ovarian aging:

FMR1 Gene May Control Women’s Fertility Life Cycle, According to Research

0

New evidence about the FMR1 gene and ovarian agingOctober 23, 2012 (New York, NY) – A new study presented at the Annual Meeting of the American Society for Reproductive Medicine (ASRM) in San Diego, CA, offers further evidence that the fragile X mental retardation 1 gene (FMR1 gene) may play an important role in controlling  women’s fertility life cycles.

The study, conducted by researchers from the Center for Human Reproduction (CHR), a leading fertility center in New York City, and the Medical University of Vienna in Austria, compared the age of menarche (start of menstruation) and the number of CGG tri-nucleotide repeats on the FMR1 gene. Among the 222 women studied, a significant relationship was identified between the age of menarche and CGG counts. Specifically, women with at least one FMR1 allele with CGG counts higher than 34 were more likely to reach menarche after age 13 compared to women with CGG counts on both FMR1 alleles below 34.

The FMR1 gene has long been associated with neuro-psychiatric conditions, but only in recent years it has been shown to have controlling effects on women’s ovarian function. While for neuro-psychiatric risks, the FMR1 gene is considered normal up to CGG repeats of 55, the CHR investigators defined CGG counts between 26 and 34 as normal (norm) in regards to ovarian function, with CGG counts higher than 34 being defined as high and those lower than 26 as low. In a number of prior publications, the same group demonstrated genotypes and sub-genotypes of the FMR1 gene to be statistically associated with different ovarian aging patterns and IVF pregnancy rates.

“This study revealed that women with at least one high FMR1 allele tend to start their reproductive life later than women with low or norm alleles,” explains Norbert Gleicher, MD, Medical Director and Chief Scientists of CHR. “The finding further strengthens our hypothesis that the FMR1 gene has a significant influence on how a woman’s ovaries reach maturity, and then decline with age, defining her reproductive life cycle over her lifetime.”

Further studies are needed to better define how to predict a woman’s reproductive potential as she moves through life, based on FMR1 genotypes and sub-genotypes. Currently, prediction of female reproductive potential is difficult, and often impossible. Utilization of FMR1 genotypes and sub-genotypes may potentially open up new opportunities.

About Center for Human Reproduction
The Center for Human Reproduction (CHR, http://www.centerforhumanreprod.com/), located in New York City, is one of the world’s leading fertility centers. Because of its worldwide reputation as “fertility center of last resort,” CHR has a worldwide patient following among women with DOR, whether due to advanced age, or due to premature ovarian aging (POA). Dr. Gleicher is available for further comments.

Contact:
Communications Manager
Center for Human Reproduction
212-994-4400 x.4491


Continue Reading

New Genetic Test Predicts Better Egg Production for Women with Poor Ovarian Reserve, Study Shows

1

March 19, 2012 (New York, NY) – A genotype of the FMR1 (fragile X mental retardation) gene preserves a woman’s ability to produce CHReggs (oocytes) well into the 40s, according to an ovarian aging study just published in the medical journal PLoS One1.

Conducted at the Center for Human Reproduction (CHR), a fertility center in New York City specializing in fertility treatments for older women, the study compared egg yields during in vitro fertilization (IVF) in women above age 40 with varying FMR1 genotypes and sub-genotypes.

In women with very poor ovarian reserve (i.e., women with the poorest ovarian function), the FMR1 sub-genotype het-norm/high (normal CGG repeat count on one allele, abnormally high count on the other) produced significantly more eggs than other genotypes and sub-genotypes. This observation suggests that the het-norm/high FMR1 sub-genotype preserves a woman’s ability to produce a good number of eggs at older ages even if the ovarian reserve is severely reduced.

“From our previous research, we knew that the het-norm/high sub-genotype was responsible for slow recruitment of eggs into maturation process at younger ages than other genotypes and sub-genotypes,” explains Norbert Gleicher, MD, lead author of the study and Medical Director of CHR. “Because these women ‘use up’ fewer eggs from their egg reserve, we suspected that they may have more eggs left when older. This study confirmed this hypothesis, demonstrating that women with this sub-genotype performed better in IVF cycles than even women with normal FMR1 genotype.”

These findings further enhance the understanding of genetic control over the process of ovarian aging, and further refine prognostication in older women undergoing fertility treatments. Given that oocyte yields in IVF cycles usually correlate with pregnancy chances, older women with extremely low ovarian reserve, therefore, appear to have better chances of success if their FMR1 sub-genotype is het-norm/high.

 

1Gleicher N et al. The impact in older women of ovarian FMR1 genotypes and sub-genotypes on ovarian reserve. PLoS One 2012:e33638. [http://dx.plos.org/10.1371/journal.pone.0033638]

 

About Center for Human Reproduction

Center for Human Reproduction, or CHR (http://www.centerforhumanreprod.com), is a leading fertility center in the United States with a worldwide reputation as a “fertility center of last resort,” specializing in treatment of infertility in women with diminished ovarian reserve, including younger women with premature ovarian aging (POA) and older women with physiological ovarian aging. Dr. Gleicher is available for additional comments.


Continue Reading