Chromosomal abnormality involving a complete or partial absence of the second sex chromosome, occurring in approximately 1 in 2500 live female births.
Characteristic clinical features include short stature and premature ovarian failure in a phenotypic female.
Variable phenotype; obvious stigmata such as neck webbing affect only 20% to 30% of patients.
Haploinsufficiency for X- or Y-encoded pseudoautosomal genes largely responsible for the phenotype.
Intelligence is normal, with verbal skills generally greater than performance or visual-spatial skills.
Disorders of Sex Development Program
Seattle Children’s Hospital
Associate Professor of Pediatrics
University of Washington
PYF is an author of a reference cited in this monograph.
Dr Patricia Y. Fechner would like to gratefully acknowledge Dr Carolyn A. Bondy, a previous contributor to this monograph. CAB is an author of a number of references cited in this monograph.
University College London Hospitals
GC declares that he has no competing interests.
Developmental Endocrinology Research Unit
Institute of Child Health
PH declares that he has no competing interests.
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