Isodicentric Y chromosome: cytogenetic, molecular and clinical studies and review of the literature.
Dicentrics are among the most common structural abnormalities of the human Y chromosome. Predicting the phenotypic consequences of different duplications and deletions of dicentric Y chromosomes is usually complicated by varying degrees of mosaicism (45,X cell lines), which may, in some cases, remain undetected. Molecular studies in patients with dicentric Y chromosomes have been few, and only two studies have attempted to determine the presence of SRY (the putative testis-determining factor gene). We report an 18-year-old female with short stature, amenorrhea, hirsutism, hypoplastic labia minora, and clitoromegaly who has a 45,X/46,X,idic(Y)(p11.32)/47,X,idic(Y)(p11.32),idic(Y) (p11.32) karyotype. Southern analysis using Y-specific probes (Y97, 2D6, 1F5, pY3.4) and polymerase chain reaction (PCR) analysis using primers for ZFY and SRY were positive for all loci tested, indicating that almost all of the Y chromosome was present. Our findings and an extensive review of the literature emphasize the importance of molecular analyses of abnormal Y chromosomes before any general conclusions can be reached concerning the relative effects of the Y-chromosome abnormality and mosaicism on sexual differentiation.
Tuck-Muller
C M
CM
Department of Medical Genetics, University of South Alabama, Mobile 36688, USA.
Chen
H
H
Martínez
J E
JE
Shen
C C
CC
Li
S
S
Kusyk
C
C
Batista
D A
DA
Bhatnagar
Y M
YM
Dowling
E
E
Wertelecki
W
W
D000293:Adolescent; D002869:Chromosome Aberrations / Q000235:genetics*; D025063:Chromosome Disorders; D004247:DNA / Q000032:analysis; D005260:Female; D006801:Humans; D017404:In Situ Hybridization, Fluorescence; D007621:Karyotyping; D009030:Mosaicism / Q000235:genetics; D016133:Polymerase Chain Reaction; D014998:Y Chromosome / Q000235:genetics*
D004247:DNA