Tracking microdeletions of the AZF region in a patrilineal line of infertile men

Abstract

ABSTRACT. Male infertility is considered to be a difficult-to-treat condition because it is not a single entity, but rather reflects a variety of different pathologic conditions, thus making it difficult to use a single treatment strategy. Structural alterations in the Y chromosome have been the principal factor responsible for male infertility. We examined 26 family members of 13 patients with male infertility who showed deletions in the AZF region. In family 1, the father and a brother did not show microdeletions. However, a son showed a microdeletion in AZFa (sY84) and an azoospermic sperm analysis, but another son had a microdeletion in AZFa (sY84) and AZFb (sY127) and a normal sperm analysis. The father of family 2, with severe oligozoospermia, had a microdeletion in the AZFa region (sY84) and his son, conceived by intracytoplasmic sperm injection, also showed the same microdeletion. In the other families, only the men with an altered sperm analysis had a microdeletion. It is possible that in family 1, the father and brother who did not show microdeletions in this study, could have microdeletions in regions upstream or downstream of the one analyzed. The treatment with intracytoplasmic sperm injection can result in vertical transmission of microdeletions of the AZF region and can also cause the expansion of a de novo mutation. This finding reinforces the necessity of an

Screening for partial AZFa microdeletions in the Y chromosome of infertile men: is it of clinical relevance?

“…Exclusive deletion of the marker sY84 has been reported by several groups (27)(28)(29). It was recently demonstrated by sequencing to be a false positive partial deletion caused by a single nucleotide polymorphism located in the reverse primer sequence (30).…”

Correlation between Y chromosome microdeletion and male infertility

“…Microdeletions can result in varying degrees of dyszoospermia, which ranges from azoospermia to severe oligospermia (Zhu et al, 2007;Martin, 2008). Studies have found that approximately 60% of Y chromosome microdeletions occur in the AZFc region (Rodovalho et al, 2008;Dai et al, 2015). AZFc deletion can generate diverse clinical phenotypes.…”

Pedigrees of infertile Chinese men with Y chromosome microdeletions derived from natural transmission and de novo mutation

“…Therefore, previous studies suggested that deletions are not transmitted to sons unless either in vitro fertilization or intracytoplasmic sperm injection is performed. Intracytoplasmic sperm injection may lead to vertical transmission, expansion, and de novo occurrence of Y chromosome microdeletions in male fetuses (Rodovalho et al, 2008;Mau Kai et al, 2008). However, data regarding the prevalence of father-to-son natural transmission are limited and it is unknown whether the deletion patient can be fertile based on clinical parameters such as testicular volume and reproductive hormone levels.…”