46,X,del(X)(q13) Turner's Syndrome Female with Systemic Lupus Erythematosus in a Pedigree Multiplex for SLE

Systemic lupus erythematosus (SLE) disproportionately affects females. Recent work demonstrates that men with Klinefelter's syndrome (47,XXY males) have a similar risk of developing SLE as do genotypic females. We present an unusual case of an African American family with two SLE affected individuals in which one of the SLE patients also has Turner's syndrome [46,X,del(X)(q13)]. While not definitive, this family raises interesting questions regarding the role of genes located on the X chromosome in the development of SLE. The paucity of case reports documenting the overlap of SLE with Turner's syndrome while there is and association of male SLE with Klinefelter's syndrome suggests a lower risk of SLE in Turner's females. These observations are consistent with a gene dose effect at X with two X chromosomes (46,XX or 47,XXY) conferring higher risk and one X chromosome (46,XY or 45,XO) conferring lower risk of SLE.