RT Journal Article SR Electronic T1 XO/XY mosaicism in phenotypic males. JF Archives of Disease in Childhood JO Arch Dis Child FD BMJ Publishing Group Ltd and Royal College of Paediatrics and Child Health SP 891 OP 892 DO 10.1136/adc.65.8.891 VO 65 IS 8 A1 K Walker A1 A J Gunn A1 P D Gluckman YR 1990 UL http://adc.bmj.com/content/65/8/891.abstract AB Eight cases of 45 XO/46 XY mosaicism are described: four were phenotypic males. Karyotyping should be performed more frequently in short boys as growth hormone treatment and testicular biopsy, to screen for carcinoma in situ, are likely to be beneficial.