Genetic studies in azoospermic patients with the Klinefelter pattern of testicular biopsy

82 male patients presenting functional azoospermia and klinefelter pattern of testicular biopsy were subjected to genetic, histopathologic, anthropometric and clinical studies. With finer methods of analysis, heterogeneity, within a disorder previously thought to represent one entity is usually revealed. Results of the present investigation suggest that sex chromatin counts cannot substitute chromosomal analysis for the discover of mosaiscism. The study also showed a marked phenotypic overlap between the X-chromatin positive Klinefelter disease and the X-chromatin negative Klinefelter syndrome. This overlap occurs both at the clinical level, documented by anthropometry and histopathologic findings in the testicular biopsy, emphasizing the importance of cytogenetic studies. Cases without the chromosomal aberration in whom we suspect environmental etiology may be described a sphenocopies of the genetic disorder.