Heritability of polycystic ovary syndrome in a Dutch twin-family study.
BACKGROUND
Polycystic ovary syndrome (PCOS) is one of the most common endocrine disorders among women of reproductive age. There is evidence for a genetic component in PCOS based on familial clustering of cases.


OBJECTIVE
In the present study, the heritability of PCOS was estimated.


METHODS
Data from 1332 monozygotic twins (genetically identical) and 1873 dizygotic twins/singleton sisters of twins (who share on average 50% of their segregating genes) registered with The Netherlands Twin Register were used. PCOS was defined as less than nine menstrual cycles and acne or hirsutism in agreement with the 2003 Rotterdam consensus.


RESULTS
Results point to a strong contribution of familial factors to PCOS. The resemblance in monozygotic twin sisters (tetrachoric correlation 0.71) for PCOS was about twice as large as in dizygotic twin and other sisters (tetrachoric correlation 0.38). Univariate analyses point to strong contributions of genetic factors to the variance in PCOS. Next, a trivariate genetic analysis of oligomenorrhea, acne, and hirsutism was carried out. This analysis confirmed that the familial component in PCOS is due to genetic factors.


CONCLUSIONS
This study demonstrated a large influence of genetic factors to the pathogenesis of PCOS, justifying the search for susceptibility genes.
Vink
J M
JM
Department of Biological Psychology, Vrije Universiteit, van de Boechorststraat 1, 1081 BT Amsterdam, The Netherlands. jm.vink@psy.vu.nl
Sadrzadeh
S
S
Lambalk
C B
CB
Boomsma
D I
DI
D000328:Adult; D004200:Diseases in Twins / Q000235:genetics*; D005260:Female; D006801:Humans; D011085:Polycystic Ovary Syndrome / Q000235:genetics*; D018433:Twin Studies as Topic; D014427:Twins; D014429:Twins, Dizygotic; D014430:Twins, Monozygotic