Prenatal diagnosis of mos45,X/46,X,+mar in a fetus with normal male external genitalia and a literature review.
OBJECTIVE
Prenatal diagnosis of mos45,X/46,X,+mar is difficult in genetic counseling. Patients with the presence of a Y-derived marker may manifest male or female external genitalia. Here, we report a fetus with phenotypically male external genitalia of mos45,X/46,X,+mar. In addition, the cases with prenatally detected mos45,X/ 46,X,del(Y)(q11.2) and normal male external genitalia are reviewed.


METHODS
A 30-year-old, primigravid woman was referred for amniocentesis because of an abnormal Down syndrome screening result at 20 weeks' gestation. Cytogenetic analysis showed mos45,X/46,X,+mar without a normal Y chromosome. Prenatal ultrasound detected symmetric intrauterine growth restriction and normal male external genitalia. After termination of the pregnancy, a phenotypically normal male fetus was delivered smoothly without apparent structural defects. Based on conventional G-banded analysis, the marker chromosome appeared as a Y chromosome that originated with a deleted Yq, designated as del(Y)(q11.2).


CONCLUSIONS
Based on a literature review, the addition of fluorescence in situ hybridization and molecular analysis to the conventional cytogenetic techniques can provide more accurate identification of a Y chromosome aberration in the prenatal detection of mos45,X/46,X,+mar, thus allowing more appropriate genetic counseling for the family.
Department of Obstetrics and Gynecology, China Medical University Hospital, Taichung, Taiwan.
Shu-Chin
SC
Chien
Chih-Ping
CP
Chen
Chyi-Chyang
CC
Lin
Li-Chia
LC
Huang
Cheng-Tiao
CT
Hsieh
Fuu-Jen
FJ
Tsai
D000328:Adult; D041321:Chromosomes, Human, X; D041322:Chromosomes, Human, Y; D005260:Female; D005819:Genetic Markers; D005837:Genitalia, Male; D006801:Humans; D017404:In Situ Hybridization, Fluorescence; D008297:Male; D011247:Pregnancy; D011296:Prenatal Diagnosis; D012729:Sex Chromosome Aberrations
D005819:Genetic Markers