FSHR, LHCGR and ESR1 Polymorphisms: Reproductive Function and Limits of Interpretation

Variants in FSHR (A2039G), LHCGR (G1777C, CTGGTT/del), and ESR1 (G2014A) are studied in reproductive research. The original Diagen Plus laboratory announcement described PCR testing for these variants. These labels should be checked against the actual laboratory report: unambiguous identification requires a reference sequence, transcript version, and standardized description or rs identifier.

A common polymorphism is not equivalent to a pathogenic mutation causing a monogenic disorder. It cannot automatically be assigned an “autosomal dominant” or “autosomal recessive” clinical inheritance pattern or regarded as the cause of infertility. Allele frequencies depend on population, and finding a variant does not itself determine treatment.

FSHR: Follicle-Stimulating Hormone Receptor

The gene is located at 2p16.3. The FSH receptor participates in ovarian granulosa cell and testicular Sertoli cell function, mediating hormonal responses and supporting gametogenesis.

A2039G has been investigated in relation to ovarian FSH sensitivity, cycle length, and semen parameters. However, a single genotype cannot reliably predict poor ovarian response, infertility, or increased sperm DNA fragmentation. The previously stated fragmentation threshold of >20% is not a universal consequence of this variant and depends on the assay.

LHCGR: LH/hCG Receptor

The gene is located at 2p16.3 and encodes the receptor for luteinizing hormone and human chorionic gonadotropin. In men, these signals contribute to Leydig cell development and function and androgen production; in women, they contribute to ovulation and maintenance of corpus luteum function.

The common G1777C and CTGGTT/del variants have been studied in relation to reproductive outcomes. Their presence does not establish polycystic ovary syndrome, anovulation, preeclampsia, or inevitable pregnancy loss. Rare pathogenic LHCGR variants can cause specific inherited disorders, but should not be conflated with ordinary polymorphisms.

ESR1: Estrogen Receptor Alpha

The gene is located at 6q25.1–q25.2. Its product is a nuclear receptor and transcription factor regulating tissue responses to estrogens. It participates in reproduction, growth, metabolism, and skeletal and other system functions.

Research associations involving G2014A do not allow a single result to predict oocyte or embryo quality or male or female fertility. Finding the allele is not an independent indication for higher gonadotropin doses, ICSI, or preimplantation genetic testing.

Using the Results

Investigation and treatment are based on the clinical diagnosis, age, history, semen analysis, and standard assessment of both partners. Validated measures, particularly AMH and antral follicle count, are used to predict ovarian response. Results for research polymorphisms should be discussed with a fertility specialist or clinical geneticist in light of the evidence limitations. Such a variant does not replace clinical diagnosis or automatically require assisted reproductive procedures.