Home Page
References OMIM Gene GeneReviews HGMD HGNC
GENATLAS PHENOTYPE
last update : 23/01/2007
Symbol XXTD
Location Yp11
Name XX gonadal dysgenesis, SRY- positive
Other name(s) 46,XX testicular disorder of sex development, 46,XX testicular DSD XX male syndrome, SRY positive
Corresponding gene SRY
Other symbol(s) XXDSD
Main clinical features
  • 46,XX karyotype
  • male external genitalia normal in most cases, two testicles, no mullerian structure
  • at puberty small testis, gynecomastia, azoospermia
  • hypergonadotropic hypogonadism, testosterone deficiency if untreated
  • Genetic determination chromosomal
    Related entries SOX9, RSPO1
    Function/system disorder sex-genitalia
    Type malformation
    Mechanism(s)
    Gene mutationChromosome rearrangementEffectComments
      translocation   translocation of a normal SRY allele onto an X chromosome.
      translocation   translocation of a normal SRY allele onto an autosome in some cases
    Remark(s)
  • ~ 80 percent of XX males are SRY-positive and ~20 percent SRY-negative (MIM278850). Most cases occur de novo; if fertility is preserved sex-limited autosomal dominant inheritance may be observed with XX sibs having testicular DSD or true hermaphroditism
  • Genotype/Phenotype correlations True hermaphroditism (with both testicular and ovarian tissues) may also be observed; ambiguous genitalia are more often associated with SRY-negative TDSD (MIM278850).