Rare Case of 47XXY/46XX Mosaic Klinefelter Syndrome

The document discussed a rare case of 47XXY/46XX mosaic Klinefelter syndrome (KS) in a 39-year-old male, marking the 11th reported case with this specific mosaicism. The patient exhibited typical KS features such as small testes, gynecomastia, and hypergonadotropic hypogonadism, but also had male pattern baldness, which was common in his family. Chromosome analysis revealed 83% of cells were 47XXY and 17% were 46XX. The study highlighted that mosaic KS cases might be more androgenic and have a higher likelihood of spermatogenesis compared to non-mosaic KS. The presence of a Y chromosome in the gonad was crucial for determining the phenotype. The document emphasized the importance of considering KS mosaicism in cases of male infertility due to potential delays in diagnosis, as routine blood tests may not detect the 46XX cell line.