Concurrence of klinefelter syndrome with hypospadias and chordee in identical twins: a rare presentation.

Klinefelter syndrome (KFS), is the most common disorder of the sex chromosomes, affecting 1/1000 male births, and presents with underdeveloped secondary sexual characteristics, infertility, and increased urinary excretion of gonadotropin. External genitourinary malformations in KFS are not common, except for small testes. We present identical twins with a 47XXY karyotype and discordant hypospadias and concomitant chordee. To our knowledge, this is the first report of such an association. The diverse possible etiologies explaining the relationship between the presenting congenital defects in identical twins are discussed. We believe that 1 known genetic malformation such as KFS warrants additional urologic assessment.