According to Nature Medicine, premature ovarian insufficiency (POI) is a prevalent cause of female infertility caused by early loss of ovarian function. POI is caused by several possible molecular causes, making it a complex condition. Researchers sequenced the exomes of 1,030 people with POI to look for gene mutations that potentially have a role in the disease. In 193 (18.7%) individuals, they found 195 pathogenic and probable pathogenic mutations in 59 genes related to POI.
Additional POI-associated genes with a high burden of loss-of-function mutations were found in association studies comparing the POI cohort to a control cohort of 5,000 patients without POI. Among the roles revealed for the 20 unique genes were gonadogenesis (LGR4 and PRDM1), meiosis (CPEB1, KASH5, MCMDC2, MEIOSIN, NUP43, RFWD3, SHOC1, SLX4, and STRA8), folliculogenesis (SLX4), and ovulation (STRA8) (ALOX12, BMP6, H1-8, HMMR, HSD17B1, MST1R, PPM1B, ZAR1, and ZP3).
Pathogenic or putatively pathogenic mutations in known POI-causing genes and new POI-associated genes accounted for 242 (or 23.5%) cases. Additional genotype-phenotype association studies demonstrated a more significant genetic contribution in primary amenorrhea cases compared to secondary amenorrhea cases. POI, or the loss of ovarian function before age 40, affects an estimated 3.7% of women, making it one of the most prevalent causes of female infertility.
POI can be caused by everything from genetic abnormalities to autoimmune illnesses to infections to iatrogenic interventions, highlighting the syndrome’s complexity. Many cases of POI, however, are idiopathic, and there is growing evidence that they have a genetic foundation for pathogenesis. As a result, understanding the molecular basis of POI is critical for directing genetic counseling and pregnancy planning and studying therapeutic alternatives such as in vitro activation.
Researchers collected data from a large cohort of 375 patients from 70 families in search of novel essential genes and altered signaling pathways to better understand this illness. Alternatively, the entire genome’s coding area has been sequenced, and 88 causative genes have been found. This study’s high success rate (29.3%) strongly supports routinely using genetics to identify all people with unexplained POI. Researchers revealed that patient-specific therapy is possible through molecular dissection of the underlying mechanisms.
Many of these malignancies (37.2%) include mutations in genes that help in DNA repair, meiosis, or mitosis, but there is also a gene family associated with an increased risk of cancer. Continuous monitoring throughout a patient’s life is required to discover these tumors early when they are most treatable.
The genes involved in follicular development are the second most important (35.4%). In 8.5% of cases, POI is the only visible symptom of a complex multi-organ hereditary disorder. The significant individual variation in the onset of PMS and natural menopause has been connected to three genes, with the intensity of the correlation perhaps correlated with the age of onset (which are significant in POI).
High-throughput sequencing developments have substantially aided their understanding of the pathophysiology of POI, with about 90 genes associated with either isolated or syndromic variants of the disorder. However, only a small number of patients have mutations in these genes, emphasizing POI’s remarkable genetic diversity.
Furthermore, earlier investigations lacked the controls and sample sizes required to demonstrate single-gene correlations and identify additional causal genes unambiguously. This study aimed to undertake the largest-ever whole-exome sequencing (WES) investigation in POI patients and evaluate the data in conjunction with a case-control cohort to understand this condition’s genetic underpinnings better.
Given the significance of genetic variations in POI in the population, existing POI care guidelines that prohibit thorough mutation screening in identified patients due to the alleged rarity of monogenic causes should be reassessed. This considerable cohort investigation found that at least 18-23% of POI patients had genetic abnormalities, supporting the use of regular clinical WES in POI. A good result from such a test might aid doctors in making more accurate diagnoses and pave the path for genetic counseling with the proband’s female relatives.
POI can develop gradually, moving through the occult (average FSH level with decreased fertility), biochemical (elevated FSH level with regular menses), and overt (irregular menses) stages. If a woman’s ovarian reserve decreases owing to genetic mutations, she should seek reproductive advice promptly, such as family planning, fertility preservation, or assisted reproduction technology.
This research provides a thorough examination of pathogenic variations in POI, increasing the breadth of known POI-associated genes and thereby aiding in the creation of a picture of the genetic landscape of POI. To address the limitations of this work and get a more profound knowledge of the genetic roots of POI, larger cohort sizes, sequencing of parent-proband trios, advanced genomic technologies, and global collaborative research are all required.
Mapping the genetic landscape of individuals with ovarian function disorders such as inadequate ovarian reserve, early menopause, and premature ovarian insufficiency may give information on common genetic causes of reproductive aging.
