16 research outputs found

    Pubertal presentation in seven patients with congenital adrenal hyperplasia due to P450 Oxidoreductase deficiency

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    Context: P450 oxidoreductase (POR) is a crucial electron donor to all microsomal P450 cytochrome (CYP) enzymes including 17α-hydroxylase (CYP17A1), 21-hydroxylase (CYP21A2) and P450 aromatase. Mutant POR causes congenital adrenal hyperplasia with combined glucocorticoid and sex steroid deficiency. P450 oxidoreductase deficiency (ORD) commonly presents neonatally, with disordered sex development in both sexes, skeletal malformations, and glucocorticoid deficiency. \ud \ud Objective: The aim of the study was to describe the clinical and biochemical characteristics of ORD during puberty. \ud \ud Design: Clinical, biochemical, and genetic assessment of seven ORD patients (five females, two males) presenting during puberty was conducted. \ud \ud Results: Predominant findings in females were incomplete pubertal development (four of five) and large ovarian cysts (five of five) prone to spontaneous rupture, in some only resolving after combined treatment with estrogen/progestin, GnRH superagonists, and glucocorticoids. Pubertal development in the two boys was more mildly affected, with some spontaneous progression. Urinary steroid profiling revealed combined CYP17A1 and CYP21A2 deficiencies indicative of ORD in all patients; all but one failed to mount an appropriate cortisol response to ACTH stimulation indicative of adrenal insufficiency. Diagnosis of ORD was confirmed by direct sequencing, demonstrating disease-causing POR mutations. \ud \ud Conclusion: Delayed and disordered puberty can be the first sign leading to a diagnosis of ORD. Appropriate testosterone production during puberty in affected boys but manifest primary hypogonadism in girls with ORD may indicate that testicular steroidogenesis is less dependent on POR than adrenal and ovarian steroidogenesis. Ovarian cysts in pubertal girls may be driven not only by high gonadotropins but possibly also by impaired CYP51A1-mediated production of meiosis-activating sterols due to mutant POR

    Autocrine androgen action is essential for Leydig cell maturation and function, and protects against late-onset Leydig cell apoptosis in both mice and men

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    Leydig cell number and function decline as men age, and low testosterone is associated with all “Western” cardio-metabolic disorders. However, whether perturbed androgen action within the adult Leydig cell lineage predisposes individuals to this late-onset degeneration remains unknown. To address this, we generated a novel mouse model in which androgen receptor (AR) is ablated from ∌75% of adult Leydig stem cell/cell progenitors, from fetal life onward (Leydig cell AR knockout mice), permitting interrogation of the specific roles of autocrine Leydig cell AR signaling through comparison to adjacent AR-retaining Leydig cells, testes from littermate controls, and to human testes, including from patients with complete androgen insensitivity syndrome (CAIS). This revealed that autocrine AR signaling is dispensable for the attainment of final Leydig cell number but is essential for Leydig cell maturation and regulation of steroidogenic enzymes in adulthood. Furthermore, these studies reveal that autocrine AR signaling in Leydig cells protects against late-onset degeneration of the seminiferous epithelium in mice and inhibits Leydig cell apoptosis in both adult mice and patients with CAIS, possibly via opposing aberrant estrogen signaling. We conclude that autocrine androgen action within Leydig cells is essential for the lifelong support of spermatogenesis and the development and lifelong health of Leydig cells.—O’Hara, L., McInnes, K., Simitsidellis, I., Morgan, S., Atanassova, N., Slowikowska-Hilczer, J., Kula, K., Szarras-Czapnik, M., Milne, L., Mitchell, R. T., Smith, L. B. Autocrine androgen action is essential for Leydig cell maturation and function, and protects against late-onset Leydig cell apoptosis in both mice and men

    Familial X/Y translocations associated with variable sexual phenotype

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    True hermaphroditism, defined clinically as the presence of both male and female gonadal tissue in the same individual usually accompanied by ambiguous genitalia, is a genetically heterogeneous condition.1–3 Less than 10% of true hermaphrodites with an apparent 46,XX constitution are SRY-positive, usually resulting from translocation between Xp and Yp.4–7 Previously we described two true hermaphrodites (AK and PG) of Polish origin, both of whom carry X/Y translocations with SRY translocated onto distal Xp.6 Here, we show that the same X/Y translocation is also carried by fertile male and female relatives of the hermaphrodite probands, and identify varying sexual phenotype in individuals with the same chromosome abnormality. <br/

    Variability of sexual phenotype in 46,XX(SRY+) patients: the influence of spreading X inactivation versus position effects

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    During male meiosis the X and Y chromosomes pair along much of their length, with a single obligatory recombination event usually occurring in the pseudo-autosomal region (PAR) at the tip of Xp and Yp, thus maintaining identity of the sex chromosome PARs.Occasionally illegitimate crossover occurs outside the PAR, resulting in the transfer of Y specific sequences onto the X chromosome. Such translocations between distal Xp and Yp occur relatively frequently, resulting in the generation of 46,XX individuals, the majority of whom display an overtly male phenotype due to transfer of the SRY gene onto the short arm of the paternal X. However, a small number of Yp translocations are associated with hermaphroditism, defined as the presence of both testicular and ovarian tissue in the same individual

    Treatment for 24 months with recombinant human GH has a beneficial effect on bone mineral density in young adults with childhood-onset GH deficiency

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    OBJECTIVE: Discontinuation of growth hormone (GH) therapy on completion of linear growth may adversely affect bone mineral density (BMD) in young adults with childhood-onset GH-deficiency (GHD). In the present study, we analyzed the impact of GH treatment on bone in young adults with GHD. METHODS: BMD at the lumbar spine (L2-L4), total hip, and total body was measured at baseline and after 24 months in a cohort of young adults (18-25 years; n=160) with severe GHD treated with GH during childhood who were randomized to GH (n=109) or no treatment (n=51) in a multicenter, multinational, open-label study. GH starting doses (0.2 mg/day (males), 0.4 mg/day (females)) were increased after 1 month to 0.6 mg/day (males) and 0.9 mg/day (females) and then to 1.0 mg/day (males) and 1.4 mg/day (females) at 3 months for the remainder of the study. RESULTS: After 24 months, lumbar spine BMD had increased significantly more in GH-treated patients than in controls (6 vs 2%; estimated treatment difference; 3.5% (95% confidence interval, 1.52-5.51) P<0.001). GH also had a significant positive effect on total hip BMD (P=0.015). Total body BMD was unchanged from baseline (P=0.315). CONCLUSIONS: In young adults treated for childhood-onset GHD, there is a beneficial effect of continued GH treatment on BMD in adult life. Twenty-four months of GH treatment in these young adults was associated with an estimated 3.5% greater increase in BMD of the lumbar spine compared with controls

    Mutant luteinizing hormone receptors in a compound heterozygous patient with complete Leydig cell hypoplasia: abnormal processing causes signaling deficiency

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    Over the past 5 yr several inactivating mutations in the LH receptor gene have been demonstrated to cause Leydig cell hypoplasia, a rare autosomal recessive form of male pseudohermaphroditism. Here, we report the identification of two new LH receptor mutations in a compound heterozygous case of complete Leydig hypoplasia and determine the cause of the signaling deficiency at a molecular level. On the paternal allele of the patient we identified in codon 343 a T to A transversion that changes a conserved cysteine in the hinge region of the receptor to serine (C343S); on the maternal allele a T to C transition causes another conserved cysteine at codon 543 in trans-membrane segment 5 to be altered to arginine (C543R). Both of these mutant receptors are completely devoid of hormone-induced cAMP reporter gene activation. Using Western blotting of expressed LH receptor protein with a hemagglutinin tag, we further show that despite complete absence of total and cell surface hormone binding, protein levels of both mutant LH receptors are only moderately affected

    Supplementary Material for: A Case of Two Sisters Suffering from 46,XY Gonadal Dysgenesis and Carrying a Mutation of a Novel Candidate Sex-Determining Gene STARD8 on the X Chromosome

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    Identification of novel genes involved in sexual development is crucial for understanding disorders of sex development (DSD). Here, we propose a member of the START domain family, the X chromosome<i> STARD8,</i> as a DSD candidate gene. We have identified a missense mutation of this gene in 2 sisters with 46,XY gonadal dysgenesis, inherited from their heterozygous mother. Gonadal tissue of one of the sisters contained Leydig cells overloaded with cholesterol droplets, i.e., structures previously identified in 46,XY DSD patients carrying mutations in the <i>STAR</i> gene encoding another START domain family member, which is crucial for steroidogenesis. Based on the phenotypes of our patients, we propose a dual role of <i>STARD8 </i>in sexual development, namely in testes determination and testosterone synthesis. However, further studies are needed to confirm the involvement of <i>STARD8</i> in sexual development
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