Full monosomy 21, prenatally diagnosed by fluorescent in situ hybridization.
We describe a case of full monosomy 21 which was prenatally diagnosed in chorionic villi by fluorescent in situ hybridization (FISH). Because of intrauterine fetal death, a curettage was performed and cytogenetic analysis of skin fibroblasts confirmed the presence of monosomy 21 in fetal cells. DNA investigations showed a paternal origin of the single chromosome 21. Inspection and autopsy of the fetus revealed several congenital malformations. Some of them have been reported in earlier studies of monosomy 21; others concern new observations. Regarding the eye, the following abnormalities were microscopically observed: absence of the anterior and posterior eye chambers, aniridy, a hypoplastic ciliary body, Peter's anomaly, and a double retina with secondary dysplasia. In addition, malformations of the extremities were seen: partial, proximal syndactyly of digits 3 and 4 of the right hand; pes varus position of the right foot; and transverse reduction defect at the tarsals of the left foot. To our knowledge, this is the first case in which full monosomy 21 has been proven.
Joosten
A M
AM
Department of Anatomy, Erasmus University/University Hospital Rotterdam, The Netherlands.
De Vos
S
S
Van Opstal
D
D
Brandenburg
H
H
Gaillard
J L
JL
Vermeij-Keers
C
C
D000015:Abnormalities, Multiple / Q000235:genetics / Q000473:pathology; D000028:Abortion, Induced; D000328:Adult; D000483:Alleles; D001344:Autopsy; D001345:Autoradiography; D015193:Chorionic Villi Sampling; D002891:Chromosomes, Human, Pair 21 / Q000235:genetics*; D005124:Eye Abnormalities / Q000196:embryology / Q000235:genetics / Q000473:pathology; D005260:Female; D005313:Fetal Death / Q000235:genetics* / Q000473:pathology; D005532:Foot Deformities, Congenital / Q000196:embryology / Q000235:genetics / Q000473:pathology; D006801:Humans; D017404:In Situ Hybridization, Fluorescence; D009006:Monosomy / Q000235:genetics* / Q000473:pathology*; D011247:Pregnancy