Prenatal diagnosis of de novo terminal deletion of chromosome 7q.
OBJECTIVE
To present the prenatal diagnosis and perinatal findings of a de novo terminal deletion of chromosome 7q.


METHODS
Amniocentesis was performed at 21-weeks gestation owing to a positive result of maternal serum multiple-marker screening. The 30-year-old woman, gravida 2, para 1, had a maternal serum multiple-marker screening test at 18-weeks gestation. The risk of Down syndrome was 1/11 calculated from the gestational age, maternal age, a maternal serum alpha-fetoprotein level of 1.026 multiples of the median (MOM), and a maternal serum free beta-human chorionic gonadotrophin (hCG) level of 8.678 MoM. Cytogenetic analysis of the cultured amniotic fluid cells revealed a de novo terminal deletion of 7q, 46,XX,del(7)(q35). Ultrasonography showed intrauterine growth restriction, microcephaly, and tetralogy of Fallot. The pregnancy was terminated subsequently. Grossly, the placenta was normal. On autopsy, the proband additionally manifested a prominent forehead, hypertelorism, epicanthus, upslanting palpebral fissures, a flat and broad nasal bridge, micrognathia, large low-set ears, overriding toes, and a normal brain. Radiography demonstrated a normal spine. Fluorescence in situ hybridization analysis demonstrated a 7q terminal deletion. Genetic marker analysis showed a maternally derived terminal deletion of chromosome 7(q35-qter).


CONCLUSIONS
Fetuses with a de novo 7q terminal deletion may be associated with a markedly elevated maternal serum hCG level and abnormal sonographic findings of intrauterine growth restriction, microcephaly, and congenital heart defects in the second trimester.
Department of Obstetrics and Gynecology, Mackay Memorial Hospital, Taipei, Taiwan, Republic of China. cpc_mmh@yahoo.com
Chih-Ping
CP
Chen
Schu-Rern
SR
Chern
Tung-Yao
TY
Chang
Chin-Yuan
CY
Tzen
Chen-Chi
CC
Lee
Wen-Lin
WL
Chen
Meng-Shan
MS
Lee
Wayseen
W
Wang
D000015:Abnormalities, Multiple / Q000000981:diagnostic imaging; D000025:Abortion, Eugenic; D000328:Adult; D000649:Amniocentesis; D006063:Chorionic Gonadotropin / Q000097:blood; D002872:Chromosome Deletion; D002897:Chromosomes, Human, Pair 7; D020732:Cytogenetic Analysis; D004247:DNA / Q000032:analysis; D005260:Female; D005317:Fetal Growth Retardation / Q000000981:diagnostic imaging; D005865:Gestational Age; D006801:Humans; D007231:Infant, Newborn; D008831:Microcephaly / Q000000981:diagnostic imaging; D016133:Polymerase Chain Reaction; D011247:Pregnancy / Q000097:blood; D013771:Tetralogy of Fallot / Q000000981:diagnostic imaging; D016216:Ultrasonography, Prenatal
D006063:Chorionic Gonadotropin; D004247:DNA