title: Mix gonadal dysgenesis associated with ring Y chromosome mosaics in a phenotypic male.
abstract: Ring chromosomes are present in 1 in 25,000 human fetuses; 99% arise de novo while less than 1% of rings are inherited. This chromosomal rearrangement may arise through a cytogenetic mechanism involving breaks in chromosome arms and fusion of the proximal broken ends, leading to a loss of distal material. Most patient Y ring chromosomes are present in a 45,X/46,X,r(Y) mosaic karyotype; molecular analyses of infertile men have shown that it is not rare to find r(Y) in these patients. However, the clinical spectrum in those cases with a 45,X cell line is broad and depends on the percentage of the monosomic cell line in different tissues. Y chromosome abnormalities and 45,X mosaic karyotypes are often associated with disorders of sex determination. Here, we report a male patient with hypospadias, cryptorchidism and a mosaic karyotype containing a low proportion of 45,X monosomic cells and multiple ring Y chromosomes in peripheral blood. Clinical, surgical, and molecular evidence was sufficient for a diagnosis of mixed gonadal dysgenesis. We suggest that a detailed cytogenetic and molecular analysis should be done in all males with bilateral descended testes and infertility.
authors.affiliation: Department of Human Genetics, Hospital General de México, Facultad de Medicina, Universidad Nacional Autónoma de México, Mexico City, Mexico.
authors.forename: J A
authors.initials: JA
authors.lastname: Lopez-Valdes
authors.forename: K
authors.initials: K
authors.lastname: Nieto
authors.forename: N
authors.initials: N
authors.lastname: Najera
authors.forename: A
authors.initials: A
authors.lastname: Cervantes
authors.forename: S
authors.initials: S
authors.lastname: Kofman-Alfaro
authors.forename: G
authors.initials: G
authors.lastname: Queipo
mesh_terms: D002467:Cell Nucleus / Q000378:metabolism; D002503:Centromere / Q000378:metabolism; D002648:Child; D002871:Chromosome Banding; D041322:Chromosomes, Human, Y / Q000235:genetics*; D006060:Gonadal Dysgenesis, Mixed / Q000235:genetics*; D006801:Humans; D017404:In Situ Hybridization, Fluorescence; D007399:Interphase; D007621:Karyotyping; D008297:Male; D008677:Metaphase; D009030:Mosaicism; D010641:Phenotype; D012303:Ring Chromosomes; D051876:Sex-Determining Region Y Protein / Q000378:metabolism
chemical_list: D051876:Sex-Determining Region Y Protein