Molecular and Biochemical Aspects of Hyperprolactinemia in infertile Women

   This study was constructed to investigate hyperprolactinemia related infertility through  a biochemical and molecular base   associated with single nucleotide polymorphism (SNP) at prolactin gene and prolactin receptor gene in hyperprolactinemic patients. The study included one hundred fifty blood samples from patients suffering hyperprolactinemia and infertility during the period from March
2014 to September 2014, collected from Kamal Al-Sammaraee and AlAlwyaa Hospital. Fifty blood samples from women were collected serving as the control group. The average ages of patients were 20 to 50 years. The  biochemical study utilized the 150 samples that were first divided into 2 groups according to two infertility groups (primary and secondary) so as  to study in which group the effect of hyperprolactinemia was manifested.Then,  the subjects were divided into three age groups, (20-30),(31-40) and (41-50), years old in order to identify the effect of higher prolactin hormone level on age group. Serum samples for all hyperprolactinemic patients were analyzed to detect the fertility hormones Luteinizing hormone (LH) , Follicle stimulating hormone (FSH) and prolactin hormone (PRL) which were
performed in all subjects. It was found that there is a significant difference in hormone concentration in serum patients when compared to the normal. Hormones (Luteinizing hormone )(LH) and (Follicle stimulating hormone) (FSH), recorded a significant decrease, while prolactin recorded a significant increase when compared to the normal. The decrease of the two fertility hormones FSH and LH  was  in the second fertile group while  PRL  increased more in this group. The greatest decrease of the two fertility hormones LH and FSH and the greatest increase of PRL hormone was in the age group (31-40) years
old. The variation in gene responsible for the synthesis of prolactin was conducted using samples of hyperprolactinemic patients. The study confirmed the incidance of  SNPs detected in prolactin gene of
hyperprolactinemic patients. Polymerase chain reaction (PCR) was done using a specific set of primers. Eight primers were selected to amplify the exons region of the gene (2 to 5) in addition to intron 1.  Another 4 primers were designed to amplify  exon 1 of prolactin receptor gene (PRLR).  After optimization of the amplification condition, the product of (489, 533, 719, 475, 307, 306 and 436 bp), was sent for DNA sequencing which was the tool for the detection of variation within  patients, genes which may reveal the association of this variation of prolactin  gene to hyperprolactinemia. It was found  that  the percentage of substitution mutation was 88.46%, while the deletion mutation percent was 11. 54% in which the highest mutation number was in exon 2, which was 9 mutations This number is significant.  All mutations in this exon were  substitutions ,while the less mutation number was in exon 3 and exon4 which was 2 for each exon, one substitution and one deletion mutation in exon 3 while the two mutations in exon 4 were  substitution  only. This result is also significant.   No mutation was detected in exon 5. But in intron 1 of  gene, seven  mutations were detected by using primer 1, in which two of them were  deletion mutations and 5 were  substitutions, while in the same intron of the gene using primer 2, 6 substitutions  mutations  were detected  . The results of mutation detected in the PRL gene exons and intron region showed a presence of mutations in the samples of hyperprolactinemia patients. Such mutationswere common between patient samples, i.e., substitution mutations in exon 2 and exon 4. Besides, exon 1 of prolactin receptor was sequenced and it wasfound that there were one SNP was detected in hyperprolactinemic patientsIt was found that SNPs in the exons and introns of the PRL  gene weredetected and these polymorphisms alter  the expression attributable toaltered transcription factor gene binding.