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Autosomal recessive cutis laxa type I (ARCL type I) is characterized by generalized cutis laxa with pulmonary emphysema and/or vascular complications. Rarely, mutations can be identified in FBLN4 or FBLN5. Recently, LTBP4 mutations have been implicated in a similar phenotype. Studying FBLN4, FBLN5 and LTBP4 in 12 families with ARCL type I, we found bi-allelic FBLN5 mutations in 2 probands, whereas 9 probands harbored biallelic mutations in LTBP4. FBLN5 and LTBP4 mutations cause a very similar phenotype associated with severe pulmonary emphysema, in the absence of vascular tortuosity or aneurysms. Gastro-intestinal and genitourinary tract involvement seems to be more severe in patients with LTBP4 mutations. Functional studies showed that most premature termination mutations in LTBP4 result in severely reduced mRNA and protein levels. This correlated with increased transforming growth factor beta (TGFβ) signaling. However, one mutation, c.4127dupC, escaped nonsense-mediated decay. The corresponding mutant protein (p.Arg1377Alafs*27) showed reduced colocalization with fibronectin, leading to an abnormal morphology of microfibrils in fibroblast cultures, while retaining normal TGFβ signaling. We conclude that LTBP4 mutations cause disease through both loss of function and gain of function mechanisms.

Robertsonian translocations are the most frequent structural chromosomal abnormalities in humans and can affect fertility, with various degrees of sperm alterations in men; or the pregnancy outcome of the carriers. The studies on meiotic segregation of chromosomes in sperm of Robertsonian translocation males find a majority of normal or balanced spermatozoa for the chromosomes related to the translocation (mean 85.42%; range 60–96.60%). Furthermore, recent studies suggest an interchromosomal effect. Studies on spermatozoa from translocation carriers, and in mouse models help the comprehension of the meiotic segregation mechanisms. Results of meiotic segregation analysis in man could be integrated in genetic counselling especially when assisted reproductive technology is required.

Testicular cancer is the most common cancer in young men. Several studies have reported an alteration in semen quality in nonseminoma tumors, but this result has not been confirmed in all of the published data. We performed a retrospective study in a population of 1158 men with testicular cancer who banked sperm between 1999 and 2003 in 11 French Centre d'Etude et de Conservation des Oeufs et du Sperme humain laboratories. Our study evaluated prefreeze and postthaw sperm parameters according to patient medical history, tumor histological type, and disease stage. Pure seminomas were found in 48% of our population. Testicular cancer was generally diagnosed at stage I. In cases of a history of unilateral cryptorchidism, testicular cancer occurred preferentially in the maldescended testis. Semen samples were preferentially collected after orchiectomy. The sperm concentration and total sperm number were significantly lower before orchiectomy in seminomas compared with nonseminoma tumors (P , .001). After orchiectomy, these parameters decreased for nonseminoma tumors and did not vary for seminomas. Semen parameters were more severely impaired for stage III tumors, and when patients had a history of cryptorchidism or when they were less than 20 years of age. Azoospermia was more frequently observed before than after orchiectomy. In this study, we determined that sperm cryobanking should preferentially be performed before orchiectomy and that testicular sperm extraction concurrent with orchiectomy should be used in severe spermatogenesis impairment. Our study highlights that seminomas alter sperm production more significantly than nonseminoma tumors and seem to preferentially impair spermatogenesis in tumor-bearing testes.

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