No abstract

Male individuals with a 46,XX karyotype have been designated as XX males. In 80% of the cases, the presence of Yp sequences, including the male sex-determining gene, SRY, has been demonstrated by molecular and/or fluorescence in situ hybridization (FISH) analyses. In most cases, Yp sequences are located on the short arm of the X chromosome, resulting from unequal recombination between Yp and Xp during paternal meiosis. Much less frequent in XX males is the localization of the SRY gene to an autosome. Here we report on the genetic investigation of an atypical XX male in which the SRY gene was located at the end of the long arm of chromosome 1. The patient, with a normal male phenotype, was referred for azoospermia. Conventional cytogenetic analysis showed a 46,XX karyotype. Molecular-cytogenetics (FISH) and molecular (PCR and MLPA) studies identified not only Yp-specific sequences located on the distal long arm of chromosome 1 but also the deletion of the subtelomeric 1qter region. A specific phenotype has been reported for a deletion of the 1qter region associated with mental retardation. The molecular investigation of the 1qter region showed that in our patient the microdeletion is more telomeric than in patients reported with mental retardation. To our knowledge, this is the first report of a XX male with the Yp region transferred to the terminal long arm of chromosome 1. This is also the first microdeletion of the subtelomeric 1qter region not associated with mental retardation.

We have determined Y-chromosomal DNA haplotypes in 73 infertile European males carrying Y microdeletions and compared them with the haplotypes of 299 infertile males lacking microdeletions. Chromosomes were typed with a set of 11 binary Y markers, which identified 8 haplogroups in the sample. Haplogroup frequencies were compared between 3 microdeletion classes and the non-deleted infertile males. Deletions arise on many different haplotypic backgrounds. No statistically significant differences in frequency were seen, although the small number of AZFa deletions lay predominantly on one branch of the Y haplotype tree.

The aim of this study was to determine the prevalence of alterations and normal variable chromosome features in males from infertile couples. Karyotyping was performed to 84 men attending the infertility clinic at the Hospital Clinic i Provincial of Barcelona (Spain). Sex chromosome abnormalities were detected in 19 patients (26.62%): 14 (16.67%) aneuploidies 47,XXY and 47,XYY, 3 (3.57%) Y-chromosome long arm deletions; 1 (1.19%) mosaic 45,x/46,XY and 1 (1.19%) Robertsonian translocation (45.X-15-Y+t(15p: Yq). Chromosomal polymorphisms were observed in 29 patients. Yqh+ was the most frequent variant in sex chromosomes and increased length in heterochromatin and satellites were present in autosomal chromosomes. The high prevalence of chromosomal abnormalities observed in infertile men justify the use of karyotyping to evaluate males enrolled in new assisted reproductive technologies programs.