Maternal uniparental disomy for chromosome 22 in a child with generalized mosaicism for trisomy 22.
We report on a case of generalized mosaicism for trisomy 22. At chorionic villus sampling (CVS) in the 37th week of pregnancy, a 47,XX,+22 karyotype was detected in all cells. The indication for CVS was severe unexplained symmetrical intrauterine growth retardation (IUGR) and a ventricular septal defect (VSD) was noted. In cultured cells from amniotic fluid taken simultaneously, only two out of ten clones were trisomic. At term, a growth-retarded girl with mild dysmorphic features was born. Lymphocytes showed a normal 46,XX[50] karyotype; both chromosomes 22 were maternal in origin (maternal uniparental disomy). Investigation of the placenta post-delivery using fluorescence in situ hybridization showed a low presence of trisomy 22 cells in only one out of 14 biopsies. In cultured fibroblasts of skin tissue, a mosaic 47,XX,+22[7]/46,XX[25] was observed. Clinical follow-up is given up to 19 months.
de Pater
J M
JM
Clinical Genetics Centre, Utrecht, The Netherlands.
Schuring-Blom
G H
GH
van den Bogaard
R
R
van der Sijs-Bos
C J
CJ
Christiaens
G C
GC
Stoutenbeek
P
P
Leschot
N J
NJ
D000015:Abnormalities, Multiple / Q000235:genetics; D000328:Adult; D000483:Alleles; D001706:Biopsy; D015193:Chorionic Villi Sampling; D002892:Chromosomes, Human, Pair 22 / Q000235:genetics*; D005260:Female; D005317:Fetal Growth Retardation / Q000150:complications / Q000235:genetics* / Q000503:physiopathology; D005500:Follow-Up Studies; D006345:Heart Septal Defects, Ventricular / Q000150:complications / Q000196:embryology / Q000235:genetics; D006801:Humans; D007231:Infant, Newborn; D007621:Karyotyping; D018895:Microsatellite Repeats / Q000235:genetics*; D009030:Mosaicism / Q000235:genetics*; D010290:Parents; D010920:Placenta / Q000473:pathology; D011247:Pregnancy; D011256:Pregnancy Outcome; D011263:Pregnancy Trimester, Third; D011296:Prenatal Diagnosis / Q000379:methods; D014314:Trisomy / Q000175:diagnosis / Q000235:genetics*