Phenotypic spectrum of 45,X/46,XY males with a ring Y chromosome and bilaterally descended testes

Objective: To characterize the phenotypic spectrum of males with bilaterally descended testes and a 45,X/46,X,(r)Y karyotype. Design: Retrospective review of patient records; cytogenetic and molecular analysis. Setting: Tertiary medical center setting. Participant(s): Five males, two prepubertal and three postpubertal, with a 45,X/46,X(r)Y karyotype and bilaterally descended testes. Intervention(s): Linear growth evaluation, testicular endocrine and exocrine studies, cytogenetic and molecular analysis on each patient. Main Outcome Measure(s): Clinical phenotype versus genotype. Result(s): Both prepubertal males had short stature and low testosterone. All three adults had normal puberty and normal testosterone levels. Two of the adults (one with short stature and one with normal stature) had elevated gonadotropins and azoospermia. The third adult had normal stature, severe oligospermia, normal gonadotropins, and normal serum testosterone. Conclusion(s): The phenotypic spectrum of males with a 45,X/46,X(r)Y karyotype and bilaterally descended testes varies greatly from males with short stature and spermatogenic failure to males without short stature and less severely affected spermatogenesis. This broad spectrum of phenotypic findings needs to be taken into account when the clinical geneticist encounters a prenatal diagnosis of a 45,X/46,X(r)Y karyotype. This information will also be helpful for pediatric and reproductive endocrinologists in counseling males with bilaterally descended testes and a 45,X/46,X(r)Y karyotype.