Objective: To determine the prevalence and diagnosis rates of Klinefelter syndrome (KS) in Victoria, Australia, and compare these to previous international findings. Design, setting and participants: A Victorian population‐based descriptive study of all cytogenetic examinations resulting in a diagnosis of KS, including prenatal diagnoses from 1986 to 2006 and postnatal diagnoses from 1991 to 2006. Main outcome measures: Birth prevalence and diagnosis rates of KS. Results: The birth prevalence of KS in Victoria is estimated to be 223 per 100 000 males (95% CI, 195–254), with about 50% of cases remaining undiagnosed. Conclusions: KS may be occurring more frequently than has been reported previously, yet many cases remain undiagnosed. Our results highlight the need for increased awareness leading to timely detection.

Testicular germ-cell tumours of young adults are derived from a pre-invasive intratubular lesion, carcinoma in situ (CIS). In a recent genome-wide gene expression screening using cDNA microarrays, we found PDPN over-expressed in CIS compared to normal adult testis. PDPN encodes podoplanin (Aggrus, human gp36, T1A-2), a transmembrane glycoprotein expressed in lymphatic endothelium and various solid tumours. To examine a potential role for PDPN in testicular neoplasms and during testicular development, we investigated its expression pattern during the development of human testis and in a series of testicular CIS, gonadoblastoma and overt germ-cell tumours. We established by RT-PCR and by immunohistochemistry with a gp36 antibody that PDPN mRNA and the protein product were expressed in testes with germ-cell neoplasms but not in the normal adult testis. We also found gp36 expression in early foetal gonocytes and immature Sertoli cells, similar to the expression pattern of M2A antigen, a previously identified marker for CIS and seminoma. This reinforced our previous proposal that M2A (D2-40) antigen was identical to gp36 (podoplanin, Aggrus, T1A-2). Our findings also suggest that podoplanin has a function in developing testis, most likely at the level of cell-cell interactions among pre-meiotic germ cells and immature Sertoli cells.

This is the first quantitative study to show Klinefelter syndrome has a significant personal impact. Men diagnosed with Klinefelter syndrome later in life reported similar difficulties as those at younger ages, suggesting that they would benefit from early detection and intervention. Understanding factors influencing this can assist in providing adequate services to individuals with Klinefelter syndrome, their partners, families, and the health professionals caring for them.

Cysteine-rich secretory protein 2 (CRISP2) is a testis-enriched protein localized to the sperm acrosome and tail. CRISP2 has been proposed to play a critical role in spermatogenesis and male fertility, although the precise function(s) of CRISP2 remains to be determined. Recent data have shown that the CRISP domain of the mouse CRISP2 has the ability to regulate Ca 2C flow through ryanodine receptors (RyR) and to bind to MAP kinase kinase kinase 11 (MAP3K11). To further define the biochemical pathways within which CRISP2 is involved, we screened an adult mouse testis cDNA library using a yeast two-hybrid assay to identify CRISP2 interacting partners. One of the most frequently identified CRISP2-binding proteins was gametogenetin 1 (GGN1). Interactions occur between the ion channel regulatory region within the CRISP2 CRISP domain and the carboxyl-most 158 amino acids of GGN1. CRISP2 does not bind to the GGN2 or GGN3 isoforms. Furthermore, we showed that Ggn1 is a testis-enriched mRNA and the protein first appeared in late pachytene spermatocytes and was up-regulated in round spermatids before being incorporated into the principal piece of the sperm tail where it co-localized with CRISP2. These data along with data on RyR and MAP3K11 binding define the CRISP2 CRISP domain as a protein interaction motif and suggest a role for the GGN1-CRISP2 complex in sperm tail development and/or motility.Reproduction (2008) 135 751-759

Klinefelter syndrome (KS) is a common genetic condition that is currently under-diagnosed. The phenotype is broad, with physical, medical and psychosocial features ranging from mild to severe. When a child is diagnosed with KS, the parents may spend months to years searching for a diagnosis. This study used a qualitative methods approach to explore parents' experiences of having a child with KS and receiving a diagnosis. Fifteen semistructured one-to-one in-depth interviews were conducted to explore their experiences and views. The interviews were then transcribed, coded and thematically analysed. The interviews revealed that parents had diverse experiences related to: the timing of the diagnosis of their child and reasons why their child was investigated for KS; the information that was provided at the time of diagnosis; the supports that were available and the concerns that parents held for the future of their child. The conclusions from this study were that parents' experiences of having a child with KS and receiving a diagnosis were complex and multifaceted. This experience was shaped by the timing of when the diagnosis was received, who provided the diagnosis, what information was provided from health-care professionals and that which parents may have encountered on the internet. The long-term experiences for parents were also impacted by the level of support they received. These findings have implications for the process by which KS is recognised by the health-care community and supports available for families.

Despite increasing knowledge of the natural history of the Klinefelter syndrome spectrum, beneficial interventions and when they should occur, most opportunities are missed due to nondiagnosis. Population screening is arguably the only way of ensuring timely detection of individuals with Klinefelter syndrome. The technologies and structures for such a program already exist. This field now requires a pilot program to further define the risks, benefits and psychosocial and ethical dimensions of screening.

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