of DiGeorge syndrome, although it is unclear whether genetic testing for 22q11.2 microdeletion was performed. Furthermore, another fetus with RAA and trisomy 21 was described in a study by Morales-Rosello et al, 7 suggesting that it may not be an incidental association. Most recently, Perolo et al, 10 diagnosed DiGeorge syndrome prenatally in 8.5% of RAA, particularly higher when the thymus was small or undetected and in the presence of additional sonographic abnormalities.…”

“…This poses great difficulty in counseling parents of fetuses with this finding during prenatal screening.Previous studies examining the ability to diagnose an RAA in the fetus focused on identifying the aortic arch either in the general population 1,2 or in tertiary centers. [3][4][5][6][7][8][9] Unfortunately, the first group included low numbers and only short-term outcomes, and the second group included a large proportion of fetuses with multiple anomalies. 4-8 Furthermore, the statistical analysis for the latter group is limited as it does not include cases of RAA who have not been diagnosed by their primary obstetrician, and therefore not referred to tertiary centers.Early sonographic prenatal screening is almost routinely performed in Israel since 1987 at 14-16 weeks of gestation.…”