SMYD1 is the underlying gene for the AnWj-negative blood group phenotype.

Background: AnWj is a high-incidence blood group antigen associated with three clinical disorders: lymphoid malignancies, immunologic disorders, and autoimmune hemolytic anemia. The aim of this study was to determine the genetic basis of an inherited AnWj-negative phenotype.

Methods: We identified a consanguineous family with two AnWj-negative siblings and 4 additional AnWj-negative individuals without known familial relationship to the index family.

X inactivation testing for identifying a non-syndromic X-linked mental retardation gene.

The purpose of this study was to identify a gene causing non-syndromic X-linked mental retardation in an extended family, taking advantage of the X chromosome inactivation status of the females in order to determine their carrier state. X inactivation in the females was determined with the androgen receptor methylation assay; thereafter, the X chromosome was screened with evenly spaced polymorphic markers. Once initial linkage was identified, the region of interest was saturated with additional markers and the males were added to the analysis.