Children with 45,X/46,XY karyotype from birth to adult height

Growth pattern of children with 45,X/46,XY karyotype (X/XY children) has not been characterized.

Our objective is to describe growth pattern and long-term outcome of X/XY children and to develop guidelines for management of their short stature. Our hypothesis was that abnormal karyotype and deficiency of gonadal function might play a role in growth deceleration in X/XY children.

Retrospective record review and cohort follow-up of X/XY children were conducted between January 2005 and August of 2009. Sixteen X/XY children were evaluated and managed at a single institution as part of standard clinical care as established at the time between 1969 and 2009. The main outcome measures were clinical presentation, clinical characteristics, growth pattern, radiologic studies, pathological studies, and endocrine function of X/XY children.

Only X/XY female children underwent bilateral gonadectomy. As a group, X/XY female children were shorter at all age groups and at adult height relative to X/XY male children. Both groups manifested growth deceleration rather than growth spurt at the time of puberty. In both groups, adult height was compromised relative to mid-parental height.

X/XY children, similar to girls with Turner syndrome, benefit from growth hormone treatment. Deficiencies of both hypothalamic gonadal axis and primary gonadal function appear to play a role in their growth deceleration. Sex steroid replacement at the time of puberty has an important role in management.