BACKGROUND: Endometriosis is known to cluster within nuclear families. The extent of familial clustering can be evaluated in Iceland with its large population-based genealogical database. METHODS AND RESULTS: Applying several measures of familiality we demonstrated that 750 women with endometriosis were significantly more interrelated than matched control groups. The risk ratio for sisters was 5.20 (P < 0.001) and for cousins 1.56 (P = 0.003). The average kinship coefficient for the patients was significantly higher than that calculated for 1000 sets of 750 matched controls (P < 0.001) and this remained significant when contribution from first-degree relatives was excluded (P < 0.05). The minimum number of ancestors required to account for the group of patients was compared with the minimum number of ancestors required to account for the control groups at different time points in the past. The minimum number of founders for the group of patients was significantly smaller than for the control groups. Affected cousin pairs were as likely to be paternally connected as maternally connected. CONCLUSIONS: This is the first population-based study using an extensive genealogy database to examine the genetic contribution to endometriosis. A genetic factor is present, with a raised risk in close and more distant relatives, and a definite kinship factor with maternal and paternal inheritance contributing.
BACKGROUND:Endometriosis is known to cluster within nuclear families. The extent of familial clustering can be evaluated in Iceland with its large population-based genealogical database. METHODS AND RESULTS: Applying several measures of familiality we demonstrated that 750 women with endometriosis were significantly more interrelated than matched control groups. The risk ratio for sisters was 5.20 (P < 0.001) and for cousins 1.56 (P = 0.003). The average kinship coefficient for the patients was significantly higher than that calculated for 1000 sets of 750 matched controls (P < 0.001) and this remained significant when contribution from first-degree relatives was excluded (P < 0.05). The minimum number of ancestors required to account for the group of patients was compared with the minimum number of ancestors required to account for the control groups at different time points in the past. The minimum number of founders for the group of patients was significantly smaller than for the control groups. Affected cousin pairs were as likely to be paternally connected as maternally connected. CONCLUSIONS: This is the first population-based study using an extensive genealogy database to examine the genetic contribution to endometriosis. A genetic factor is present, with a raised risk in close and more distant relatives, and a definite kinship factor with maternal and paternal inheritance contributing.
Authors: Jodie N Painter; Dale R Nyholt; Andrew Morris; Zhen Z Zhao; Anjali K Henders; Ann Lambert; Leanne Wallace; Nicholas G Martin; Stephen H Kennedy; Susan A Treloar; Krina T Zondervan; Grant W Montgomery Journal: Fertil Steril Date: 2011-04-16 Impact factor: 7.329
Authors: Grant W Montgomery; Dale R Nyholt; Zhen Zhen Zhao; Susan A Treloar; Jodie N Painter; Stacey A Missmer; Stephen H Kennedy; Krina T Zondervan Journal: Hum Reprod Update Date: 2008-06-05 Impact factor: 15.610
Authors: S Burghaus; P Klingsiek; P A Fasching; A Engel; L Häberle; P L Strissel; M Schmidt; K Jonas; J D Strehl; A Hartmann; J Lermann; A Boosz; F C Thiel; A Müller; M W Beckmann; S P Renner Journal: Geburtshilfe Frauenheilkd Date: 2011-12 Impact factor: 2.915
Authors: Peter A W Rogers; Thomas M D'Hooghe; Asgerally Fazleabas; Linda C Giudice; Grant W Montgomery; Felice Petraglia; Robert N Taylor Journal: Reprod Sci Date: 2013-02-20 Impact factor: 3.060
Authors: Zhen Zhen Zhao; Pamela M Pollock; Shane Thomas; Susan A Treloar; Dale R Nyholt; Grant W Montgomery Journal: Hum Reprod Date: 2008-02-18 Impact factor: 6.918