Klinefelter syndrome is the most common sex-chromosome disorder in men with a prevalence of 1 in 660 men. The syndrome is associated with hypogonadism. Many patients with Klinefelter syndrome have psychological complaints and physical discomfort. Some patients report a positive effect of testosterone treatment, whereas others do not.

The aim of this study is:

(i) To investigate quality of life in patients with Klinefelter syndrome. (ii) To investigate functional, physical and mental health in patients with Klinefelter syndrome.

Questionnaire concerning mental and physical health and life quality are sent out to patients with KS and to age-, educational- and zipcode-matched men from the general population. The questionnaire include questions about housing, income, marital status, fatherhood, medication, chronic disease,school and education, attachment to the labor, sexual and erectile function, life quality, mental and physical health, satisfaction with life and symptoms of attention deficits hyperactivity disorders.

For the Klinefelter group:

Inclusion Criteria:

• Verified Klinefelter syndrome

Exclusion Criteria:

• none

For the control group:

Inclusion Criteria:

• age-,educational,and residence-matched

Exclusion Criteria:

• none

Klinefelter patients is recruited from endocrinology, genetics and fertility clinics in Denmark.

An age-, educational, and zipcode-matched control group was created from Statistics Denmark by extracting five randomly selected men for each KS subject