Endocrine Abstracts

Introduction: Disorders of sex development where females have a 46,XY karyotype can be seen. Main reasons for this are the conditions of androgen insensitivity syndrome (AIS) and gonadal dysgenesis. The clinical phenotype of both conditions is variable and can present from an undervirilized or infertile male to an individual with ambiguous genitalia at birth, to a pure female phenotype with unambiguous genitalia, who first present in adolescence with primary amenorrhoea and/or delayed puberty. The aim of the study was to estimate prevalence, incidence and diagnostic delay in 46,XY females in an unselected population in a nationwide study.

Design: A retrospective cohort study.

Patients and methods: From the Danish Cytogenetic Registry data of all cases registered as females and diagnosed with 46,XY or a related male karyotype in Denmark during 1965–2010 were retrieved. Cases were divided into subgroups of females having a 46,XY karyotype, mosaicism (45,X/46,XY; 46,XX/46,XY) and ‘other karyotypes’. Information of the background population was retrieved from Statistics Denmark.

Results: Age at diagnosis was mainly distributed in two periods with 29% diagnosed within the first year of life and 38% diagnosed during adolescence (13–20 years). Median age at diagnosis was 11.6 years (range: 0–46 years) and age at diagnosis increased significantly during the study period (P=0.005). There was no difference in age at diagnosis comparing the subgroups (Kruskal–Wallis Rank Sum=0.62). A prevalence of approximately six cases per 100 000 was observed during 1906–2010. During 1971–1990, the highest prevalence was observed with 13 cases per 100 000. From 1996 and forward the prevalence decreased.

Conclusions: Females with 46,XY and related male karyotypes are diagnosed with considerable diagnostic delay. Time trend in age at diagnosis shows increasing age at diagnosis during the study period. The prevalence of 46,XY female is higher than previously reported.