Initially elevated TSH and congenital central hypothyroidism due to a homozygous mutation of the TSH beta subunit gene: case report and review of the literature.

Congenital central hypothyroidism (CCH) is a rare disease which can be caused by mutations in the gene for the thyrotropin (TSH) beta subunit ( TSHB). The diagnosis is usually delayed because the TSH serum levels in these patients are not elevated leading to a negative result in the neonatal TSH screening. Herein, we report a 2-year-old girl with CCH due to a mutation in the TSHB gene, in whom the unusual finding of an initially elevated TSH level complicated the diagnostic workup. The proposita, who had a supposedly normal TSH screening result, is a German girl of non-consanguineous parents. At 5 weeks of age, her thyroid function tests showed peripheral hypothyroidism with a moderately increased TSH (23.8 microIU/ml) so that thyroid hormone substitution was initiated. At the age of 2 years, the administration of TRH failed to increase the TSH serum concentrations, which prompted TSH measurements with two different assay systems. Variable TSH levels ranging from not detectable low to elevated were found so that central hypothyroidism due to a mutation in the TSHB gene was suspected. This was confirmed by molecular analysis of the TSHB gene, which identified a homozygous deletion (delta 313 T) in the coding sequence. This mutation has been found in the German population before and may be a founder mutation. We conclude that depending on the assay system variable TSH serum levels in individuals with mutations in the TSHB gene may complicate the diagnostic workup.

Three novel point mutations of the CYP21 gene detected in classical forms of congenital adrenal hyperplasia due to 21-hydroxylase deficiency.

Congenital adrenal hyperplasia (CAH) [OMIM 201 910] is a group of autosomal recessive disorders most commonly due to 21-hydroxylase deficiency and presenting with a wide range of clinical manifestations. A limited number of inactivating pseudogene-derived mutations account for the majority of 21-hydroxylase gene ( CYP21) mutations, additional rare mutations can be found in single families and small populations. We found three novel CYP21 mutations in CAH patients suffering from the classical form of the disease, of which one is a frameshift mutation (1353-1354insA) leading to a premature termination codon (K277K, Q228A...E294X), one results in a premature stop codon (2551C>T, R444X), and one is a missense mutation (2609T>C; P463L). The frameshift and premature stop mutations can be predicted to result in a CYP21 protein without any residual enzyme activity. To determine the functional consequences of the P463L mutation, the IN VITRO enzyme activity was studied in COS-7 cells and revealed a reduced 21-hydroxylase activity of 2.6+/-0.8 (SD)% for the conversion of 17-hydroxyprogesterone (17OHP) to 11-deoxycortisol and of 3.0+/-0.5 % for the conversion of progesterone to 11-deoxycorticosterone (DOC). We conclude that functional analyses of unknown mutations provide information on the disease severity and should be always performed when novel CYP21 mutations are detected. Knowledge of the residual 21-hydroxylase function improves both genetic counselling and individual clinical management in CAH patients.

Absence of exercise-induced leptin suppression associated with insufficient epinephrine reserve in patients with classic congenital adrenal hyperplasia due to 21-hydroxylase deficiency.

OBJECTIVE: Patients with congenital adrenal hyperplasia (CAH) due to 21-hydroxylase deficiency suffer from glucocorticoid and mineralocorticoid deficiency. They have insufficient epinephrine reserves and increased basal leptin levels and are often insulin resistant. In healthy subjects, an inhibitory effect of acute catecholamine elevation on the leptin plasma concentrations has been reported. However, it is not yet known how leptin levels respond to exercise in CAH patients. METHODS: We performed a cycle ergometer test in six CAH patients to measure the response of plasma leptin, glucose and the catecholamines, epinephrine (E) and norepinephrine (N), as well as their respective metabolites, metanephrine (M) and normetanephrine (NM), to intense exercise. RESULTS: Baseline leptin concentrations in CAH patients were not different from those of controls. Leptin levels decreased significantly with exercise in healthy controls, whereas they remained unchanged in CAH patients. In contrast to controls, CAH patients showed no rise of plasma glucose. Basal and stimulated E and M levels were significantly lower in CAH patients compared to controls. Baseline and stimulated N and NM levels were comparable, showing a significant rise after exercise. Peak systolic blood pressure and peak heart rate in both groups were comparable. CONCLUSION: CAH patients do not manifest exercise-induced leptin suppression. The most probable reason for this is their severely impaired epinephrine stress response. In addition, epinephrine deficiency is leading to secondary changes in various catecholamine dependent metabolic pathways, e. g., energy balance. Although obvious clinical sequelae are so far unknown, the catecholamine-deficient state and the resulting hyperleptinemia might contribute to the severity of the disease in CAH.

LC-MS/MS based determination of basal- and ACTH-stimulated plasma concentrations of 11 steroid hormones: implications for detecting heterozygote CYP21A2 mutation carriers.

OBJECTIVE: Heterozygosity in 21-hydroxylase deficiency (21OHD) has been associated with hyperandrogenemic symptoms in children and adults. Moreover, the carrier status is mandatory for genetic counseling. We aimed at defining a hormonal parameter for carrier detection by mass spectrometry. DESIGN: Eleven basal and ACTH-stimulated steroid hormones of heterozygous carriers of CYP21A2 mutations and control individuals were compared. METHOD: Hormones were determined in plasma samples by liquid chromatography tandem mass spectrometry (LC-MS/MS) in 58 carriers (35 males, 23 females, age range 6-78 years) and 44 random controls (25 males, 19 females, age range 8-58 years). RESULTS: Heterozygotes could be identified best applying the 17-hydroxyprogesterone+21-deoxycortisol/cortisol×1000 ((17OHP+21S)/F×1000) equation 30  min after ACTH injection. An optimal cut-off value of 8.4 provided 89% sensitivity and specificity. Considering this data and a published frequency of heterozygotes of 1/50 to 1/61, the positive predictive value (PPV) of this cut-off is 12%. Of note, the negative predictive value (NPV) excluding heterozygosity in a given patient is 99.8%. CONCLUSION: Considering only marginal biochemical effects anticipated from heterozygosity, the stimulated ((17OHP+21S)/F×1000) identifies and excludes heterozygotes remarkably well. Nevertheless, LC-MS/MS cannot replace genetic testing, since sensitivity and specificity did not reach 100%. However, due to the considerably high NPV of the optimal cut-off and to a specificity of even 100% applying a cut-off higher than 14.7, hormonal assessment of heterozygosity can be of significant aid in conditions with limited access to genetic testing, as in some health care systems. The ((17OHP+21S)/F×1000) equation can guide diagnostic considerations in the differential diagnosis of hyperandrogenism.

Prenatal dexamethasone treatment in pregnancies at risk for congenital adrenal hyperplasia due to 21-hydroxylase deficiency: effect on midgestational amniotic fluid steroid levels.

Prenatal diagnosis of congenital adrenal hyperplasia (CAH) due to 21-hydroxylase deficiency by amniotic fluid (AF) steroid analysis is not possible in those cases in which prenatal dexamethasone (DEX) therapy is initiated to prevent virilization of female CAH fetuses because AF steroid levels are suppressed if DEX therapy is continued beyond amniocentesis (AC). In order to use AF steroids for prenatal diagnosis, it is necessary to discontinue DEX therapy for 5 days before AC. To study the effects of this interruption on AF steroid levels, we measured levels of aldosterone, corticosterone, 11-deoxycorticosterone, progesterone, 17-hydroxyprogesterone (170HP), 11-deoxycortisol, cortisol, and cortisone as well as androstenedione (delta 4-A) in AF samples (16-18 weeks) obtained from 25 pregnancies at risk for CAH treated with Dex (daily dosage: 1.0-1.5 mg). The prenatal diagnosis of 14 normal fetuses and 11 affected CAH fetuses was postnatally confirmed in all cases. Additionally, steroid levels were measured in AF samples (16-18 weeks) from 8 untreated CAH fetuses and in 19 AF samples (weeks 16-20) obtained in normal pregnancies. In 17/19 prenatally diagnosed CAH fetuses, the affected sibs had the salt wasting (SW)-form, in 2 cases the simple virilizing (SV)-form. All steroids were measured by RIA after extraction and Sephadex LH-20 chromatography. AF levels of aldosterone, corticosterone, deoxycorticosterone, progesterone, cortisol, cortisone, and 11-deoxycortisol were not different between CAH fetuses, prenatally DEX-treated normal fetuses and untreated controls. The 170HP-levels of the CAH-SW-fetuses (range: 19.9-59.8 mmol/L) were clearly above the normal range (3.74-11.6), but normal in the SV-fetuses (10.9, 11.5), whereas delta-4 A-levels (normal range: 0.87-5.13 mmol/L) were elevated both in the SW-(range: 6.53-37.6) and the SV-form (9.37,6.25) of CAH. 170HP and delta-4 A levels of prenatally DEX-treated pregnancies with normal fetuses were not different from levels found in normal pregnancies. Mean 170HP and delta-4 A AF steroid levels of prenatally DEX-treated CAH-pregnancies were slightly lower (NS) than levels of untreated CAH-pregnancies (170HP: 30.5 vs. 40.7; delta-4 A: 15.8 vs. 21.1). 170HP levels are elevated in the SW-form of CAH, but not in the SV-form. However, with the combination of 170HP and delta-4 A levels it is possible to diagnose prenatally both forms. There is no rebound phenomenon of AF steroid levels if DEX therapy is interrupted 5 days before amniocentesis.

Evidence for endocrinological abnormalities in heterozygotes for adrenal 11 beta-hydroxylase deficiency of a family with the R448H mutation in the CYP11B1 gene.

In about 5% of cases of classical congenital adrenal hyperplasia, steroid 11 beta-hydroxylase deficiency is the underlying defect. In two publications, no biochemical abnormalities have been reported in obligate heterozygotes for 11 beta-hydroxylase deficiency. We found the typical plasma steroid pattern of 11 beta-hydroxylase deficiency and identified the R448H mutation in the CYP11B1 gene in a boy presenting with pseudoprecocious puberty at age 2 yr. Both parents and an older sister were genotyped and were heterozygous carriers for the R448H mutation in CYP11B1. In contrast to the data reported in the literature, we found increased responses of plasma 11-deoxycortisol and 11-deoxycorticosterone in the short term ACTH test in the three family members heterozygous for the R448H mutation.

Multisteroid analysis in children with terminal aldosterone biosynthesis defects.

Aldosterone (Aldo), the most potent mineralocorticoid, is synthesized in the adrenal zona glomerulosa, requiring 11 beta-hydroxylation of 11-deoxycorticosterone (DOC) to form corticosterone (B), hydroxylation at position C18 to form 18-hydroxycorticosterone (18-OHB), and finally oxidation at position C18. There is a single cytochrome P450 enzyme (P450aldo) catalyzing all three reactions in the zona glomerulosa. The gene encoding for this enzyme is termed CYP11B2. There are two inborn errors of terminal aldosterone biosynthesis characterized by overproduction of B and deficient synthesis of Aldo. Corticosterone methyl oxidase deficiency type I (CMO-I) is characterized by decreased production of 18-OHB, whereas CMO-II is characterized by overproduction of 18-OHB and an elevated plasma ratio of 18-OHB to Aldo. Both disorders have an autosomal recessive inheritance and are rare causes of salt-wasting and failure to thrive in early infancy. In the last 10 yr, we diagnosed 16 infants with CMO deficiencies by simultaneous multisteroid analysis in a small plasma sample (RIA after extraction and automated high performance gel chromatography). All patients presented with severe failure to thrive in the first 3 months of life, associated with severe hyponatremia, hyperkalemia, and increased PRA. Basal Aldo levels were decreased (range, 0.055-0.11 nmol/L), whereas B was elevated (range, 19-154 nmol/L). Plasma 18-OHB, ranging from 0.063-0.44 nmol/L, was decreased or in the lower normal range in seven patients, whereas the other seven patients had elevated 18-OHB levels (range, 12.1-57.7 nmol/L). 18-OH-DOC (range, 0.81-7.8 nmol/L) and DOC (range, 0.7-9.53 nmol/L) levels were elevated in all patients. In seven patients, we found an elevated ratio of 18-OHB/Aldo (range, 286-900) and a low ratio of B/18-OHB (range, 1.1-5.8), whereas seven other patients had a low 18-OHB/Aldo ratio (range, 1.1-6.95) and a high B/18-OHB ratio (range, 41-1360). These findings confirmed the diagnosis of CMO-I in seven patients (low 18-OHB, 18-OHB/Aldo ratio < 10, and B/18-OHB ratio > 40) and the diagnosis of CMO-II in seven other patients (high 18-OHB, 18-OHB/Aldo ratio > 100, and B/18-OHB ratio < 10), whereas 18-OHB could not be determined in two patients. The B/18-OHB ratio appears particularly useful in CMO cases with undetectably low Aldo plasma levels and uncalculable 18-OHB/Aldo ratios. In conclusion, the simultaneous multisteroid determination method allows the precise differentiation of CMO-I and CMO-II in a small plasma sample during early infancy.

Hypogonadism in congenital adrenal hypoplasia: evidence for a hypothalamic origin.

Two unrelated boys with congenital adrenal hypoplasia were followed from birth for 20 yr. In spite of continuous treatment with hydrocortisone and fluorocortisone both patients had delayed growth and bone maturation since early childhood and failure of spontaneous puberty. Tests of the hypothalamic-pituitary function showed low basal plasma LH and FSH levels and blunted LH and FSH responses to standard GnRH tests and increased basal and TRH-stimulated PRL levels. Low dose pulsatile GnRH administration for 26 h, mimicking presumed physiological GnRH secretion, induced a continuing rise of plasma FSH in both patients and a slight increase of plasma LH and testosterone in one patient. These results indicate a hypothalamic origin of the gonadotropin deficiency with possible prenatal onset, since both patients had cryptorchidism during infancy. Hypogonadism in patients with adrenal hypoplasia may result from deficient steroid secretion of the hypoplastic fetal adrenals.

Long-term outcome after depot gonadotropin-releasing hormone agonist treatment of central precocious puberty: final height, body proportions, body composition, bone mineral density, and reproductive function.

A considerable number of patients with central precocious puberty (CPP) treated with depot GnRH agonists have reached final height (FH). The aim of this prospective, multicentric study was the evaluation of the benefits, side-effects, and long term outcome of depot GnRH agonist therapy. We investigated 50 young women (mean +/- SD age, 16.7+/-2.6 yr; range, 12.9-23.4 yr) at FH. They received depot triptorelin over a period of 4.4+/-2.1 yr (range, 1.0-9.7 yr). Target height (TH) and predicted adult height (PAH) at the start of treatment were 163.6+/-6.2 and 154.9+/-9.6 cm, respectively (P < 0.05). FH was 160.6+/-8.0 cm (FH vs. TH, P = NS; FH vs. PAH, P < 0.05). Young patients showed the highest height gain (FH minus initial PAH). Seventy-eight percent of all patients reached a FH within their TH range. Even in young patients and those with an unfavorable initial PAH below the TH range, 60% reached a FH within their individual TH range. Standardized bone mineral density and standardized bone mineral density SD score investigated by dual energy x-ray absorptiometry of the lumbar spine (L1-L4) were 1040.9+/-124.2 mg/cm2 and 0.0+/-1.0; those of the femoral neck were 902.2+/-115.4 mg/cm2 and 0.2+/-1.0, respectively. The SD score of the ratio of sitting height over lower leg length was normal (0.3+/-1.2). Body mass index SD scores at pretreatment, at the end of treatment, and at FH were not significantly different (2.0+/-2.0, 2.0+/-2.0, and 1.7+/-2.2, respectively). Menarche or remenarche started at age 12.3+/-1.4 yr (range, 9.3-15.8 yr) in all patients. In conclusion, long term depot GnRH agonist treatment of CPP girls preserved genetic height potential and improved FH significantly combined with normal body proportions. No negative effect on bone mineral density and reproductive function was seen. Treatment neither caused nor aggravated obesity.

Differentiation of male hypogonadotropic hypogonadism and constitutional delay of puberty by pulsatile administration of gonadotropin-releasing hormone.

It is not possible to differentiate reliably between male idiopathic hypothalamic hypogonadism (HH) and severe constitutional delay of puberty (CD) on the basis of a standard GnRH bolus test (GBT) or other known endocrine or clinical parameters. Therefore, we studied the response of 17 hypogonadal men, 8 with a diagnosis of HH (age, 15.5-41; bone age, 12.5-19 yr; testes, 1-4 ml) and 9 with CD (age, 14.5-20; bone age, 11-15 yr, testes, 2-10 ml) to pulsatile GnRH stimulation. Basal and peak LH and FSH levels after a single dose of GnRH greatly overlapped between the two groups. In each patient, a spontaneous nocturnal plasma profile of LH and FSH, sampled every 20 min, was followed by a pulsatile GnRH stimulation (5 micrograms iv every 90 min) via a portable minipump for 36 h. Before and after this pulsatile GnRH stimulation, a GBT (60 micrograms/m2 iv) was performed and plasma LH, FSH, testosterone, androstenedione, and dehydroepiandrosterone sulfate were measured. Pulse analysis revealed 0-5 spontaneous nocturnal LH peaks in the CD patients but only one in all of the HH patients. During the 36 h of pulsatile GnRH, mean LH and FSH levels were significantly higher (P less than 0.0001) than during the spontaneous nocturnal profile in all patients (except 1 from each group for LH). The GBT after pulsatile stimulation caused significantly higher (P less than 0.001) LH increments in CD than in HH patients, with no overlap between the two groups (range, 4.1-15.6 in CD vs. 0.8-2.4 mIU/ml in HH). Plasma testosterone rose significantly (P less than 0.01) during pulsatile GnRH from 67 to 155 ng/dl (median) in the CD men, but did not change in the HH group (21 to 22.5 ng/dl). Plasma androstenedione and dehydroepiandrosterone sulfate did not rise in either group. We conclude that, in contrast to other parameters investigated so far, the LH increment in the second GBT after 36 h of pulsatile GnRH allows clear-cut differentiation between CD and HH. These results indicate significantly lower pituitary LH reserve in patients with permanent HH after short term priming of the pituitary by pulsatile GnRH administration.

Congenital adrenal hypoplasia: clinical spectrum, experience with hormonal diagnosis, and report on new point mutations of the DAX-1 gene.

X-linked congenital adrenal hypoplasia (AHC) is a rare developmental disorder of the human adrenal cortex and is caused by deletion or mutation of the DAX-1 gene, a recently discovered member of the nuclear hormone receptor superfamily. Hypogonadotropic hypogonadism is frequently associated with AHC. AHC occurs as part of a contiguous gene syndrome together with glycerol kinase deficiency (GKD) and Duchenne's muscular dystrophy. The present series, collected over the past 2 decades, includes 18 AHC boys from 16 families: 4 with AHC, GKD, and Duchenne's muscular dystrophy; 2 with AHC and GKD; and 12 with AHC (5 young adults with hypogonadotropic hypogonadism). Most of the boys presented with salt wasting and hyperpigmentation during the neonatal period. Plasma steroid determinations performed in the first weeks of life often showed confusing results, probably caused by steroids produced in the neonates' persisting fetocortex. Aldosterone deficiency usually preceded cortisol deficiency, which explains why the patients more often presented with salt-wasting rather than with hypoglycemic symptoms. An ACTH test was often necessary to detect cortisol deficiency in the very young infants. In some patients, serial testing was necessary to establish the correct diagnosis. In 4 boys studied during the first 3 months after birth, we found pubertal LH, FSH, and testosterone plasma levels indicating postnatal transient activation of the hypothalamic-pituitary-gonadal axis as in normal boys. Previous studies have shown that the DAX-1 gene is deleted in the AHC patients with a contiguous gene syndrome and is mutated in nondeletion patients. Most of the point mutations identified in AHC patients were frameshift mutations and stop mutations. In the 15 patients available for molecular analysis of the DAX-1 gene, there were large deletions in 6 patients and point mutations in another 7 patients. All of the point mutations identified in the present study resulted in a nonfunctional truncated DAX-1 protein. Two brothers with primary adrenal insufficiency and a medical history that strongly suggested AHC had no mutation in the DAX-1 gene. Thus, additional, as yet unknown genes must play a part in normal adrenal cortical development.

Amino acid substitution R384P in aldosterone synthase causes corticosterone methyloxidase type I deficiency.

Corticosterone methyloxidase type I (CMO-I) deficiency is an autosomal recessively inherited disorder causing congenital hypoaldosteronism due to defects in aldosterone synthase (P450aldo), the enzyme that converts 11-deoxycorticosterone to corticosterone, 18-hydroxycorticosterone, and aldosterone. To clarify the molecular basis of CMO-I deficiency and gain further insight into the structure-function relationship of P450aldo, we cloned and sequenced the CYP11B2 gene (encoding P450aldo) of a male Caucasian patient suffering from CMO-I deficiency and identified a single point mutation leading to substitution of the highly conserved arginine-384 by proline (R384P). Differential hybridization of mutation-specific oligonucleotide probes to polymerase chain reaction-amplified CYP11B2 fragments revealed that both parents were heterozygous carriers for R384P, whereas the patient appeared homozygous. The patient's healthy brother and 85 individuals without known aldosterone synthase deficiency did not carry the R384P mutation. Introduction of this mutation into a CYP11B2 complementary DNA expression vector construct and subsequent expression in COS cells revealed that R384P leads to complete loss of 11 beta- and 18-hydroxylase activities of P450aldo. Thus, the R384P mutation provides a molecular explanation for the CMO-I deficiency in this patient and suggests that arginine-384 plays a major role in P450aldo function.

The steroid hormonal milieu of the undisturbed human fetus and mother at 16-20 weeks gestation.

The interrelations of steroid hormone levels in plasma and amniotic fluid from mothers and their undisturbed fetuses at early midgestation of human pregnancy have not been defined previously. We, therefore, studied 12 healthy mothers and their fetuses undergoing termination of pregnancy for social reasons at 16-20 weeks gestation. Fetal arterial and venous blood was obtained by direct vessel puncture through a fetoscope in the conscious sedated mothers immediately before termination of pregnancy. Simultaneously, maternal peripheral venous blood and amniotic fluid were collected. Aldosterone (Aldo), corticosterone (B), 11-deoxycorticosterone, progesterone (P), 17-hydroxyprogesterone (17OHP), 11-deoxycortisol, cortisol (F), and cortisone were simultaneously determined by specific RIA after extraction and chromatography. Positive fetal arterio-venous differences were found for F, B, and Aldo, whereas arteriovenous differences were negative for P and 17OHP. In amniotic fluid, six of the eight corticosteroids showed significantly lower levels during fetoscopy than during routine amniocentesis, as reported previously using the same analytical methods. The present study demonstrates that the undisturbed human fetus at 16-20 weeks gestation actively secretes the most important gluco- and mineralocorticoids, F, B, and Aldo, independent of the mother. P and 17OHP were shown to be primarily derived from placental production and supplied to the fetus as a source of F and Aldo biosynthesis. The fetoscopy procedure with premedication seemed to give rise to less stress to the fetus than routine amniocentesis without sedation. Fetoscopy is, therefore, an ideal method to study feto-maternal steroid interrelations in human pregnancy.

Plasma aldosterone and 11-deoxycortisol in term neonates: a reevaluation.

We reported previously reference values for seven corticosteroids in the plasma of term neonates and their mothers, including values for aldosterone (Aldo) that appeared high compared to the values in the literature. Plasma 11-deoxycortisol (S) was not measured in that longitudinal study. Using an improved technique of chromatographic separation of Aldo and S, the Aldo levels were measured again, and S levels were newly determined in stored plasma samples of the 12 newborn infants of our original report. The mean concentrations were: (Formula: see text). These plasma Aldo values should replace those of our original report. Thus, both plasma Aldo and S levels decline in the first week of life in normal infants.

Relevance of major histocompatibility complex class II expression as a hallmark for the cellular differentiation in the human adrenal cortex.

Major histocompatibility complex (MHC) class II antigens are expressed on adrenocortical cells of the zona reticularis and have been shown to be a marker of dignity. This suggests a correlation to the zellular differentiation of the adrenal cortex. Therefore, we immunohistochemically investigated the MHC class II expression in the context of the ontogenesis of the zonal and cellular differentiation in fetal, postnatal, childhood, and adult adrenals. Cell types and cell turnover were studied using specific immune markers (including expression of CD95/ Fas), in situ end labeling of apoptosis, and electron microscopy. We show that prenatal (fetal and definitive) steroid cells, as well as postnatal adrenals, reveal no expression of MHC class II. In childhood, these antigens first appear by the fourth year, in parallel with the differentiation of reticularis cells. The expression index in childhood was 7.43% +/- 2.78 (mean +/- SEM), in adult adrenals 18.63% +/- 3.14 (third decade), and 15.15% +/- 1.26 (fourth through sixth decade). In conclusion, MHC class II expression and the development of the functional maturation of the adult adrenal cortex occur simultaneously. The expression of MHC class II on steroid cells may thus be involved in potential immune-adrenal interactions.

Hereditary defect in biosynthesis of aldosterone: aldosterone synthase deficiency 1964-1997.

We studied two of the three patients with a hereditary defect in the biosynthesis of aldosterone originally described by Visser and Cost in 1964. All three presented as newborns with salt-losing syndrome and failure to thrive. The original biochemical studies showed a defect in the 18-hydroxylation of corticosterone. According to the nomenclature proposed by Ulick, this defect would be termed corticosterone methyl oxidase deficiency type I. We measured plasma steroids in the untreated adult patients and performed molecular genetic studies. Aldosterone and 18-OH-corticosterone were decreased, whereas corticosterone and 11-deoxycorticosterone were elevated, thus confirming the diagnosis of corticosterone methyl oxidase deficiency type I. Cortisol and its precursors were in the normal range. Genetic defects in the gene CYP11B2 encoding aldosterone synthase (P450c11Aldo) have been described in a few cases. We identified a homozygous single base exchange (G to T) in codon 255 (GAG) causing a premature stop codon E255X (TAG). This mutation destroys a Aoc II restriction site. Digestion of a PCR fragment containing exon 4 of CYP11B2 (261 bp) with this restriction enzyme revealed in the two patients homozygous for the E255X mutation only a 261-bp fragment, whereas the heterozygous parents had three fragments (261 bp from the mutant allele and 194 and 67 bp from the wild-type allele). The mutant enzyme had lost the five terminal exons containing the heme binding site, and thus there was a loss of function enzyme. We conclude that the biochemical phenotype of these prismatic cases of congenital hypoaldosteronism can be explained by the patients genotype.

Longitudinal studies of plasma aldosterone, corticosterone, deoxycorticosterone, progesterone, 17-hydroxyprogesterone, cortisol, and cortisone determined simultaneously in mother and child at birth and during the early neonatal period. I. Spontaneous delivery.

In order to obtain the still lacking reference data of individual plasma steroids in the immediate postnatal period needed for the assessment of adrenocortical function in various neonatal maladaptation syndromes, aldosterone (A), corticosterone, deoxycorticosterone (DOC), progesterone (P), 17-hydroxyprogesterone (17-OHP), cortisol, and cortisone were simultaneously followed in the same human newborn in a single 250-500 microliters peripheral plasma sample obtained at constant times during the first week of life using a mechanized Sephadex LH-20 multicolumn chromatography and standardized RIAs. Mean concentrations in 12 spontaneously delivered full term newborns of either sex and in paired umbilical (UV) and peripheral maternal (MV) venous plasma are given in the table. Besides significant maternoumbilical gradients in each steroid, DOC, P, 17-OHP, and cortisone, originating predominantly from the fetoplacental unit, disappear rapidly with steadily increasing half-lives. A, corticosterone, and cortisol, however, remain elevated in comparison with later infancy, with the exception of a marked "glucocorticoid dip" in cortisol and corticosterone levels between 2 and 12 h after birth.

Concentrations of aldosterone, corticosterone, 11-deoxycorticosterone, progesterone, 17-hydroxyprogesterone, 11-deoxycortisol, cortisol, and cortisone determined simultaneously in human amniotic fluid throughout gestation.

Corticosteroids (CS) are essential for fetal organ maturation; yet, knowledge of endogeneous CS and precursor levels throughout fetal life is limited. Therefore, unconjugated aldosterone (Aldo), corticosterone (B), 11-deoxycorticosterone (DOC), progesterone (P), 17 alpha-hydroxyprogesterone (17-OHP), 11-deoxycortisol (S), cortisol (F), and cortisone (E) were simultaneously determined by RIA after automated Sephadex LH-20 chromatography in 70 control samples of amniotic fluid (AF) obtained at all gestational ages between 14-42 weeks. Levels of the progestins P and 17-OHP slowly increased from means (+/- SE) of 14.7 +/- 2.8 and 1.63 +/- 0.21 ng/ml, respectively, in early gestation to maximum levels of 32.4 +/- 3.5 and 3.80 +/- 0.74 ng/ml at 36-38 weeks (P less than 0.005), then dropped significantly (P less than 0.01) to 19.2 +/- 2.2 and 1.58 +/- 0.22 ng/ml at term. All CS levels except E rose very markedly by 3- to 12-fold (P less than 0.0001) from the weeks 14-16 (DOC, 0.44 +/- 0.08; B, 1.49 +/- 0.23; Aldo, 0.043 +/- 0.012; S, 0.51 +/- 0.10; F, 5.96 +/- 0.93 ng/ml) until the 36-38th weeks (DOC, 3.50 +/- 0.66; B, 4.60 +/- 0.78; Aldo, 0.530 +/- 0.109; S, 6.00 +/- 0.75; F, 60.8 +/- 8.9 ng/ml). Term levels were significantly reduced (P less than 0.01) in the less active CS DOC (0.51 +/- 0.07 ng/ml), B (2.35 +/- 0.35 ng/ml), and S (1.14 +/- 0.14 ng/ml), whereas those of the biologically most potent CS Aldo and F declined less markedly (0.272 +/- 0.053 and 23.0 +/- 0.75 ng/ml, respectively, at 39-42 weeks). Levels of the inactive glucocorticoid E rose from 8.83 +/- 1.08 ng/ml at 14-16 weeks to 16.8 +/- 2.6 ng/ml at 31-35 weeks (P less than 0.01), then remained rather constant around 11.5 ng/ml until term. It is concluded that after the 25th week, large amounts of biologically active CS are available in AF which probably directly induce the final epithelial maturation of fetal lungs and intestinal tract.

Evidence for genetic heterogeneity of pseudohypoaldosteronism type 1: identification of a novel mutation in the human mineralocorticoid receptor in one sporadic case and no mutations in two autosomal dominant kindreds.

Pseudohypoaldosteronism type 1 (PHA1) is characterized by neonatal salt wasting resistant to mineralocorticoids. There are 2 forms of PHA1: the autosomal recessive form with symptoms persisting into adulthood, caused by mutations in the amiloride-sensitive luminal sodium channel, and the autosomal dominant or sporadic form, which shows milder symptoms that remit with age. Mutations in the gene encoding the human mineralocorticoid receptor (hMR) are, at least in some patients, responsible for the latter form of PHA1. We here report the results of a genetic study in a sporadic case and in 5 affected patients from 2 families with autosomal dominant PHA1. In the sporadic case we identified a new frameshift mutation, Ins2871C, in exon 9 of the hMR gene. Family members were asymptomatic and had no mutation. This mutation is the first described in exon 9 and impairs the last 27 amino acids of the hormone-binding domain. In 2 kindreds with autosomal dominant PHA1 we found no mutation of the hMR gene. Our results confirm the hypothesis that autosomal dominant or sporadic PHA1 is a genetically heterogeneous disease involving other, as yet unidentified, genes.

Longitudinal imaging reveals pituitary enlargement preceding hypoplasia in two brothers with combined pituitary hormone deficiency attributable to PROP1 mutation.

Mutations of the PROP-1 gene cause combined pituitary hormone deficiency. Progressive ACTH/cortisol insufficiency is found in a few patients. Congenital hypoplasia of the anterior pituitary gland is the most common magnetic resonance imaging finding in patients with PROP-1 mutations. We present two brothers with compound heterozygosity for the two mutations 150delA and 301-302delAG of the PROP-1 gene. Both showed combined pituitary hormone deficiency of GH, TSH, PRL, and gonadotropins, as is typical for PROP-1 deficiency. We observed a developing insufficiency of ACTH and cortisol secretory capacity in both patients. Computed tomography revealed an enlarged pituitary in the older brother at 3.5 yr of age. Repeated magnetic resonance imaging after 12 yr showed a constant hypoplasia of the anterior pituitary lobe. Similarly, magnetic resonance imaging of the younger brother showed a constant enlargement of the anterior pituitary gland until 10 yr. At the age of 11 yr, the anterior pituitary was hypoplastic. The reason for pituitary enlargement in early childhood with subsequent decrease in pituitary size is not known. We speculate that altered expression of early transcription factors could be involved. Because both patients have the same PROP-1 mutations and an identical pattern of combined pituitary hormone deficiency, we suggest that early pituitary enlargement may be the typical course in such patients in whom pituitary surgery is not indicated.