SF-1/NR5A1 mutations are frequently found in 46,XY DSD individuals (9%) and manifest with a broad phenotype. Testes histology is characteristic for fat accumulation and degeneration over time, similar to findings observed in patients with lipoid congenital adrenal hyperplasia (due to StAR mutations). Genotype-structure-function-phenotype correlation remains elusive.
AR gene mutation is the most frequent cause of 46,XY DSD, with a clearly higher frequency in the complete phenotype. Mutations spread along the whole coding sequence, including exon 1. This series shows that 60% of mutations detected during the period 2002-2009 were novel.
The differential diagnosis of differences or disorders of sex development (DSD) belongs to the most complex fields in medicine. It requires a multidisciplinary team conducting a synoptic and complementary approach consisting of thorough clinical, hormonal and genetic workups. This position paper of EU COST (European Cooperation in Science and Technology) Action BM1303 ‘DSDnet’ was written by leading experts in the field and focuses on current best practice in genetic diagnosis in DSD patients. Ascertainment of the karyotpye defines one of the three major diagnostic DSD subclasses and is therefore the mandatory initial step. Subsequently, further analyses comprise molecular studies of monogenic DSD causes or analysis of copy number variations (CNV) or both. Panels of candidate genes provide rapid and reliable results. Whole exome and genome sequencing (WES and WGS) represent valuable methodological developments that are currently in the transition from basic science to clinical routine service in the field of DSD. However, in addition to covering known DSD candidate genes, WES and WGS help to identify novel genetic causes for DSD. Diagnostic interpretation must be performed with utmost caution and needs careful scientific validation in each DSD case.
Context:The focus of care in disorders of sex development (DSD) is often directed to issues related to sex and gender development. In addition, the molecular etiology remains unclear in the majority of cases.Objective:To report the range of associated conditions identified in the international DSD (I-DSD) Registry.Design, Setting, and Patients:Anonymized data were extracted from the I-DSD Registry for diagnosis, karyotype, sex of rearing, genetic investigations, and associated anomalies. If necessary, clarification was sought from the reporting clinician.Results:Of 649 accessible cases, associated conditions occurred in 168 (26%); 103 (61%) cases had one condition, 31 (18%) had two conditions, 20 (12%) had three conditions, and 14 (8%) had four or more conditions. Karyotypes with most frequently reported associations included 45,X with 6 of 8 affected cases (75%), 45,X/46,XY with 19 of 42 cases (45%), 46,XY with 112 of 460 cases (24%), and 46,XX with 27 of 121 cases (22%). In the 112 cases of 46,XY DSD, the commonest conditions included small for gestational age in 26 (23%), cardiac anomalies in 22 (20%), and central nervous system disorders in 22 (20%), whereas in the 27 cases of 46,XX DSD, skeletal and renal anomalies were commonest at 12 (44%) and 8 (30%), respectively. Of 170 cases of suspected androgen insensitivity syndrome, 19 (11%) had reported anomalies and 9 of these had confirmed androgen receptor mutations.Conclusions:Over a quarter of the cases in the I-DSD Registry have an additional condition. These associations can direct investigators toward novel genetic etiology and also highlight the need for more holistic care of the affected person.
The suppressive therapy with levothyroxine was not effective in reducing nodule sizes in patients with solitary benign thyroid nodules.
SF-1/NR5A1 is a transcriptional regulator of adrenal and gonadal development. NR5A1 disease-causing variants cause disorders of sex development (DSD) and adrenal failure, but most affected individuals show a broad DSD/reproductive phenotype only. Most NR5A1 variants show in vitro pathogenic effects, but not when tested in heterozygote state together with wild-type NR5A1 as usually seen in patients. Thus, the genotype-phenotype correlation for NR5A1 variants remains an unsolved question. We analyzed heterozygous 46,XY SF-1/NR5A1 patients by whole exome sequencing and used an algorithm for data analysis based on selected project-specific DSD- and SF-1-related genes. The variants detected were evaluated for their significance in literature, databases and checked in silico using webtools. We identified 19 potentially deleterious variants (one to seven per patient) in 18 genes in four 46,XY DSD subjects carrying heterozygous NR5A1 disease-causing variants. We constructed a scheme of all these hits within the landscape of currently known genes involved in male sex determination and differentiation. Our results suggest that the broad phenotype in these heterozygous NR5A1 46,XY DSD subjects may well be explained by an oligogenic mode of inheritance, in which multiple hits, individually non-deleterious, may contribute to a DSD phenotype unique to each heterozygous SF-1/NR5A1 individual.
MAMLD1 is thought to cause disordered sex development in 46,XY patients. But its role is controversial because some MAMLD1 variants are also detected in normal individuals, several MAMLD1 mutations have wild-type activity in functional tests, and the male Mamld1-knockout mouse has normal genitalia and reproduction. Our aim was to search for MAMLD1 variations in 108 46,XY patients with disordered sex development, and to test them functionally. We detected MAMDL1 variations and compared SNP frequencies in controls and patients. We tested MAMLD1 transcriptional activity on promoters involved in sex development and assessed the effect of MAMLD1 on androgen production. MAMLD1 expression in normal steroid-producing tissues and mutant MAMLD1 protein expression were also assessed. Nine MAMLD1 mutations (7 novel) were characterized. In vitro, most MAMLD1 variants acted similarly to wild type. Only the L210X mutation showed loss of function in all tests. We detected no effect of wild-type or MAMLD1 variants on CYP17A1 enzyme activity in our cell experiments, and Western blots revealed no significant differences for MAMLD1 protein expression. MAMLD1 was expressed in human adult testes and adrenals. In conclusion, our data support the notion that MAMLD1 sequence variations may not suffice to explain the phenotype in carriers and that MAMLD1 may also have a role in adult life.
Serum levels of leptin are decreased in underweight AN patients and increase with weight restoration. To assess the relationship of decreased leptin levels with other hormonal abnormalities in AN and to evaluate the possible role of increasing leptin levels, alone or in combination with other hormones, in the resumption of menses that accompanies weight gain, we studied crosssectionally sixty-five consecutively enrolled AN patients. Subjects were divided in three groups: (I) underweight and amenorrheic; (II) weight-recovered but still amenorrheic; and (III) weight-recovered and eumenorrheic women. Patients in group I had decreased BMI, serum leptin, estradiol (E2), insulin-like growth factor 1 (IGF-1) and urinary growth hormone (GH) levels and increased sex hormone-binding globulin (SHBG) levels, compared to AN patients in groups II and III. Moreover, although no differences in leptin levels or BMI were observed between amenorrheic and eumenorrheic weight-recovered patients (groups II and III), free E2 and GH levels were higher (PϽ0.02) in weight-recovered, eumenorrheic women. Thus, it appears that leptin is a necessary, but not a sufficient, factor for the resumption of menses in AN patients.Anorexia nervosa (AN) is a disorder characterized by abnormally low body weight, amenorrhea and specific psychopathologic features including intense fear of gaining weight and an abnormal way one's body weight, size or shape is perceived. [1][2][3] In addition, patients with AN have several endocrine abnormalities. These include abnormalities of the growth hormone (GH)-insulin-like growth factor 1 (IGF-1) axis 4,5 as well as decreased serum estrogen levels due to dysfunction of the hypothalamic-pituitary-gonadal axis 6,7 that leads to amenorrhea, anovulation, vaginal and breast atrophy.2,3 Based on the notion that initiation and maintenance of menstrual cycles would require the presence of a minimum amount of body fat to ensure adequate energy stores needed to sustain pregnancy and provide nutrition to the fetus, it has been previously proposed that the abnormal hypothalamicpituitary-gonadal function in anorexia nervosa could be the result of excessive weight loss. 8,9 Until recently this hypothesis remained unproven however, since the potential molecular link between decreased adipose stores and the hypothalamic-pituitary-gonadal axis had not been identified.Our understanding of the interaction between adipose stores and the reproductive system was recently greatly advanced by the discovery of leptin, 10 an adipocyte secreted hormone, whose circulating levels are directly associated with the amount of energy stored as fat. Leptin is the signal by which information about the amount of energy stores is conveyed to the brain, and thus, influences food intake and energy expenditure. 11In addition, a much broader spectrum of activities for this hormone has been recently suggested.11,12 More specifically, it has been proposed that leptin regulates several neuroendocrine axes, including the hypothalamic-pituitary-gonadal axis. 11...
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