Case Report

Live-Born with a Trisomy 22 Mosaic: A Case Report

by Barbara Baur Cavegn*, Julia Popelka, Suekrue Arioglu, Monya Todesco Bernasconi

Women’s Department, Kantonsspital Aarau, Switzerland Tellstrasse, Switzerland

*Corresponding author: Barbara Baur Cavegn, Women’s Department, Kantonsspital Aarau, Switzerland Tellstrasse, Switzerland

Received Date: 08 August 2023

Accepted Date: 12 August 2023

Published Date: 15 August 2023

Citation: Baur Cavegn B, Popelka J, Arioglu S, Todesco Bernasconi M (2023) Live-Born with a Trisomy 22 Mosaic: A Case Report. Ann Case Report 8: 1405.


Trisomy 22 mosaic is compatible with life with different degrees of neurological impairment. Diagnosis is often established in the second trimester due to malformations detected by ultrasound and subsequent amniocentesis. We report a case of a 36-year-old GIII, where the diagnosis was already established in the first trimester due to an abnormal combined first-trimester test and an abnormal result in a non-invasive prenatal test (NIPT) showing an increased signal for chromosome 22. Ultrasound examination revealed cardiac malformations and an abnormal fetal profile. Additionally, there was the suspicion of a situs inversus abdominis. We performed amniocentesis at 18 weeks of gestation which confirmed the diagnosis of trisomy 22 mosaic. The couple decided to continue the pregnancy. At 29 weeks the patient was admitted due to vaginal bleeding and uterine contractions. The ultrasound on admission showed intrauterine growth restriction. A cesarean section was performed at 30 weeks due to recurrent vaginal bleeding and worsening of fetal hemodynamics. A premature female with a birth weight of 670g (< 3rd percentile) and an APGAR score of 5/7/7 was delivered. Postnatally heterotaxy syndrome and azygos continuation with additional vascular anomalies and multiple ventricular septal defects (VSD) were confirmed. Postnatal FISH was considered compatible with a low-grade trisomy 22 mosaic. The girl is now nearly 4 years old and shows severe neurological and sensory-motor deficits. Counseling of parents with a fetus with trisomy 22 mosaic is extremely difficult since there is no correlation between the degree of mosaicism and neurological impairment.


Trisomy 22 is a common cause for spontaneous abortions in the first trimester [1]. The incidence of intrauterine death is very high and children born with a full trisomy 22 have a short life expectancy of only a couple of days [2,3]. Trisomy 22 mosaic on the other hand is compatible with life but is a rare condition [4]. Abdelgadir, [5] et al have previously summarized the most common clinical features. A lot of them can already be identified prenatally in the hands of a skilled sonographer. High maternal age seems to be a risk factor. Affected fetuses are more often female with a ratio of 1:1.6. Intrauterine growth restriction is present in up to 80% and postnatally failure to grow is seen in 70% of the affected children. In most cases, facial dysmorphia is detectable and about 75% show a congenital heart disease, most often ventricular septal defect (VSD), or atrial septal defect (ASD). Other clinical features include genitourinary tract abnormalities, hearing loss, hypotonia, and body asymmetry

Case Report

A 36-year-old GIII PI (1 healthy 6-year-old son and one early miscarriage) was first referred to our clinic at 16 2/7 weeks of gestation. The combined first-trimester screening had shown an increased risk of 1:139 for trisomy 21 despite a normal neck translucency and therefore a cell-free DNA test was performed. This test showed an increased signal for chromosome 22 and the patient was referred for counseling and invasive testing. During the first consultation, a detailed ultrasound examination was performed, which showed a female fetus with biometry in the normal range.

The profile showed a prominent forehead and mild retrognathia (figure 1).

Figure 1: Midsagittal scan of the fetal profile (B mode).

Neurosonography was unremarkable as far as assessable at early gestational age. The stomach could not be visualized in the left upper abdomen. In the right upper abdomen, a cystic structure was visible and therefore a situs inversus abdominalis could not be excluded. Fetal echocardiography revealed abnormal atrioventricular (AV) valves, and an atrioventricular septal defect (AVSD) or an atrioventricular canal defect was suspected. There was also reversed flow in the ductus venosus (DV).  The couple was informed in detail about the findings and genetic investigation by amniocentesis was recommended. After a reflection period, amniocentesis was performed without any complications at 17 3/7 weeks gestation. 5 out of 7 cell clones showed a free trisomy 22, revealing a trisomy 22 mosaicism.).

Another detailed ultrasound examination was performed at 20 weeks of gestation and showed a perimembranous VSD and a suspected ASD. The forehead was still prominent and there was no stomach in the left upper abdomen. In addition, we found a cystic structure in the cerebellar region (figure 2).