Complete Androgen Insensitivity Syndrome in a child with 47,XYY

Program: Abstracts - Orals, Featured Poster Presentations, and Posters
Session: MON 631-640-Pediatric Endocrinology Case Reports: Disorders of Sexual Differentiation
Clinical
Monday, June 17, 2013: 1:45 PM-3:45 PM
Expo Halls ABC (Moscone Center)

Poster Board MON-634
Shanlee Marie Davis* and Sharon H Travers
University of Colorado, Aurora, CO
Introduction: Disorders of sex development (DSD) describe a heterogeneous group of disorders which are individually rare.  Sex chromosome aneuploidy (SCA) refers to a karyotype with an abnormal number of sex chromosomes. Here describe a new deletion mutation resulting in complete androgen insensitivity syndrome in a toddler with 47,XYY karyotype.

Clinical Case:  A 22-month-old female presented to Urology and Endocrinology clinics for a second opinion of removal of her left testis.  After an uncomplicated pregnancy and term birth she was noted to have a palpable right inguinal mass and later underwent laparoscopic removal of the mass that was reported to be testicular tissue.  Further inspection of her anatomy revealed a blind-ending vagina, no Mullerian structures, and an intraabdominal left testis.  Laboratory investigation at the time yielded a 47,XYY karyotype.  Parents chose to raise their child as female.  She has been growing and developing well, without difficulty in overcoming illnesses.  On exam, her height was 50%ile for age, weight 25%ile, and vital signs within normal limits.  She had significant labial adhesions but otherwise normal appearing external female genitalia.  Electrolytes, ACTH and renin, and intermediates in the steroid synthesis pathway were normal.  Sequencing of the androgen receptor gene revealed a deletion of 7 base pairs of the N-terminal domain.  This mutation has not yet been reported but proposed to lead to a premature stop codon and a nonfunctional protein.  These results and her phenotype are consistent with Complete Androgen Insensitivity Syndrome.

Parents elected to have the remaining testis removed.  Pathology revealed Sertoli cells with rare Leydig cells and fibrosis without malignant transformation; gonadal cells also had 47,XYY karyotype.  She will continue to follow with endocrinology for sex hormone replacement therapy at puberty.  The patient’s mother elected not to pursue genetic testing for herself to see if she is a carrier.

Discussion:  There are several case reports on XYY females, although this is the first report of identifying a mutation in the androgen receptor gene.  The two genetic mutations are likely isolated events that have co-occurred by chance in our patient, however a possible relationship cannot be excluded.  Correct diagnosis of DSD as well as SCA is important in counseling and management.

Naguib et al., Complete testicular feminization syndrome with 47, XYY Karyotype: A double hit phenomenon. Med Principles Pract 1997; 6:216-221

Nothing to Disclose: SMD, SHT

*Please take note of The Endocrine Society's News Embargo Policy at http://www.endo-society.org/endo2013/media.cfm