[48,XXYY men with azoospermia: how to manage infertility?]

Rare sex chromosome variation 48,XXYY: An integrative review

While the most common Sex Chromosome Aneuploidy (SCA) is 47,XXY, other variations, such as 48,XXYY, are less studied, perhaps due to its rarity. 48,XXYY occurs with an estimated prevalence of 1:18,000-40,000 male births. This SCA is associated with a variety of complex physical, psychological, and neuroanatomical findings. The purpose of this integrative review is to summarize the available evidence related to 48,XXYY and identify gaps in the literature. This study utilized integrative review and PRISMA-guided methodology to search six databases for information pertaining to 48,XXYY. There were no exclusion criteria related to design methodology, given the paucity of available research. Among 397 articles reviewed for potential inclusion, 30 articles remained after inclusion and exclusion criteria were applied. Seven of these articles concentrated solely on participants with 48,XXYY. Literature was summarized into categories of physical phenotype, psychosocial, behavioral, neurocognitive, and brain function. Clinical description of 48,XXYY has evolved over time to develop a deeper understanding of this complex disorder. Large gaps remain, especially a lack of experimental studies, clinical guidelines, and treatments. Additionally, few studies explore methodologies such as interviews or self-report surveys in this population. 48,XXYY presents with a wide spectrum of physical, psychological, and neurocognitive symptoms, and frequently requires complex interdisciplinary care. In order to better understand this disorder and to appropriately treat the individuals affected by it, future research should focus on experimental studies and research that utilizes a variety of methods, including participant interviews and patient-report surveys.

The Role of Number of Copies, Structure, Behavior and Copy Number Variations (CNV) of the Y Chromosome in Male Infertility

The World Health Organization (WHO) defines infertility as the inability of a sexually active, non-contracepting couple to achieve spontaneous pregnancy within one year. Statistics show that the two sexes are equally at risk. Several causes may be responsible for male infertility; however, in 30–40% of cases a diagnosis of idiopathic male infertility is made in men with normal urogenital anatomy, no history of familial fertility-related diseases and a normal panel of values as for endocrine, genetic and biochemical markers. Idiopathic male infertility may be the result of gene/environment interactions, genetic and epigenetic abnormalities. Numerical and structural anomalies of the Y chromosome represent a minor yet significant proportion and are the topic discussed in this review. We searched the PubMed database and major search engines for reports about Y-linked male infertility. We present cases of Y-linked male infertility in terms of (i) anomalies of the Y chromosome structure/number; (ii) Y chromosome misbehavior in a normal genetic background; (iii) Y chromosome copy number variations (CNVs). We discuss possible explanations of male infertility caused by mutations, lower or higher number of copies of otherwise wild type, Y-linked sequences. Despite Y chromosome structural anomalies are not a major cause of male infertility, in case of negative results and of normal DNA sequencing of the ascertained genes causing infertility and mapping on this chromosome, we recommend an analysis of the karyotype integrity in all cases of idiopathic fertility impairment, with an emphasis on the structure and number of this chromosome.