philip deitiker

http://www.journals.uchicago.edu/AJH....abstract.html


Linkage Analysis of Extremely Discordant and Concordant
Sibling Pairs Identifies Quantitative Trait Loci Influencing
Variation in Human Menopausal Age

Kristel M. van Asselt,1,2,3,* Helen S. Kok,1,2,3,* Hein
Putter,4 Cisca Wijmenga,2 Petra H. M. Peeters,1 Yvonne T.
van der Schouw,1 Diederick E. Grobbee,1 Egbert R. te Velde,3
Sietse Mosselman,5 and Peter L. Pearson2

1Julius Center for Health Sciences and Primary Care,
2Department of Biomedical Genetics, and 3Department of
Reproductive Medicine, University Medical Center Utrecht,
and 4Department of Medical Statistics, Leiden University
Medical Center, Utrecht; and 5N. V. Organon, Oss, The
Netherlands

Received October 27, 2003; accepted for publication December
12, 2003; electronically published February 4, 2004.

Age at natural menopause may be used as parameter for
evaluating the rate of ovarian aging. Environmental factors
determine only a small part of the large variation in
menopausal age. Studies have shown that genetic factors are
likely to be involved in variation in menopausal age. To
identify quantitative-trait loci for this trait, we
performed a genomewide linkage study with age at natural
menopause as a continuous quantitative phenotype in Dutch
sister pairs, through use of a selective sampling scheme. A
total of 165 families were ascertained using extreme
selected sampling and were genotyped for 417 markers. Data
were analyzed by Haseman-Elston regression and by an
adjusted variance-components analysis. Subgroup analyses for
early and late menopausal age were conducted by
Haseman-Elston regression. In the adjusted
variance-components analysis, 12 chromosomes had a LOD score
of 1.0. Two chromosomal regions showed suggestive linkage:
9q21.3 (LOD score 2.6) and Xp21.3 (LOD score 3.1).
Haseman-Elston regression showed rather similar locations of
the peaks but yielded lower LOD scores. A permutation test
to obtain empirical P values resulted in a significant peak
on the X chromosome. To our knowledge, this is the first
study to attempt to identify loci responsible for
variability in menopausal age and in which several
chromosomal regions were identified with suggestive and
significant linkage. Although the finding of the region on
the X chromosome comes as no surprise, because of its
widespread involvement in premature ovarian failure, the
definition of which particular gene is involved is of great
interest. The region on chromosome 9 deserves further
consideration. Both findings require independent
confirmation.

can_hamilton

I find it ironic that this moron continues to make his pompous pronouncements on Usenet.
His never ending self absorbed postings of what can only on be laughably be called facts
is about as pathetic and inane as one Ed Conrad. Two bigger wastes of bandwidth do not
exist. The only reason for their existence is for everyone else to look down upon.
Deliciously sad and funny all rolled into a neat package.