The Use of Mouth Brushings for Screening Girls Who Present with Inguinal Hernia for Complete Androgen Insensitivity Syndrome

Introduction Published guidance recommends that all girls with inguinal hernia should be screened for complete androgen insensitivity syndrome (CAIS). We report a novel, noninvasive screening technique. Methods Retrospective review of all girls undergoing inguinal herniotomy from April 2009 to October 2010. Those screened using the novel technique of extraction of Y chromosome specific DNA from a buccal mucosal sample obtained by mouth brushing are reported. Results A total of 29 girls were screened by mouth brushing at median age 2.9 years (range 29 days to 9.3 years). Of the 29 samples, 25 were adequate for DNA extraction; 4 were inadequate and screening was repeated (3 repeat mouth brushing, 1 perioperative blood test). Mouth brushing was well tolerated by children and acceptable to parents. A preoperative blood test was avoided in all girls who had a mouth brushing. None of the girls in this study had CAIS. Turn-around time for mouth brushing was mean 4.9 days compared with a minimum of 10 days for a karyotype. This technique is cheaper than a karyotype (87 pound vs. 205) pound. Conclusion Extraction of Y chromosome specific DNA from a mouth brushing sample is effective for screening girls with inguinal hernia for CAIS. It is acceptable, cheaper, and quicker than alternatives.