Identification of a novel mutation in exon 1 of androgen receptor gene in an azoospermic patient with mild androgen insensitivity syndrome: case report and literature review

OBJECTIVE

To report a case of an azoospermic subject with mild androgen insensitivity syndrome (MAIS) and review the relevant literature.

DESIGN

Case report.

SETTING

Academic research hospital.

PATIENT(S)

A 49-year-old man with undermasculinized features and a history of cryptorchidism and azoospermia.

INTERVENTION(S)

Hormonal evaluation and genetic testing of the androgen receptor gene (AR).

MAIN OUTCOME MEASURE(S)

Hormonal levels and sequence chromatogram of the proband and his mother.

RESULT(S)

We found total T in the normal range and high levels of gonadotropins. Karyotype was 46,XY. Genetic testing identified a novel mutation of exon 1 of AR, which resulted in an alanine to serine substitution in the transactivation domain at codon 240 (A240S). Fourteen other mutations of exon 1 of AR have been associated with MAIS to date.

CONCLUSION(S)

The novel mutation A240S of AR is involved in MAIS, a syndrome associated with azoospermia.

Improvements in human sperm quality by long-term in vitro co-culture with isolated porcine Sertoli cells

BACKGROUND

Spermatogenesis is a complex process where spermatogonial germ cells become spermatozoa with the indispensable support of Sertoli cells (SCs), which provide 'ad hoc' structural and nutritional support. Unfortunately, for most sperm dysfunctions, no therapies are yet available except assisted reproductive technologies (ART) that are based on the use of different culture media to preserve sperm in vitro. However, sperm culture is only possible for short periods of time, since long-term culture would invariably and irreversibly damage the cells with negative impact on their fertilization potential.

METHODS

Fresh sperm cells (5 ml of 20 × 10(6)/ml) were co-cultured with SCs layers, derived from prepubertal pig testes or incubated in cell free SC medium or BWW (Biggers, Whitten and Whittingham) medium for 2, 4 or 7 days. Sperm viability, motility, mitochondrial status, DNA fragmentation, chromatin integrity, intracellular calcium and acrosome status were assessed after every co-culture or incubation time, but capacitation and induction of acrosome reaction (AR) with progesterone was only evaluated after 7 days.

RESULTS

SCs layers derived from prepubertal pig testes (co-culture of sperm and SC feeder, CCSCF) were able to preserve normal sperm viability, motility and normal mitochondrial function, after 7 days of culture; CCSCF did not induce AR or hyperactivation of spermatozoa, keeping the sperm in a quiescent state for 7 days of culture. Nevertheless, the sperm were readily able to initiate AR after stimulation with progesterone.

CONCLUSIONS

CCSCF maintained good sperm viability and motility for 7 days. This approach could improve retention of sperm viability and motility during ART procedures and maintain sperm viability, during transfer between two distant Centres, avoiding the need for cryopreservation.

Azoospermia in a man with a constitutional ring 22 chromosome

A mosaic ring chromosome 22 (mos 46,XY,r(22)[93]/45,XY,-22[7]) was found in an euploid azoospermic otherwise phenotypically normal individual. Testicular cytological analysis showed hypospermatogenesis with a complete spermatogonial arrest. The majority of subjects with constitutional r(22) are dysmorphic and mentally retarded due to deletion of a sizable segment of the chromosome 22q. Only a few cases of r(22) chromosome are known in which deletion of the very distal telomeric regions is associated with unremarkable phenotype and fertility, both in males and females. The present patient is the first example of male infertility associated with this cytogenetic anomaly. It is likely that infertility arose from a mechanical block of meiosis, resulting from pairing failure of chromosomes 22, similarly to azoospermia occurring in few known males with r(21) chromosomes.

Retraction: Expression of phosphodiesterase type 5A in human spermatozoa and influence of its inhibition on motility and functional sperm parameters

The paper entitled "Expression of phosphodiesterase type 5A in human spermatozoa and influence of its inhibition on motility and functional sperm parameters" by C. Foresta et al, which was published online on 1 July 2010, has been withdrawn at the authors' request.

Effect of vardenafil on endothelial progenitor cells in hypogonadotrophic hypogonadal patients: role of testosterone treatment

CONTEXT

Endothelial progenitor cells (EPCs) are bone marrow-derived cells required for endothelial repair. Circulating EPC concentration is low in conditions characterized by endothelial dysfunction but their number can be increased by treatment with phosphodiesterase-5 (PDE5) inhibitors. EPCs are also reduced in hypogonadal men and testosterone (T) treatment restores their concentration.

OBJECTIVE

To evaluate the relationship between the effect of PDE5 inhibitors and T on EPCs, we analysed the acute effect of vardenafil on the number of EPCs in hypogonadotrophic hypogonadal (HH) patients, before and after T treatment.

DESIGN AND SETTING

A case-control study at a university andrology centre.

PATIENTS

Fifteen HH subjects and 25 aged-matched controls.

MAIN OUTCOME MEASURES

The number of circulating EPCs and progenitor cells (PCs) in HH patients was evaluated after acute vardenafil administration at baseline and after 6 months of T supplementation.

RESULTS

At baseline, HH men had significantly lower numbers of PCs and EPCs with respect to controls and vardenafil administration had no effect on the number of these cells. After 6 months of T treatment, all HH patients were eugonadal. With respect to baseline, PCs and EPCs were significantly higher and reached the levels observed in controls. Vardenafil administration in HH men at the end of T treatment induced a significant increase in PCs and EPCs in a manner similar to that in controls.

CONCLUSIONS

This study showed that normal T levels are necessary to restore the responsiveness of EPCs to PDE5 inhibitors, suggesting that T positively modulates PDE5 in bone marrow.

Mutations in INSL3 and RXFP2 genes in cryptorchid boys

Mutations in the INSL3 and RXFP2 genes have been associated with human cryptorchidism but with contrasting data. We analyzed the frequency of mutations in these genes in 600 newborns with cryptorchidism (396 unilateral and 204 bilateral) and 300 noncryptorchid subjects. We found five RXFP2 mutations in five bilateral cryptorchid boys, one INSL3 mutation in a unilateral cryptorchid boy, and one INSL3 mutation in a boy with unilateral cryptorchidism at birth and spontaneous descent during the first month of life. Overall, the frequency of INSL3 and RXFP2 mutations was therefore 7/600 at birth (1.2%) and 7/303 (2.3%) in persistent cryptorchid boys, with a higher prevalence of bilateral forms (5/120, 4.2%). No mutations were found in controls. This study confirmed the association between INSL3 and RXFP2 gene mutations and human cryptorchidism.

Genetic alterations associated with cryptorchidism

CONTEXT

Cryptorchidism is the most frequent congenital birth defect in male children and represents an important risk factor for infertility and testicular cancer. Major regulators of testicular descent are the hormones insulin-like factor 3 (INSL3) and testosterone, and disruption of these pathways might cause cryptorchidism.

OBJECTIVE

To determine the frequency of genetic alterations in cryptorchidism.

DESIGN AND SETTING

Case-control study in 2 departments of pediatric surgery in Italy between January 2003 and March 2005.

PATIENTS

Six hundred male infants with cryptorchidism. Boys were followed up for 2 to 3 years (through January 2008) and orchidopexy was performed in those who were persistently cryptorchid. We analyzed 300 noncryptorchid male children aged 1 to 4 years as controls.

MAIN OUTCOME MEASURES

Karyotype anomalies and INSL3, INSL3 receptor, and androgen receptor gene mutations.

RESULTS

The frequency of genetic alterations in boys with cryptorchidism was low (17/600 [2.8%; 95% confidence interval {CI}, 1.7%-4.5%]) and was significantly higher in participants with persistent cryptorchidism (16/303 [5.3%; 95% CI, 3.0%-8.4%]; P = .001) and those with bilateral cryptorchidism (10/120 [8.3%; 95% CI, 4.1%-14.8%]; P = .001) than in controls (1/300 [0.3%; 95% CI, 0.1%-0.8%]). Boys with persistent cryptorchidism had a 17-fold greater odds of having a genetic alteration (odds ratio, 16.7; 95% CI, 2.2-126.5). The most common genetic findings in those with cryptorchidism were 8 cases of Klinefelter syndrome and 5 cases of mutations in the INSL3 receptor gene. Genetic alterations were not found in boys with low birth weight or low gestational age, who had frequent spontaneous descent of the testes.

CONCLUSION

In a small percentage of the study population, there was a statistically significant association between bilateral and persistent cryptorchidism and genetic alterations, including Klinefelter syndrome and INSL3 receptor gene mutations.

Role of hormones, genes, and environment in human cryptorchidism

Cryptorchidism is the most frequent congenital birth defect in male children (2-4% in full-term male births), and it has the potential to impact the health of the human male. In fact, although it is often considered a mild malformation, it represents the best-characterized risk factor for reduced fertility and testicular cancer. Furthermore, some reports have highlighted a significant increase in the prevalence of cryptorchidism over the last few decades. Etiology of cryptorchidism remains for the most part unknown, and cryptorchidism itself might be considered a complex disease. Major regulators of testicular descent from intraabdominal location into the bottom of the scrotum are the Leydig-cell-derived hormones testosterone and insulin-like factor 3. Research on possible genetic causes of cryptorchidism has increased recently. Abundant animal evidence supports a genetic cause, whereas the genetic contribution to human cryptorchidism is being elucidated only recently. Mutations in the gene for insulin-like factor 3 and its receptor and in the androgen receptor gene have been recognized as causes of cryptorchidism in some cases, but some chromosomal alterations, above all the Klinefelter syndrome, are also frequently involved. Environmental factors acting as endocrine disruptors of testicular descent might also contribute to the etiology of cryptorchidism and its increased incidence in recent years. Furthermore, polymorphisms in different genes have recently been investigated as contributing risk factors for cryptorchidism, alone or by influencing susceptibility to endocrine disruptors. Obviously, the interaction of environmental and genetic factors is fundamental, and many aspects have been clarified only recently.

Mutations in dynein genes in patients affected by isolated non-syndromic asthenozoospermia

BACKGROUND

Asthenozoospermia (AZS) is a common cause of male infertility characterized by reduced forward motility (WHO grade A+B sperm motility <50% or A < 25%) or absent sperm motility in fresh ejaculate. AZS may exist as an isolated disorder, in combination with other sperm anomalies or as part of a syndromic association. Up to date, only a few genes, constituting the cilia/flagella structure, have been associated with isolated AZS in humans, whereas several other genes are known to be involved in syndromic form of AZS, including primary ciliary dyskinesia (PCD) and Kartagener syndrome (KS). Axonemal ultrastructural defects, including absent or shortened arms of dyneins, can be found in >50% of PCD/KS patients. Approximately 90% of KS male patients are affected by AZS. The majority of KS patients can be ascribed to dynein genes mutations.

METHODS

Mutation screening of DNAI1, DNAH5 and DNAH11 genes was performed in 90 patients with isolated non-syndromic AZS and 200 controls.

RESULTS

We found three mutations (one in each gene) specifically associated with AZS in seven patients (7.8%). Mutations are inherited from the mothers and may be found in familial clusters. No ultrastructural axonemal anomaly was detected in sperm.

CONCLUSIONS

We report for the first time a possible association between mutations in dynein genes and isolated AZS. Male carriers of the mutations always exhibit AZS, whereas female carriers manifest no alterations in either fertility or pulmonary clearance.

Detailed functional studies on androgen receptor mild mutations demonstrate their association with male infertility

CONTEXT

Mutations in the androgen receptor (AR) gene can cause the androgen insensitivity syndrome (AIS). For complete and severe partial AIS, well-characterized in vitro functional assays can be used for genotype-phenotype correlation; however, for mild forms of AIS, as associated with male infertility, experimental evidence is scarce or lacking. In particular, optimal in vitro functional tests informative about the genotype-phenotype relation have not been described.

OBJECTIVE

The objective of this study was to investigate the association among genotype and phenotype for AR mutations found in infertile males by conventional functional assays and additional in-depth studies performed with several gene reporters.

DESIGN

To this aim, we selected four AR missense mutations associated with isolated male infertility (L547F and two novel mutations A474V and S650G) or partial AIS (Y571H). After introduction of the specific mutations in AR expression plasmid, we performed classical in vitro studies (Western immunoblotting, electrophoretic mobility shift assay, hormone-response curves) and transactivation assays with different reporter constructs (MMTV, Sc-ARU-TK, TAT-GRE- 2X, Slp-ARU-TK and PEM).

RESULTS AND CONCLUSIONS

Our results showed that standard functional tests provide sufficient information only for severe AR mutations, whereas for AR mutations found in mild AIS patients with male infertility, only an extensive analysis with different in vitro systems, and in particular with PEM promoter, can give information on the functionality of the AR and therefore on the pathogenicity of the mutations and on genotype-phenotype correlation.

Androgens stimulate endothelial progenitor cells through an androgen receptor-mediated pathway

BACKGROUND AND OBJECTIVE

Testosterone (T) treatment has recently been shown to induce an increase in the number of endothelial progenitor cells (EPCs) through a possible effect on bone marrow. Hypogonadotrophic hypogonadal (HH) men have low circulating EPCs that increase significantly after T treatment. Moreover, expression of the androgen receptor (AR) has been demonstrated by immunohistochemistry in these cells, suggesting that T might also have a direct effect on EPC function. In the present study we investigated the expression and function of the AR in human EPCs and the in vitro effect of androgens on EPC function. Design and patients EPCs obtained from healthy male anonymous blood donors were analysed after androgen stimulation with and without AR antagonist administration (flutamide).

RESULTS

Reverse transcriptase polymerase chain reaction (RT-PCR), Western blotting and immunofluorescence analyses demonstrated the expression of AR mRNA and protein in human EPCs. Stimulation of these cells with the synthetic androgen methyltrienolone (R1881) caused AR translocation in the nucleus, suggesting its activation. Colony forming unit (CFU), proliferation and migration assays under different doses of R1881 demonstrated a dose-dependent increase in EPC proliferation, migration and colony formation. All these effects are abolished by flutamide pretreatment.

CONCLUSIONS

This study showed that the increase in the proliferation, migration and colony formation activity of EPCs induced by androgens is an AR-mediated pathway. Androgen exerts these effects at concentrations that are physiologically present in men and therefore further studies are needed to clarify the clinical significance of these effects in normal and pathological conditions.

A possible association of a human tektin-t gene mutation (A229V) with isolated non-syndromic asthenozoospermia: case report

Asthenozoospermia (AZS), characterized by grade A + B sperm motility (as in World Health Organization Guidelines) < or =50% or A <25% in fresh ejaculate, may exist as an isolated disorder, in combination with other sperm anomalies or as part of syndromic association. The majority of syndromic patients can be ascribed to mutations in dynein genes, while, to date, no genes have been described to be associated in humans with non-syndromic, isolated AZS. An interesting family of axonemal proteins, the tektins, has been recently identified in various mammals and they are thought to play a fundamental role in ciliary movement. Recently, the human tektin-t (or h-tekB1 or Tektin-2) gene has been cloned, showing specific expression in flagella of mature sperm. We report the screening of tektin-t gene in 90 isolated non-syndromic AZS patients. We found a heterozygous mutation (A229V) in one patient. Ultrastructural analysis showed anomalies in > or =80% of examined spermatozoa involving axoneme microtubules and mitochondria. Moreover, the viability and mitochondrial function of sperm were altered in the patient with the A229V mutation. This is the first description of human pathology linked to a tektin-family gene, since only murine models are available for these genes.

Hormonal and genetic control of testicular descent

Cryptorchidism has the potential to affect the health of the human male. Although it is often considered a mild malformation, it represents the best-characterized risk factor for reduced fertility and testicular cancer. The aetiology of cryptorchidism remains, for the most part, unknown and cryptorchidism itself might be considered a complex disease. This reflects the intricate mechanisms regulating testicular development and descent from intra-abdominal location into the bottom of the scrotum, involving different anatomical and hormonal factors. Major actors of testicular descent are the Leydig cell-derived hormones testosterone and insulin-like factor 3, even if other factors may play a role. Although considerable evidence exists in animals to support a genetic cause, the genetic contribution to human cryptorchidism is only recently being elucidated. Environmental factors might also contribute to the aetiology of cryptorchidism and its increased incidence in recent years. Mutations in the gene for insulin-like factor 3 and its receptor and in the androgen receptor gene explain a minority of cases of cryptorchidism, but research on genetic polymorphisms that may also influence susceptibility to endocrine disruptors is shedding light on this field.

Oestrogen stimulates endothelial progenitor cells via oestrogen receptor-alpha

CONTEXT

Oestrogens play an important protective role on the vascular system. The endothelial cell layer is a direct target for these hormones, and expresses at least two oestrogen receptors, ER-alpha and ER-beta. Recent studies have shown that vascular healing is significantly modulated by circulating bone marrow-derived cells. A subset of these stem cells, endothelial progenitor cells (EPCs), have recently been described as a population of pluripotent cells within the peripheral blood capable of differentiating into endothelial cells.

OBJECTIVE

In the present study we investigated the expression of ER-alpha and ER-beta on human EPCs and the effect that oestrogens have on the function of EPCs in vitro.

METHODS

EPCs were isolated and cultured from healthy donors. RT-PCR, western blotting and immunohistochemistry were used to assess expression of ER-alpha and ER-beta. Proliferation and CFU assays were used to assess the response of EPCs to different doses of 17,beta-oestradiol.

MAIN OUTCOME MEASURES

Expression of ER-alpha and ER-beta in EPCs, and the effect of 17,beta-oestradiol on proliferation of EPCs.

RESULTS

Human EPCs express ER-alpha mRNA and protein. 17,beta-oestradiol increases proliferation of EPCs and CFU in a dose-dependent manner.

CONCLUSIONS

Human EPCs express ER-alpha but not ER-beta, and oestrogens can stimulate the proliferation of these cells in vitro. Oestrogens exert these effects at concentrations that are usually reached during stimulation for in vitro fertilization in women, and therefore further studies are needed to clarify the clinical significance of these effects.

Y chromosome haplogroups and susceptibility to testicular cancer

Although in the past decades much progress in testicular cancer (TC) management has been made, little is known about the possible genetic causes and molecular mechanisms involved in its aetiopathogenesis. Some studies on possible contribution of the Y chromosome in TC development have been previously published, but data are not conclusive. In particular, ethnic influence and spermatogenic activity of patients with TC have not been adequately considered in previous studies, although they may represent important confounding factors. The objective of this study is to analyse the contribution of the Y chromosome in testicular germ cell cancer subjects who are well defined at the microgeographical, clinical and seminological level. We analysed Y chromosome classic azoospermia factor (AZF) deletions, partial AZFc deletions and Y haplogroups in 118 sporadic cases of testicular germ cell cancer and 93 microgeographically matched controls. Y chromosome screening failed to identify Y chromosome microdeletions in either cases or controls. Y chromosome haplogroup distribution and frequencies did not differ between cases and controls. Furthermore, no difference was observed when comparing patients with seminoma and non-seminoma, nor when comparing patients with TC with normozoospermia and azoo-oligozoospermia. Our findings combined with data reported so far suggest that classic AZF deletions and partial AZFc deletions are not a frequent cause or risk factor for TC and that different Y haplogroup distribution does not contribute to susceptibility to this tumour.

Male infertility: role of genetic background

Male infertility represents one of the clearest examples of a complex disease with a substantial genetic basis. Numerous male mouse models, mutation screening and association studies reported over the last few years reveal the high prevalence of genetic causes of spermatogenic impairment, accounting for 10-15% of severe male infertility, including chromosomal aberrations and single gene mutations. Natural selection prevents the transmission of mutations causing infertility, but this protective mechanism may be overcome by assisted reproduction techniques. Consequently, the identification of genetic factors is important for appropriate management of the infertile couple. However, a large proportion of infertile males are diagnosed as idiopathic, reflecting poor understanding of the basic mechanisms regulating spermatogenesis and sperm function. Furthermore, the molecular mechanisms underlying spermatogenic damage in cases of genetic infertility (for example Yq microdeletions) are not known. These problems can be addressed only by large scale association studies and testicular or spermatozoal expression studies in well-defined alterations of spermatogenesis. It is conceivable that these studies will have important diagnostic and therapeutic implications in the future. This review discusses the genetic causes of male infertility known to date, the genetic polymorphisms possibly associated with male infertility, and reports novel results of global gene expression profiling of normal human testis by microarray technology.

Expression of the PDE5 enzyme on human retinal tissue: new aspects of PDE5 inhibitors ocular side effects

OBJECTIVE

We tested the effect of two phosphodiesterase type-5 (PDE5) inhibitors, sildenafil and tadalafil, on ophthalmic artery (OA) blood flow velocity and investigated the presence of the PDE5 enzyme on human retinal tissue in comparison with the PDE6 enzyme localization.

METHODS

Using Colour Doppler ultrasonography (CDU) we investigated, in 30 healthy young subjects (27.8 years of age; range, 24.3-33.7 years), the effects of a single oral dose of sildenafil (100 mg), tadalafil (20 mg), and placebo on OA blood flow velocity. Western blot for PDE6 and PDE5 protein expression was performed on frozen samples of human retina, testis, sperm, skin, and corpus cavernosum. Immunohistochemistry was performed on two ocular globes from dead donors.

RESULTS

CDU showed a relationship between the administration of PDE5 inhibitors and OA blood flow velocity modifications in a time-dependent manner. Western blot and immunohistochemical analysis showed PDE6 and PDE5 presence in human retinal tissue and gave a map of its distribution.

CONCLUSION

We demonstrated that (a) tadalafil and sildenafil are able to modify the OA flux in a time-dependent manner; (b) the PDE5 enzyme is expressed on retinal and choroid vasculature (smooth muscle and endothelial cells), on ganglion and bipolar cells; (c) human retinal tissues express the PDE6 enzyme in the rod and cone photoreceptors; (d) visual side effects after PDE5 inhibitors administration may be linked to a specific effect on the PDE5 enzyme; and (e) the PDE5 enzyme may have a physiologic role on ganglion and bipolar cells that need to be further investigated.

Y-chromosome haplogroups and susceptibility to azoospermia factor c microdeletion in an Italian population

BACKGROUND

A limited number of studies aimed at investigating the possible association of Y-chromosome haplogroups with microdeletions of the azoospermia factors (AZFs) or with particular infertile phenotypes, but definitive conclusions have not been attained. The main confounding elements in these association studies are the small sample sizes and the lack of homogeneity in the geographical origin of studied populations, affecting, respectively, the statistical power and the haplogroup distribution.

MATERIALS AND METHODS

To assess whether some Y-chromosome haplogroups are predisposing to, or protecting against, azoospermia factor c (AZFc; b2/b4) deletions, 31 north Italian patients carrying the AZFc b2/b4 microdeletion were characterised for 8 Y-chromosome haplogroups, and compared with the haplogroup frequency shown by a north Italian population without the microdeletion (n = 93).

RESULTS AND DISCUSSION

A significant difference was observed between the two populations, patients with microdeletions showing a higher frequency of the E haplogroup (29.3% vs 9.7%, p<0.01). The geographical homogeneity of the microdeleted samples and of the control population, controlled at microgeographical level, allows the possibility that the geographical structure of the Y genetic variability has affected our results to be excluded.

CONCLUSION

Thus, it is concluded that in the north Italian population Y-chromosome background affects the occurrence of AZFc b2/b4 deletions.

Male infertility and androgen receptor gene mutations: clinical features and identification of seven novel mutations

OBJECTIVE

Androgens and a functioning androgen receptor (AR) are essential for development and maintenance of the male phenotype and spermatogenesis. Consistent with this, mutations in the AR gene cause a variety of defects related to androgen insensitivity, ranging from complete feminization to phenotypic males with infertility. The aim of his study was to analyse the prevalence of AR gene mutations in male infertility and to clarify the genotype-phenotype relation.

DESIGN

Males with infertility were recruited consecutively at the Centre for Male Gamete Cryopreservation at the University of Padova from January 1996 to January 2005.

PATIENTS

One thousand five hundred and seventeen men with < 10 million sperm/ml and 310 age-matched normozoospermic controls.

METHODS

Screening for AR gene mutation was done by DHPLC and sequencing, and reproductive hormone concentrations were measured.

RESULTS

We found 20 mutations in 26 of 1517 patients (1.7%) and no mutations in controls. A high number of mutations localized in exon 1 of the AR gene coding for the transactivation domain of the protein. Of 20 mutations, 7 represent novel mutations. With respect to men without AR mutations, subjects with AR mutations have lower ejaculate volume, higher testosterone levels, higher oestradiol levels, and higher androgen sensitivity index. However, the ranges for these variables were highly overlapping between men with and without AR gene mutations. Also clinical manifestations of AR mutations are not unique and 22 men had only spermatogenic impairment.

CONCLUSIONS

AR gene mutations are quite frequent in unselected infertile men but no specific hormonal or clinical data could be used to preselect patients at risk of mutations.

Paracrine and endocrine roles of insulin-like factor 3

Insulin-like factor 3 (INSL3) is expressed in Leydig cells of the testis and theca cells of the ovary. This peptide affects testicular descent by acting on gubernaculum via its specific receptor leucine-rich repeat-containing G protein-coupled receptor 8 (LGR8). From initial animal data showing the cryptorchid phenotype of Insl3/Lgr8 mutants, an extensive search for mutations in INSL3 and LGR8 genes was undertaken in human patients with cryptorchidism, and a frequency of mutation of 4-5% has been detected. However, definitive proofs of a causative role for some of these mutations are still lacking. More recent data suggest additional paracrine (in the testis and ovary) and endocrine actions of INSL3 in adults. INSL3 circulates at high concentrations in serum of adult males and its production is dependent on the differentiation effect of LH. Therefore, INSL3 is increasingly used as a specific marker of Leydig cell differentiation and function.

Pure trisomy 19p syndrome in an infant with an extra ring chromosome

We report a 12-month-old infant evaluated for severe hypotonia, psychomotor retardation, and facial dysmorphisms, including round face, high prominent forehead, downward slanted palpebral fissures, hypertelorism, short nose, chubby cheeks, long philtrum, anteverted lower lip, low-set asymmetric and dysmorphic ears. Karyotype analysis disclosed an extra mosaic ring chromosome, which included the whole 19p arm. Four additional patients with supernumerary ring 19 chromosomes have been reported, but none of them had pure trisomy 19p.