Prenatal diagnosis of trisomy 6 mosaicism

We report on a fetus with multiple congenital anomalies detected at the prenatal ultrasound examination and a trisomy 6 mosaicism in the amniocytes. The pregnancy was interrupted in the 18th gestational week and the autopsy revealed malformations including cleft right hand, arthrogryposis and hypoplasia of the 4th digit of the left hand, syndactylies and overlapping toes, facial dysmorphism with hypertelorism and low-set ears, ventricular septum defect (VSD), intestinal malrotation and scoliosis. Trisomy 6 mosaicism was detected in cultured amniocytes (13.3%), confirmed in umbilical cord fibroblasts (40%) and by fluorescence in situ hybridization on other fetal tissues. Trisomy 6 mosaicism is a very rare finding with only eight cases previously reported to our best knowledge. Copyright © 2005 John Wiley & Sons, Ltd.     

Prenatal diagnosis of a de novo supernumerary marker derived from chromosome 16

Marker chromosomes are supernumerary chromosomes of unknown origin and are seldom found in prenatal diagnosis. Application of fluorescent in situ hybridization (FISH) allows the identification of the chromosomal origin of markers. Estimation of the risk of an abnormal phenotype outcome can be enabled by collecting data on phenotypes associated with markers of the same chromosomal origin. So far only very few cases of prenatal diagnosis of de novo supernumerary markers derived from chromosome 16 have been reported. Here the prenatal diagnosis of a de novo supernumerary marker chromosome 16 is described and the relevant literature discussed. Copyright © 2001 John Wiley & Sons, Ltd.     

Prenatal diagnosis of apparently isolated unilateral multicystic kidney: implications for counselling and management

Cases where initial prenatal diagnosis was made of isolated unilateral multicystic kidney (UMCK) were reviewed to determine appropriate counselling and management strategies. For the 73 cases, chromosome abnormalities, pregnancy complications and family histories were reviewed. In addition, subsequently diagnosed birth defects, and pediatric medical and surgical outcomes were available for 54 cases. Of those with outcome information available renal/genital–urinary tract abnormalities were diagnosed subsequently in 33% and non-renal abnormalities in 16% of cases. Of the non-renal abnormalities, congenital heart defects were most frequent (7%). One chromosome abnormality, a trisomy 21, was present among 32 cases where karyotypes were known (3%). Amniotic fluid volume abnormalities were present in 11 cases but not predictive of associated anomalies, with the exception of one case where polyhydramnios accompanied multiple malformations consistent with VATER association. A family history of structural renal anomalies was reported in 11 cases (20%). There were 14 cases of partial or complete involution (25%), including two cases of complete prenatal involution of the cystic kidneys. No long-term associated morbidity such as hypertension or malignancy was present in our cohort. Based on our study and corroborating literature, amniocentesis should be offered to women when a seemingly isolated UMCK is detected on routine prenatal ultrasound. Furthermore, a detailed ultrasound with careful assessment of the fetal heart and contralateral kidney is indicated at diagnosis and during the third trimester to assess for further evidence of structural abnormalities, as well as amniotic fluid volume abnormalities. Careful assessment of the newborn is indicated with appropriate speciality referral as required. Copyright © 2002 John Wiley & Sons, Ltd.