2005-10-31-16 46XX/47XY + 22 mosaicism © Cuillier www.thefetus.net/
46XX/47XY + 22 mosaicism
Fabrice Cuillier, MD*, Carasset G#, MD, Lemaire P$, Deshayes M$ ,Mme Lagarde#
*Hôpital Félix Guyon, #Saint Clotild clinic, $Moufia street, SAINT DENIS, Reunion Island, France
A 30-year-old woman (second pregnancy) was referred to our unit at 24 weeks because of a suspicion of osteochondrodysplasia. The family history was unremarkable and the parents were unrelated. There was no family history of birth defects and genetic diseases. The first sonography performed at 13 weeks was normal (nuchal translucency = 0.5 mm) and the triple test was normal too (1/1500).
The short long bones and IUGR was documented at 24 weeks. A 2D ultrasound performed at 24 weeks and 32 weeks did not revealed any others anomalies. Doppler ultrasonography was normal. A 3D examination of the fetal face at 22 weeks revealed no others anomalies. The long bones were short, but there was any sign of bowing or fracturing. At 32 weeks, a scan revealed that long bones were all below the 3th percentile for gestation. Amniotic fluid was normal. The umbilical artery and the middle cerebral artery pulsatility index were in the normal range. Doppler studies of both uterine artery were normal too and showed no evidence of notching.
After counselling, the patients opted for invasive testing. Chromosome analysis after amniocentesis at 32 weeks showed a female karyotype with an extranumerary marker in cells examined 46 XX /47 XY + 22 (Mosaism T22 = 14 %). The parents had normal karyotypes. They were counselled regarding the chromosomal abnormality and decided to continue the pregnancy. The fetal pronostic was difficult to establish.
At 34 weeks, a new sonography discovered a mild ear hypoplasia and small preauricular tag near only the right ear. Absence of fetal bones growth was noted. The cardiotocogram was reactive. Two days later, the fetus was dead. A female infant was delivered (fetus weight 1450 g).
Postnatal assessment of the fetus confirmed the prenatal diagnosis. He presented a normal face. The head seems normal and both ears were small and posteriorly angulated with pretragal tags only near the right ear. There were anti mongoloid slant of the palpebral fissures, epicanthal folds but any coloboma. The neck, chest, abdomen and genitalia were normal. There was no evidence of imperforate anus.
Figure1: 3D view showing normal fetus profile
Figure 2: Femur and tibia
Figure 3: Femur without signs of chondrodysplasia
Figure 4: Humerus without signs of chondrodysplasia
Figure 5: Humerus and radio
Figures 6,7 : 3D view of tibia, fibula and foot with normal appearance
Figure 8: 3D view showing right preauricular skin tags
Figure 9: Spiraled CT-scan showing no sign of chondrodysplasia
Figure 10: Postmortem view of fetal right profile. Note the preauricular tags.