Reproductive System & Sexual Disorders: Current Research
Open Access

Abstract

Correlation between Chromosomal Variants and Male Infertility in a Population of Brazilian Infertile Men

Denise Maria Christofolini, Fernanda Abani Mafra, Rubens Pedrenho Neto, Raphael Augusto Saab de Almeida Barros, Aline Amaro dos Santos, Carla Peluso, Marcello Machado Gava, Milton Ghirelli-Filho, Bianca Bianco and Caio Parente Barbosa

Heterochromatin polymorphism is considered a variant of a normal karyotype but is more frequent in infertile men. The aim of this study was to evaluate the correlation between heterochromatic variants and male infertility and to discuss the possible mechanisms of how heterochromatic polymorphism might affect spermatogenesis. Methods: Cytogenetic analysis was undertaken in a group of 392 infertile men from the Andrology Outpatient Clinic of the Human Reproduction Service of the ABC School of Medicine. Additionally, C-banding was performed in men with heterochromatin polymorphism, and NOR-banding in men with satellites variations. Results: 47 patients of the sample showed chromosomal variants (12% of the sample). Considering these men, 8 presented idiopathic infertility, where 19 presented severe oligozoospermia, 18 had non-obstructive azoospermia, 2 presented recurring pregnancy loss. The most frequent chromosome involved was chromosome 9, observed in 37.5% of the cases. Increased heterochromatin of chromosome 9 isolated was present in 8 men and pericentromeric inversion of chromosome 9 isolated was present in 7 men. Both aberrations were found in one man. Increased heterochromatin of chromosome 16 was found isolated in 6 cases and associated to other variation in 3 cases. For chromosome Y, variation in heterochromatin was found in 6 cases and associated to other variation in two cases and for chromosome 1, increased heterochromatin was found only associated to other variations. Satellites’ variation of chromosome 14 was found isolated in one case and associated in other case, of chromosome 21 was found isolated in 3 cases and associated in one case and of chromosome 22 was found isolated in 2 cases and associated in one case. Twenty men presented beyond chromosomal variations factors that couldn’t be discharged as cause of infertility as orchites and criptorchidia. Conclusions: The incidence of heterochromatin polymorphism was high in infertile men, as observed in the present work. This increased rate in infertile males seems to be more than an incidental finding, and must be considered an important factor contributing to male infertility.