Sex of rearing seems to exert a powerful influence on gender identity in the absence of strong hormonal influence: report of two siblings with PAIS assigned different sex of rearing.

ABSTRACT

There is an ongoing debate regarding the relative contribution of nurture over nature in development of gender identity. Patients with partial androgen insensitivity syndrome (PAIS) have ambiguous genitalia and are known to be reared as male or female. Familial cases of PAIS sharing common hormonal defects are usually reared in the same sex. Here, we describe two siblings with PAIS, one reared as a male and the other as female. These two siblings presented at adolescence. Gender identity was concordant with the sex of rearing for both. The male sibling was distressed with gynecomastia that had disrupted his social life. The sex of rearing seems to have played a predominant role in the formation of gender identity in these two patients with PAIS.