Y-chromosomal microdeletions are the second most frequent genetic cause of male infertility and they occur in about one in 4000 men in general population but its frequency is significantly higher among infertile men. Azoospermic men have a higher incidence of microdeletions than oligosper- mic men (frequency 2-10%). Due to the results of an external quality control, the need of guide- lines for the detection of Y chromosomal microdeletions came to light. Therefore, the European Academy of Andrology (EAA) and the European Molecular Genetics Quality Network (EMQN) supported the publication of two “laboratory guidelines for molecular diagnosis of Y- chromosomal microdeletions” (Simoni et al, 1999-2004) and started offering external quality as- sessment (EQA) in accordance with the EAA/EMQN guidelines. The kit Ampli set Y Chromosome UE and FAM Y Chromosome UE allows the detection of Y chromosome microdeletions inside the three regions AZFa, AZFb, AZFc using 2 multiplex PCR mix. The STS (Sequenced Tagged Sites) investigated are assessed by the guide lines of EAA, as the internal controls ZFX/ZFY and SRY. The detection is performed on agarose gel or by frag- ment analysis (cat.1.501FAM). The kit Ampli set Y Chromosome Extension allows to confirm microdeletions, identified by the first step kit, and to analyze the entire deleted region, assessing if a deletion is partial or complete. The choice of markers is based on the EAA/EMQN.
Ampli set gr/gr Y chromosome: the AZFc region is particularly susceptible to homologous in- trachromosomal recombinations events, due to its repetitive structure, which may leads to dele- tions. New types of AZFc deletions called partial deletions or gr/gr deletions, have been reported. They remove about half of AZFc content, including two DAZ genes (CDY1 and BPY2). Italian gr/gr carriers have a 7.9 -fold increased risk of impaired spermatogenesis compared with men without such a deletion.
The Dia-chem srl gr/gr Y chromosome allows to detect the presence of gr/gr partial deletions us- ing specific primers for Sy1291 and SY1191 and for ß-globine as internal control of multiplex PCR.
Ampli set FSHβ -FSHR: The FSH or Follicle Stimulating Hormone is a glycoprotein hormone produced and secreted by adenohypophysis and contributes, in both sexes, to the regulation of the development, and pubertal maturation of reproductive process. Polymorphism -211 G> T (rs 10,835,638) influences the FSH levels in serum. This polymorphism, which causes the substitu- tion of a G with a T, is located in the promoter of the gene -211bp upstream of the transcript start site of mRNA. A statistically significant association between serum levels of FSH and FSH geno- types was found: heterozygotes (GT) or homozygous (TT) have serum FSH significantly lower than subjects WT (GG). Many studies, including Tüttelmann in 2012, found a significant correla- tion between the subjects carriers of T with serum levels of FSH (lower 24% in TT than GG), the relationship with FSH / LH, with the testicular volume and concentration and sperm counts (lower by 36% and 34% in TT than GG). FSH is able to carry out its stimulatory effects on gametogene- sis only if it binds to a specific receptor (FSHR). This receptor is located on the surface of the Ser- toli cells in the testis and on the surface of the ovary granulosa. The variant 2039 A> G (rs 6166) characterizes the haplotype of exon 10. In the protein, the replacement 2039 A> G causes the sub- stitution asparagine with serine. In women FSHR genotype related to these SNPs is the factor that most influences the ovarian responsiveness to FSH-treatment necessary for ovulation induction in the assisted fertilization techniques. The variant 2039 A> G reflects a reduced ovarian sensitivity in women requesting a dose of exogenous FSH higher in assisted fertilization techniques. It has been also shown a significant decrease of testicular volume by relating the various genotypes of SNP 2039 A> G genotypes and -211GT - 211TT of FSHβ.
The studies by Selice (2011) and Ferlin (2011) have shown that the analysis of genes and FSHR FSHβ is a valid pharmacogenetic approach in male since treatment with FSH is able to induce an improvement in semen parameters only in a subgroup of oligospermic patients with a specific genotype related to these two genes.