Frequency distribution of polymorphisms in the FSH receptor gene in infertility patients of different ethnicity.

Studies on the frequency distribution of follicle-stimulating hormone receptor (FSHR) polymorphisms report conflicting results. It has been suggested that ethnicity might influence these outcomes. Therefore, the aim of this study was to determine the frequency distribution of FSHR polymorphisms at position 680 of exon 10 within a large group of women with fertility problems from different ethnic backgrounds. A total of 1771 women of different ethnic origin (Caucasian, Asian, Hindustani, Creole and Mediterranean) were studied. FSHR single-nucleotide polymorphisms at codon 680 of exon 10 were determined by restriction fragment length polymorphism of amplicons generated by polymerase chain reaction. Genotypes were compared with serum FSH concentrations and between different ethnic groups. A significantly lower number of Asians (10.5%) were found to have the Ser680Ser receptor variant compared with Caucasians (21.5%) and Mediterraneans (22.3%) (P = 0.010). FSH concentrations did not differ between the various ethnic groups, or the different FSHR polymorphisms. In conclusion, the Ser680Ser receptor variant is less common in the Asian subgroup compared with Caucasians and Mediterraneans. This indicates that, when comparing allelic frequency distributions of the FSHR polymorphism variants, ethnic background should be accounted for. FSH concentrations did not differ between FSHR polymorphisms or between ethnic groups.

Frequency distribution of polymorphisms in the FSH receptor gene in infertility patients of different ethnicity.

Studies on the frequency distribution of follicle-stimulating hormone receptor (FSHR) polymorphisms report conflicting results. It has been suggested that ethnicity might influence these outcomes. Therefore, the aim of this study was to determine the frequency distribution of FSHR polymorphisms at position 680 of exon 10 within a large group of women with fertility problems from different ethnic backgrounds. A total of 1771 women of different ethnic origin (Caucasian, Asian, Hindustani, Creole and Mediterranean) were studied. FSHR single-nucleotide polymorphisms at codon 680 of exon 10 were determined by restriction fragment length polymorphism of amplicons generated by polymerase chain reaction. Genotypes were compared with serum FSH concentrations and between different ethnic groups. A significantly lower number of Asians (10.5%) were found to have the Ser680Ser receptor variant compared with Caucasians (21.5%) and Mediterraneans (22.3%) (P=0.010). FSH concentrations did not differ between the various ethnic groups, or the different FSHR polymorphisms. In conclusion, the Ser680Ser receptor variant is less common in the Asian subgroup compared with Caucasians and Mediterraneans. This indicates that, when comparing allelic frequency distributions of the FSHR polymorphism variants, ethnic background should be accounted for. FSH concentrations did not differ between FSHR polymorphisms or between ethnic groups.

A family history of twinning in relation to multiple implantation.

BACKGROUND: A familial basis for dizygotic twinning is known for multiple ovulation. However, for multiple implantation this remains unclear. In IVF/intracytoplasmic sperm injection (ICSI) 'multiple ovulation' is artificially induced. If multiple implantation is not hereditary, the incidences of twins in families of patients with single and multiple implantation after IVF/ICSI with double embryo transfer (DET) should be comparable. METHODS: A questionnaire study was conducted among patients with intra uterine pregnancy at 6 weeks of gestation, after IVF/ICSI treatment with DET 3 days after oocyte retrieval. RESULTS: There were 940 patients who gave their informed consent. For women with single implantation (Group A), the incidence of one and of multiple twins among the family was 27.2 and 15.5%, respectively. For women with multiple implantation (Group B), this incidence was 29.5 and 17.8%, respectively, P = 0.424. The incidence of one and of multiple twins among first degree relatives was 10.6 and 1.1% in Group A; for Group B this was 8.7 and 1.9%, P = 0.469. Multivariate regression analysis also did not reveal 'twins in family' or 'twins in first degree' as an associated variable for multiple implantation at 6 weeks. CONCLUSIONS: Incidences of twins in families of patients with single implantation and patients with multiple implantation after IVF/ICSI are comparable. Our data do not support the concept that multiple implantation is hereditary.