Critical Points in the Management of Pseudohypoaldosteronism Type 1

Pseudohypoaldosteronism type 1 (PHA-1, MIM #264350) is caused by defective transepithelial sodium transport. Affected patients develop life-threatening neonatal-onset salt loss, hyperkalemia, acidosis, and elevated aldosterone levels due to end-organ resistance to aldosterone. In this report, we present a patient diagnosed as PHA-1 who had clinical and laboratory findings compatible with the diagnosis and had genetically proven autosomal recessive PHA-1. The patient received high doses of sodium supplementation and potassium-lowering therapies; however, several difficulties were encountered in the management of this case. The aim of this presentation was to point out the potential pitfalls in the treatment of such patients in the clinical practice and to recommend solutions

Androgen receptor mutations are associated with altered epigenomic programming as evidenced by HOXA5 methylation

Male external genital differentiation is accompanied by implementation of a long-term, male-specific gene expression pattern indicating androgen programming in cultured genital fibroblasts. We hypothesized the existence of an epigenetic background contributing to this phenomenon. DNA methylation levels in 2 normal scrotal fibroblast strains from 46,XY males compared to 2 labia majora fibroblast strains from 46,XY females with complete androgen insensitivity syndrome (AIS) due to androgen receptor (AR) mutations were analyzed by Illumina GoldenGate methylation arrays®. Results were validated with pyrosequencing in labia majora fibroblast strains from fifteen 46,XY patients and compared to nine normal male scrotal fibroblast strains. HOXA5 showed a significantly higher methylation level in complete AIS. This finding was confirmed by bisulfite pyrosequencing of 14 CpG positions within the HOXA5 promoter in the same strains. Extension of the 2 groups revealed a constant low HOXA5 methylation pattern in the controls in contrast to a highly variable methylation pattern in the AIS patients. HOXA5 represents a candidate gene of androgen-mediated promoter methylation. The constantly low HOXA5 DNA methylation level of normal male scrotal fibroblast strains and the frequently high methylation levels in labia majora fibroblast strains in AIS indicate for the first time that androgen programming in sexual differentiation is not restricted to global gene transcription but also occurs at the epigenetic level

Neonatal screening: identification of children with 11β-hydroxylase deficiency by second-tier testing

21-Hydroxylase deficiency (21-OHD) is the target disease of newborn screening for congenital adrenal hyperplasia (CAH). We describe the additional detection of patients suffering from 11β-hydroxylase deficiency (11-OHD) by second-tier testing.Over a period of 5 years, screening for CAH was done in a total of 986,098 newborns by time-resolved immunoassay (DELFIA®) for 17α-hydroxyprogesterone (17-OHP). Positive samples were subsequently analyzed in an LC-MS/MS second-tier test including 17-OHP, cortisol, 11-deoxycortisol, 4-androstenedione and 21-deoxycortisol.In addition to 78 cases of 21-OHD, 5 patients with 11-OHD were identified. Diagnostic parameters were a markedly elevated concentration of 11-deoxycortisol in the presence of a low level of cortisol. Androstenedione was also increased. In contrast to 21-OHD, concentrations of 21-deoxycortisol were normal.Steroid profiling in newborn blood samples showing positive results in immunoassays for 17-OHP allows for differentiating 21-OHD from 11-OHD. This procedure may not detect all cases of 11-OHD in the newborn population because there may be samples of affected newborns with negative results for 17-OHP in the immunoassay

Congenital Lipoid Adrenal Hyperplasia: Functional Characterization of Three Novel Mutations in the STAR Gene

AbstractContext: The steroidogenic acute regulatory protein (StAR) has been shown to be essential for steroidogenesis by mediating cholesterol transfer into mitochondria. Inactivating StAR mutations cause the typical clinical picture of congenital lipoid adrenal hyperplasia.Objective: The objective of the investigation was to study the functional and structural consequences of three novel StAR mutations (p.N148K in an Italian patient; p.P129fs and p.Q128R in a Turkish patient).Methods and Results: Transient in vitro expression of the mutant proteins together with P450 side-chain cleavage enzyme, adrenodoxin, and adrenodoxin reductase yielded severely diminished cholesterol conversion of the p.N148K mutant, the combined p.P129fs and p.Q128R mutant, and the p.P129fs mutant by itself. The p.Q128R mutant led to a higher cholesterol conversion than the wild-type StAR protein. As derived from three-dimensional protein modeling, the residue N148 is lining the ligand cavity of StAR. A positively charged lysine residue at position 148 disturbs the hydrophobic cluster formed by the α4-helix and the sterol binding pocket. The frame shift mutation p.P129fs truncates the StAR protein. Residue p.Q128 is situated at the surface of the molecule and is not part of any functionally characterized region of the protein.Conclusion: The mutations p.N148K and p.P129fs cause adrenal insufficiency in both cases and lead to a disorder of sex development with complete sex reversal in the 46, XY case. The mutation p.Q128R, which is not relevant for the patient's phenotype, is the first reported variant showing a gain of function. We speculate that the substitution of hydrophilic glutamine with basic arginine at the surface of the molecule may accelerate cholesterol transfer

17α-hydroxylase deficiency diagnosed in early infancy caused by a novel mutation of the CYP17A1 Gene

Mutations of the CYP17A1 gene cause 17α-hydroxylase deficiency (17OHD) resulting in 46,XY disorder of sex development, hypertension, hypokalemia and absent pubertal development. It is a rare, autosomal recessive form of congenital adrenal hyperplasia (CAH).We report on a neonate with prenatally determined 46,XY karyotype. At 20 weeks of gestation, lack of development of male external genitalia was noticed. A phenotypically female child was born at 41 weeks of gestation.Postnatal ultrasound revealed testes in both labia majora, an absence of uterus and normal adrenal glands. Steroid hormone analysis in serum revealed low basal levels of cortisol, testosterone and androstenedione in the presence of massively elevated corticosterone at the age of 2 weeks. The urinary steroid profile from spot urine showed excessive excretion of 17-desoxysteroids, decreased glucocorticoid metabolites and absent C19 steroids, thus proving 17OHD. Molecular analysis identified a novel mutation of the CYP17A1 gene: c.896T>A (p.I299N) in exon 5. Substitution with hydrocortisone was started. The child is raised as a girl and is developing well so far.Herein, we report the unusually early diagnosis of a newborn with the rare CAH form of 17OHD allowing an early start of treatment

Intrinsic androgen-dependent gene expression patterns revealed by comparison of genital fibroblasts from normal males and individuals with complete and partial androgen insensitivity syndrome

<p>Abstract</p> <p>Background</p> <p>To better understand the molecular programs of normal and abnormal genital development, clear-cut definition of androgen-dependent gene expression patterns, without the influence of genotype (46, XX vs. 46, XY), is warranted. Previously, we have identified global gene expression profiles in genital-derived fibroblasts that differ between 46, XY males and 46, XY females with complete androgen insensitivity syndrome (CAIS) due to inactivating mutations of the androgen receptor (AR). While these differences could be due to cell autonomous changes in gene expression induced by androgen programming, recent work suggests they could also be influenced by the location from which the fibroblasts were harvested (topology). To minimize the influence of topology, we compared gene expression patterns of fibroblasts derived from identical urogenital anlagen: the scrotum in normally virilized 46, XY males and the labia majora from completely feminized 46, XY individuals with CAIS.</p> <p>Results</p> <p>612 transcripts representing 440 unique genes differed significantly in expression levels between scrotum and CAIS labia majora, suggesting the effects of androgen programming. While some genes coincided with those we had identified previously (TBX3, IGFBP5, EGFR, CSPG2), a significant number did not, implying that topology had influenced gene expression in our previous experiments. Supervised clustering of gene expression data derived from a large set of fibroblast cultures from individuals with partial AIS revealed that the new, topology controlled data set better classified the specimens.</p> <p>Conclusion</p> <p>Inactivating mutations of the AR, in themselves, appear to induce lasting changes in gene expression in cultured fibroblasts, independent of topology and genotype. Genes identified are likely to be relevant candidates to decipher androgen-dependent normal and abnormal genital development.</p

Multiplex ligation-dependent probe amplification analysis of the NR0B1(DAX1) locus enables explanation of phenotypic differences in patients with X-linked congenital adrenal hypoplasia

BACKGROUND/AIM:X-linked adrenal hypoplasia congenita (AHC) is a rare disorder characterized by primary adrenal insufficiency and hypogonadic hypogonadism. It is caused by deletions or point mutations of the NR0B1 gene, on Xp21. AHC can be associated with glycerol kinase deficiency, Duchenne muscular dystrophy and mental retardation (MR), as part of a contiguous gene deletion syndrome. A synthetic probe set for multiplex ligation-dependent probe amplification analysis was developed to confirm and characterize NR0B1 deletions in patients with AHC and to correlate their genotypes with their divergent phenotypes. RESULTS:In 2 patients, isolated AHC was confirmed, while a patient at risk for metabolic crisis was revealed as the deletion extends to the GK gene. A deletion extending to IL1RAPL1 was confirmed in both patients showing MR. Thus, a good genotype-phenotype correlation was confirmed. CONCLUSIONS:Multiplex ligation-dependent probe amplification analysis is a valuable tool to detect NR0B1 and contiguous gene deletions in patients with AHC. It is especially helpful for IL1RAPL1 deletion detection as no clinical markers for MR are available. Furthermore, multiplex ligation-dependent probe amplification has the advantage to identify female carriers that, depending on the deletion extension, have a high risk of giving birth to children with MR, AHC, glycerol kinase deficiency and Duchenne muscular dystrophy

Androgen Receptor Function Links Human Sexual Dimorphism to DNA Methylation

Sex differences are well known to be determinants of development, health and disease. Epigenetic mechanisms are also known to differ between men and women through X-inactivation in females. We hypothesized that epigenetic sex differences may also result from sex hormone functions, in particular from long-lasting androgen programming. We aimed at investigating whether inactivation of the androgen receptor, the key regulator of normal male sex development, is associated with differences of the patterns of DNA methylation marks in genital tissues. To this end, we performed large scale array-based analysis of gene methylation profiles on genomic DNA from labioscrotal skin fibroblasts of 8 males and 26 individuals with androgen insensitivity syndrome (AIS) due to inactivating androgen receptor gene mutations. By this approach we identified differential methylation of 167 CpG loci representing 162 unique human genes. These were significantly enriched for androgen target genes and low CpG content promoter genes. Additional 75 genes showed a significant increase of heterogeneity of methylation in AIS compared to a high homogeneity in normal male controls. Our data show that normal and aber

Guidelines for the Development of Comprehensive Care Centers for Congenital Adrenal Hyperplasia: Guidance from the CARES Foundation Initiative

Patients with rare and complex diseases such as congenital adrenal hyperplasia (CAH) often receive fragmented and inadequate care unless efforts are coordinated among providers. Translating the concepts of the medical home and comprehensive health care for individuals with CAH offers many benefits for the affected individuals and their families. This manuscript represents the recommendations of a 1.5 day meeting held in September 2009 to discuss the ideal goals for comprehensive care centers for newborns, infants, children, adolescents, and adults with CAH. Participants included pediatric endocrinologists, internal medicine and reproductive endocrinologists, pediatric urologists, pediatric surgeons, psychologists, and pediatric endocrine nurse educators. One unique aspect of this meeting was the active participation of individuals personally affected by CAH as patients or parents of patients. Representatives of Health Research and Services Administration (HRSA), New York-Mid-Atlantic Consortium for Genetics and Newborn Screening Services (NYMAC), and National Newborn Screening and Genetics Resource Center (NNSGRC) also participated. Thus, this document should serve as a “roadmap” for the development phases of comprehensive care centers (CCC) for individuals and families affected by CAH

Aged PROP1 Deficient Dwarf Mice Maintain ACTH Production

Humans with PROP1 mutations have multiple pituitary hormone deficiencies (MPHD) that typically advance from growth insufficiency diagnosed in infancy to include more severe growth hormone (GH) deficiency and progressive reduction in other anterior pituitary hormones, eventually including adrenocorticotropic hormone (ACTH) deficiency and hypocortisolism. Congenital deficiencies of GH, prolactin, and thyroid stimulating hormone have been reported in the Prop1null (Prop1-/-) and the Ames dwarf (Prop1df/df) mouse models, but corticotroph and pituitary adrenal axis function have not been thoroughly investigated. Here we report that the C57BL6 background sensitizes mutants to a wasting phenotype that causes approximately one third to die precipitously between weaning and adulthood, while remaining homozygotes live with no signs of illness. The wasting phenotype is associated with severe hypoglycemia. Circulating ACTH and corticosterone levels are elevated in juvenile and aged Prop1 mutants, indicating activation of the pituitary-adrenal axis. Despite this, young adult Prop1 deficient mice are capable of responding to restraint stress with further elevation of ACTH and corticosterone. Low blood glucose, an expected side effect of GH deficiency, is likely responsible for the elevated corticosterone level. These studies suggest that the mouse model differs from the human patients who display progressive hormone loss and hypocortisolism