Appears then using the EmailPage extension. Originally reported here but ...
MW 1.23.10 with PHP 5.4.45 (cgi-fcgi) and MySQL 5.1.73-log
SELECT user_name,up_value FROM `rg_user` LEFT JOIN `rg_user_properties` ON ((user_id = up_user) AND up_property = 'gender') WHERE user_name = 'DFRV - Regionalgruppe Berlin'
I am quite sure that this started with MW 1.23.9 Adding this issue to I18n because of GenderCache, however I might be wrong here.