A case of an infertile male with a small supernumerary marker chromosome negative for M-FISH and containing only heterochromatin.
OBJECTIVE
To describe the case of a 32-year-old infertile male with small supernumerary marker chromosome (sSMCs) in 80% of peripheral lymphocytes.


METHODS
G-banding, C-banding, STRP analysis, M-FISH and molecule diagnosis of Y-chromosomal microdeletions were performed to determine the origin of sSMCs.


RESULTS
The karyotype of this patient was established as 47, XY, +mar/46, XY. C-banding showed that the marker chromosome was composed of heterochromatin without visible euchromatic material. No positive result was obtained in STRP, M-FISH and the microdeletion analysis of Y- chromosome.


CONCLUSIONS
The small supernumerary marker chromosome could play a causative role in male infertility although the mechanism remains to be elucidated.
Department of Medical Genetics, School of Medicine, Nanjing University, 22 Hankou Road, Nanjing 210093, China.
Wei
W
Wang
Yali
Y
Hu
Haiyan
H
Zhu
Jie
J
Li
Ruifang
R
Zhu
Ya-Ping
YP
Wang
D000328:Adult; D002871:Chromosome Banding; D002872:Chromosome Deletion; D041322:Chromosomes, Human, Y / Q000648:ultrastructure; D017931:DNA Primers / Q000235:genetics; D005819:Genetic Markers / Q000235:genetics*; D006570:Heterochromatin / Q000235:genetics*; D006801:Humans; D017404:In Situ Hybridization, Fluorescence / Q000379:methods*; D007248:Infertility, Male / Q000175:diagnosis* / Q000235:genetics*; D007621:Karyotyping; D008214:Lymphocytes / Q000378:metabolism; D008297:Male; D018895:Microsatellite Repeats / Q000235:genetics; D011110:Polymorphism, Genetic
D017931:DNA Primers; D005819:Genetic Markers; D006570:Heterochromatin