Molecular and clinical advances in congenital adrenal hyperplasia

Adult height of children with congenital adrenal hyperplasia due to 21-hydroxylase deficiency

BACKGROUND/PURPOSES

Congenital adrenal hyperplasia attributable to 21-hydroxylase deficiency (21-OHD) is a disorder of adrenal steroidogenesis. Achievement of optimal growth by such patients is challenging. We evaluated the adult height of Taiwanese children with 21-OHD and the effect of a gonadotropin-releasing hormone analogue (GnRHa) in patients with central precocious puberty (CPP) complicating 21-OHD.

METHODS

Among 116 patients with 21-OHD in Taiwan, 90 who had attained adult height were subjected to an analysis of height outcomes. Nine with progressive CPP were treated with GnRHa and the effects of this therapy on adult height were further analyzed.

RESULTS

In the pre-screening era, the percentage of boys with 21-OHD was lower than expected. Although neonatal screening can prevent mortality caused by adrenal crisis, some cases may be missed. The pooled mean adult height of the 78 patients treated with conventional therapy were -1.1 SD and -0.5 SD adjusting for the genetic potential. The disease features affecting height outcomes are the genetic height potential and in boys the simple virilizing type. Nine patients with CPP were treated with GnRHa in addition to conventional therapy; the mean adult height increased from the predicted -4.1 SD to -1.0 SD after 6.0 ± 2.5 years of treatment.

CONCLUSION

Patients with 21-OHD had poorer mean adult height. A high caregiver's index of suspicion is required for the early diagnosis of patients with 21-OHD missed on neonatal screening. Adjuvant therapy with GnRHa can improve the adult height of patients with CPP complicating 21-OHD.

Challenges in the Diagnosis of Simple-Virilizing Congenital Adrenal Hyperplasia: A Case Report

Simple-virilizing congenital adrenal hyperplasia (CAH) is a rare disorder. The objective of this case report is to highlight the challenges in early diagnosis and the treatment of ambiguous genitalia so that a patient can be treated at an early stage and irreversible changes can be prevented.

A 13-year-old child, assigned female at birth, presented with the chief complaints of primary amenorrhea. The patient also reported ambiguous genitalia, male pattern hair growth, and deepening of voice (which was progressive and first noted at six years of age). She was evaluated at six years of age but not by an expert.

Ultrasound showed a normal uterus and bilateral ovaries, karyotyping XX pattern. On hormonal analysis, serum testosterone and dehydroepiandrosterone sulfate were raised but 17-hydroxyprogesterone (17-OHP) was low; this was against the diagnosis of CAH. As 17-OHP was not raised, we performed a computerized tomography scan, which showed adrenal hyperplasia. A repeat 17-OHP test showed a level of 2,000 ng/dL (>800 ng/dL is diagnostic of CAH).

We highlight several challenges in the diagnosis of the simple virilizing form of CAH. The patient’s primary complaint was primary amenorrhea, she herself did not think virilization to be important. Possibly due to social and financial issues, she had not received expert opinion in early childhood. We cannot rely solely on an investigation alone but need to see the patient as a whole. With proper and timely referral and diagnosis, we can limit serious morbidity in the form of virilization as treatments to prevent it are basic.

Androgen-metabolizing enzymes: A structural perspective

Androgen-metabolizing enzymes convert cholesterol, a relatively inert molecule, into some of the most potent chemical messengers in vertebrates. This conversion involves thermodynamically challenging reactions catalyzed by P450 enzymes and redox reactions catalyzed by Aldo-Keto Reductases (AKRs). This review covers the structures of these enzymes with a focus on active site interactions and proposed mechanisms. Due to their role in a number of diseases, particularly in cancer, androgen-metabolizing enzymes have been targets of drug design. Hence we will also highlight how existing knowledge of structure is being used to this end.

Successful pregnancy and delivery of a patient with congenital adrenal hyperplasia

Congenital adrenal hyperplasia (CAH) during pregnancy is a rare condition. Only a few cases have been reported in the literature. CAH patients has lower pregnancy rate compared to normal women. A 27-year-old nulliparous woman, a diagnosed case of 21-hydroxylase deficient simple virilising form of classic CAH visited. She got pregnant spontaneously without any trial of assisted reproductive technology. At the age of 12, she underwent clitoral resection and vaginoplasty. She took dexamethasone or prednisolone after operation. She delivered healthy singleton female baby by cesarean section. Four years later, she delivered healthy singleton female baby by repeat cesarean section. Two female babies have shown normal external genitalia. Here, we report a case of successful pregnancy and delivery in a patient with CAH.

The Interplay between Estrogen and Fetal Adrenal Cortex

Estrogen is a steroid hormone that regulates embryogenesis, cell proliferation and differentiation, organogenesis, the timing of parturition, and fetal imprinting by carrying chemical messages from glands to cells within tissues or organs in the body. During development, placenta is the primary source of estrogen production but estrogen can only be produced if the fetus or the mother supplies dehydroepiandrosterone (DHEA), the estrogen prohormone. Studies show that the fetal zone of the fetal adrenal cortex supplies 60% of DHEA for placental estrogen production, and that placental estrogen in turn modulates the morphological and functional development of the fetal adrenal cortex. As such, in developed countries where humans are exposed daily to environmental estrogens, there is concern that the development of fetal adrenal cortex, and in turn, placental estrogen production may be disrupted. This paper discusses fetal adrenal gland development, how endogenous estrogen regulates the structure and function of the fetal adrenal cortex, and highlights the potential role that early life exposure to environmental estrogens may have on the development and endocrinology of the fetal adrenal cortex.

Defects of steroidogenesis

In the biosynthesis of steroid hormones the neutral lipid cholesterol, a normal constituent of lipid bilayers is transformed via a series of hydroxylation, oxidation, and reduction steps into a vast array of biologically active compounds: mineralocorticoids, glucocorticoids, and sex hormones. Glucocorticoids regulate many aspects of metabolism and immune function, whereas mineralocorticoids help maintain blood volume and control renal excretion of electrolytes. Sex hormones are essential for sex differentiation in male and support reproduction. They include androgens, estrogens, and progestins. A block in the pathway of steroid biosynthesis leads to the lack of hormones downstream and accumulation of the upstream compounds that can activate other members of the steroid receptor family. This review deals with the clinical consequences of these blocks.

Neonatal screening for congenital adrenal hyperplasia: experience and results in Argentina

AIM

To report the experience of the neonatal screening program for congenital adrenal hyperplasia (CAH) carried out in Buenos Aires, Argentina, from 1997 to 2006.

POPULATION AND METHODS

17-Hydroxyprogesterone (17OHP) was measured with an immunofluorometric assay in filter paper blood samples collected at neonatal maternity discharge. Filter paper blood levels <40 nmol/l were considered normal. 17OHP levels from 40-90 nmol/l triggered a new assessment to decide on a course of action. Confirmation of CAH was made with levels >90 nmol/l. This led to clinical follow up. For preterm (PT) infants, data were adjusted according to percentiles for gestational age and/or birth weight.

RESULTS

From 80,436 screened newborns (46.8% girls), 8848 (11%) were PT. 15 term (T) and 3 PT infants were recalled (0.022%). Nine were confirmed as having CAH (8 T and 1 PT) (female/male: 0.8; incidence 1:8937). Mean ages of screening and treatment were 5.7 and 13 days. Only 33% of affected children were clinically suspected of having CAH prior to screening. Four boys and two girls presented salt-wasting forms and severe adrenal insufficiency crises were prevented as a result of the screening.

CONCLUSIONS

Our findings confirm the benefits of CAH neonatal screening in our country with a high incidence of the classical form. Established criteria of screening and follow up allowed us to detect unrecognized affected males and females and to successfully prevent salt-wasting crises.

Increased aggression and activity level in 3- to 11-year-old girls with congenital adrenal hyperplasia (CAH)

Experimental research in a wide range of mammals has documented powerful influences of androgen during early development on brain systems and behaviors that show sex differences. Clinical research in humans suggests similar influences of early androgen concentrations on some behaviors, including childhood play behavior and adult sexual orientation. However, findings have been inconsistent for some other behaviors that show sex differences, including aggression and activity level in children. This inconsistency may reflect small sample sizes and assessment limitations. In the present study, we assessed aggression and activity level in 3- to 11-year-old children with CAH (38 girls, 29 boys) and in their unaffected siblings (25 girls, 21 boys) using a questionnaire that mothers completed to indicate current aggressive behavior and activity level in their children. Data supported the hypotheses that: (1) unaffected boys are more aggressive and active than unaffected girls; (2) girls with CAH are more aggressive and active than their unaffected sisters; and (3) boys with and without CAH are similar to one another in aggression and activity level. These data suggest that early androgens have a masculinizing effect on both aggressive behavior and activity level in girls.

Congenital adrenal hyperplasia: diagnostic advances

Congenital adrenal hyperplasia is a group of autosomal recessive disorders resulting from the deficiency of one of the five enzymes required for the synthesis of cortisol in the adrenal cortex. The most frequent is steroid 21-hydroxylase deficiency, accounting for more than 90% of cases. Much has been learned about the genetics of the various clinical forms of 21-hydroxylase deficiency, and correlations between the genotype and the phenotype have been studied extensively. Gene-specific diagnosis is now feasible and neonatal screening and prenatal treatment have been widely implemented. This discussion will be limited to the most common form of congenital adrenal hyperplasia, with focus on the diagnostic advances in this disease.

A Novel 13-bp Deletion in Exon 1 of CYP21 Gene Causing Severe Congenital Adrenal Hyperplasia

Congenital adrenal hyperplasia (CAH) is a common autosomal recessive disorder mainly caused by defects in the steroid 21-hydroxylase gene (CYP21). In most cases, this defect is the result of gene conversion events between the functional CYP21 gene and the adjacent inactive pseudogene (CYP21P). Previous screening for mutations of 21-hydroxylase gene in 51 unrelated Tunisian CAH patients revealed 4 novel mutations that have not been reported to occur in the CYP21P pseudogene. The present paper describes the fifth new small 13-bp deletion in exon 1 found after sequencing the CYP21 gene of a Tunisian patient suffering from the salt-wasting form of CAH. The patient is a girl born to consanguineous parents; she is homozygous for a novel deletion. The 13-bp deletion causes a stop codon at amino acid 47, which is likely to result in an enzyme with no activity. Both parents are heterozygous for the small deletion as confirmed by nested PCR method. This novel mutation has not been reported to occur in the CYP21P pseudogene, indicating a casual mutagenic event rather than a conversion one.

Newborn screening for congenital adrenal hyperplasia has reduced sensitivity in girls

OBJECTIVES

To characterize Wisconsin-born infants with 21-hydroxylase deficiency-congenital adrenal hyperplasia (21-OH-D-CAH) who were not identified by the newborn screening for 21-OH-D-CAH, and to examine male and female screening 17-hydroxyprogesterone (17-OHP) levels.

STUDY DESIGN

Information on infants with false-negative results was gathered. Results of the Wisconsin newborn screening for 21-OH-D-CAH from January 1, 2000, to June 30, 2003, were analyzed to detect possible differences between male (n=119,842) and female (n=114,951) infants.

RESULTS

Six of 7 female infants with false-negative results had genital masculinization, and 4 of 8 infants with false-negative results had laboratory evidence of salt-wasting. None died, had a salt-wasting crisis, or was assigned the wrong sex. A significant difference in the mean 17-OHP levels between male (17.5 ng/mL) and female (15.4 ng/mL) infants (P <.0001) was detected. The sensitivity of newborn screening for female infants was 60%, compared with 80% for male infants.

CONCLUSIONS

Male and female infants have significantly different mean 17-OHP levels on newborn screening, and female infants comprise most of the infants with false-negative results. Although health professionals should not assume that newborn screening for 21-OH-D-CAH is a means of identifying all affected infants, the primary goals of newborn screening for CAH (prevention of salt-wasting crises and sex misassignment) are fulfilled.

Use of nonradioactive labeling to detect large gene rearrangements in 21-hydroxylase deficiency

PURPOSE

To establish the Southern blotting technique using hybridization with a nonradioactive probe to detect large rearrangements of CYP21A2 in a Brazilian cohort with congenital adrenal hyperplasia due to 21-hydroxylase deficiency (CAH-21OH).

METHOD

We studied 42 patients, 2 of them related, comprising 80 non-related alleles. DNA samples were obtained from peripheral blood, digested by restriction enzyme Taq I, submitted to Southern blotting and hybridized with biotin-labeled probes.

RESULTS

This method was shown to be reliable with results similar to the radioactive-labeling method. We found CYP21A2 deletion (2.5%), large gene conversion (8.8%), CYP21AP deletion (3.8%), and CYP21A1P duplication (6.3%). These frequencies were similar to those found in our previous study in which a large number of cases were studied. Good hybridization patterns were achieved with a smaller amount of DNA (5 mug), and fragment signs were observed after 5 minutes to 1 hour of exposure.

CONCLUSIONS

We established a non-radioactive (biotin) Southern blot/hybridization methodology for CYP21A2 large rearrangements with good results. Despite being more arduous, this technique is faster, requires a smaller amount of DNA, and most importantly, avoids problems with the use of radioactivity.

Prenatal androgens and gender-typed behavior: a study of girls with mild and severe forms of congenital adrenal hyperplasia

Gender-typed behaviors and interests were investigated in 26 girls, aged 2-10 years, affected with congenital adrenal hyperplasia (CAH) and in 26 unaffected girls matched for age. Girls with CAH were more interested in masculine toys and less interested in feminine toys and were more likely to report having male playmates and to wish for masculine careers. Parents of girls with CAH rated their daughters' behaviors as more boylike than did parents of unaffected girls. A relation was found between disease severity and behavior indicating that more severely affected CAH girls were more interested in masculine toys and careers. No parental influence could be demonstrated on play behavior, nor did the comparison of parents' ratings of wished for behavior versus perceived behavior in their daughters indicate an effect of parental expectations. The results are interpreted as supporting a biological contribution to differences in play behavior between girls with and without CAH.

High reliability of neonatal screening for congenital adrenal hyperplasia in Switzerland

Newborn screening for congenital adrenal hyperplasia (CAH) is justified by the sometimes difficult clinical diagnosis and the risks associated with missed diagnosis, particularly the life-threatening salt-wasting crisis. In Switzerland, nationwide screening for CAH by measuring 17-hydroxyprogesterone levels in dried blood spots was introduced in 1992. At the Zurich University Children's Hospital, 50% of the population of Switzerland is screened. The aim of the study was to evaluate the efficiency of the Zurich screening program. Between January 1, 1993, and May 31, 2001, 333,221 newborns were screened for CAH. Thirty-one newborns had CAH (incidence, 1 in 10,749); 30 were detected through screening (sensitivity, 97%). A recall for suspected CAH was performed in only 60 cases, corresponding to a very low recall rate (0.0018%). In 30 recalls CAH was confirmed (positive predictive value, 50%; specificity, 99.99%). Fifteen of 31 patients profited from screening, as CAH had not been recognized clinically. The timely availability of screening results made therapy possible within the first week of life in most cases and helped in preventing salt-wasting crisis in all patients. With a sensitivity of 97%, a specificity of 99.99%, and a positive predictive value of 50%, the Zurich neonatal screening program for CAH can be considered highly reliable.

The diagnosis of congenital adrenal hyperplasia in the newborn by gas chromatography/mass spectrometry analysis of random urine specimens

Definitive neonatal diagnosis of congenital adrenal hyperplasia (CAH) is frequently complicated by normal 17-hydroxyprogesterone levels in 21-hydroxylase-deficient patients, residual maternal steroids, and other interfering substances in neonatal blood. In an effort to improve the diagnosis, we developed a gas chromatography/mass spectrometry method for simultaneous measurement of 15 urinary steroid metabolites as early as the first day of life. Furthermore, we developed 11 precursor/product ratios that diagnose and clearly differentiate the four enzymatic deficiencies that cause CAH. Random urine samples from 31 neonatal 21-hydroxylase-deficient patients and 59 age-matched normal newborns were used in the development. Additionally, samples from two 11 beta-hydroxylase-deficient patients and one patient each for 17 alpha-hydroxylase and 3 beta-hydroxysteroid dehydrogenase deficiencies were used. The throughput for one bench-top gas chromatography/mass spectrometry instrument is 20 samples per day. Thus, this method affords an accurate, rapid, noninvasive means for the differential diagnosis of CAH in the newborn period without the need for invasive testing and ACTH stimulation.

Rapid screening method to detect mutations in CYP21, the gene for 21-hydroxylase

To facilitate a rapid and practical molecular diagnosis of 21-hydroxylase deficiency (21-OHD), we developed a polymerase chain reaction (PCR) test in which only the 21-OH gene (CYP21) is amplified. We applied the test to diagnose 23 patients with salt-wasting type of 21-OHD. The upstream and downstream sequences of CYP21 have been specifically amplified by using a primer set containing the 8-bp deletion sequence of exon 3, which is distinct from its pseudogene CYP21P. The amplified PCR products were further subjected to mutation detection by restriction analysis: E1PL by AciI, I2g by PstI, E63a by DraIII, E7VL by ApaLI, E8non by PstI, and E8RW by AciI. To detect delections and/or gene conversions occurring on exon 3, we used the method described by Rumsby and Honour [1990: J Med Genet 27:676-678]. Our method is able to elucidate 8 common CYP21 mutations by using only 3 primer pairs and 4 restriction enzymes. The overall detection ratio of abnormal haplotypes by this method was over 95%, indicating that our method is practical and useful, particularly for carrier detection.

Leydig cell tumors and tumors associated with congenital adrenal hyperplasia

Testicular cancers occur at a rate of 2 cases per 100,000 males. Gonadal stromal tumors, including Leydig cell tumors and tumors of the adrenogenital syndrome, account for 1% to 3% of these neoplasms. Despite their rarity, these hormone-producing tumors are particularly interesting because of their potential for causing endocrinologic manifestations in prepubertal and adult males. They are also clinically significant, and early identification is critical to avoid profound and often irreversible developmental changes in affected children. An accurate diagnosis is important to differentiate tumors that will respond to medical management from tumors that require definitive surgical therapy.

Carrier analysis and prenatal diagnosis of congenital adrenal hyperplasia caused by 21-hydroxylase deficiency in Chinese

Congenital adrenal hyperplasia (CAH) is a common autosomal recessive disorder mainly caused by defects in the steroid 21-hydroxylase (CYP21) gene. We screened 1,000 healthy people, using a previously developed differential PCR method combined with single-strand conformation polymorphism and amplification-created restriction site methods for the carrier detection of the CYP21 gene deficiency. Our results indicated that the rate of occurrence of the heterozygous CAH carrier was about 12 in 1,000, with a gene frequency of 0.0060 and an incidence frequency of 1 in 28,000 in the Chinese population. In addition, 9 cases of CAH families were performed with prenatal diagnosis. Among them, 3 cases were diagnosed as the severe form, 4 cases carried the heterozygous mutation, and 2 were normal. This is the first report of carrier frequency analysis and prenatal diagnosis of 21-hydroxylase deficiency in Chinese.

Transcriptional regulatory elements of the human gene for cytochrome P450c21 (steroid 21-hydroxylase) lie within intron 35 of the linked C4B gene

The CYP21 gene, which encodes P450c21, the adrenal steroid 21-hydroxylase needed for glucocorticoid synthesis, lies in the major histocompatibility locus only 2.3 kilobase pairs (kb) downstream from the C4 gene. A 300-base pair (bp) proximal promoter and two upstream regions within C4 are needed for expression of mouse CYP21; the human gene also has a proximal promoter, but upstream elements have not been studied. To search for upstream regulatory elements in human CYP21B, we examined up to 9 kb of 5'-flanking DNA by transient transfection into human adrenal NCI-H295A cells. The 300-bp proximal promoter had substantial activity, but constructs retaining the DNA between -4.6 and -5.6 kb had increased activity, indicating the presence of distal elements. This region does not correspond to the mouse upstream regions, lying further upstream within intron 35 of C4B, which encompasses the previously described "Z promoter." DNase I footprinting located two elements, F1 and F2, lying -186 to -195 bp and -142 to -151 bp upstream from the Z cap site (-4862 to -4871 and -4818 to -4827 bp upstream of the CYP21B cap site). Each element formed a specific DNA-protein complex and conferred orientation-independent expression to a heterologous promoter. Mutations abolished formation of the DNA-protein complexes but only partially decreased expression. We identified a third site, F3, lying at -33 to -42 bp from Z. Competitive gel mobility supershift assays and co-transfection studies with SF-1 produced in vitro indicate F2 and F3 bind SF-1; BLAST searches and Southwestern blotting suggest that NF-W2 may bind F1. These results indicate that the Z promoter is a component of the CYP21 promoter needed to drive its adrenal-specific expression and that CYP21 transcription elements within C4 have kept these two genes linked during evolution.

No overrepresentation of congenital adrenal hyperplasia in patients with adrenocortical tumours

OBJECTIVE

The development and progression of sporadic adrenocortical tumours are poorly understood. In autopsy studies adrenocortical tumours are found in between 2 and 9% of the general population. In congenital adrenal hyperplasia (CAH), decreased production of cortisol leads to increased secretion of ACTH from the pituitary, resulting in hyperplasia of the adrenals. More than 95% of all cases of CAH are due to steroid 21-hydroxylase deficiency, resulting from mutations in the CYP21 gene. In subjects homozygous and heterozygous for CYP21 mutations, adrenocortical tumours have been found in a high frequency compared to the general population, suggesting that chronic ACTH stimulation may play a role in the development of this tumour form. In order to test whether mild undiagnosed CAH is a common predisposing factor, we screened 27 patients with sporadic adrenocortical tumours for CYP21 mutations.

DESIGN

A retrospective study.

PATIENTS

We screened 27 patients with sporadic adrenocortical tumours, representing both benign and malignant as well as hormonally active and silent lesions.

MEASUREMENTS

Mutation analyses of the CYP21 gene was performed by allele-specific PCR on high molecular weight DNA. The method used detects the nine CYP21 mutations that are responsible for 95% of all disease-causing alleles in CAH.

RESULTS

No mutations were detected in any of the 23 DNA samples that were prepared from leucocytes. In 4 cases where no leucocyte DNA was available, tumour tissue was analysed. In one of these tumours, two CYP21 mutations, V281 L and L307insT, were found in heterozygous form.

CONCLUSION

Our data indicate that mild undiagnosed congenital adrenal hyperplasia is not a common underlying factor predisposing to adrenocortical tumours, at least not in the Swedish population.

Molecular and clinical characterization of Korean patients with congenital lipoid adrenal hyperplasia

Congenital lipoid adrenal hyperplasia (CLAH) is a rare autosomal recessive disorder of steroid biosynthesis, caused by a molecular defect in the steroidogenic acute regulatory protein (StAR). Patients with CLAH usually manifest severe salt wasting, hypovolemia, enlargement of the adrenal glands and complete female external genitalia irrespective of the gonadal sex. CLAH seems to be more common in Koreans and Japanese than in other ethnic populations, with a preponderance of the mutation of a glutamine to a stop codon at the 258th amino acid residue (Q258X) in the StAR gene. Clinical findings of five unrelated Korean patients with CLAH and their molecular defects in the StAR gene are described, and the gene frequency of the Q258X mutation in the Korean population is investigated. All patients developed hypovolemic shock due to severe salt wasting in the first three months after birth. All were hyperpigmented, and three of five phenotypic females were genetic males. The basal ACTH level was extremely high in all patients with the minimal concentrations of all adrenal and gonadal steroids. The Q258X mutation was identified in 9 out of 10 alleles, indicating that the genetic defect in the StAR gene of Korean patients with CLAH is highly homogeneous probably due to a founder effect. The carrier frequency of the Q258X mutation in the normal Korean population has been estimated as approximately 1 in 250 with the allele frequency of 1 in 500. However, the confidence limits of the gene frequency for the mutant allele are wide (0.5 to 8.0 among 1,000 alleles). This implies that the carrier frequency could be lower, down to 1/1,000, or higher, up to 16/1,000.

Naturally occurring mutants of human steroid 21-hydroxylase (P450c21) pinpoint residues important for enzyme activity and stability

Three mutants (deletion of E196, G291S, and R483P) of steroid 21-hydroxylase (P450c21) from patients with inherited congenital adrenal hyperplasia had reduced activity toward progesterone and 17-hydroxyprogesterone after transient expression in cultured mammalian cells. In addition, both the E196 deletion and the R483P mutant had shorter half-lives than the wild-type enzyme, whereas the half-life of the G291S mutant was comparable with that of the normal protein. These results directly link the clinical situation with the three mutations and suggest that G291 is important for the catalytic activity of P450c21.

Congenital adrenal hyperplasia

Cogenital adrenal hyperplasia (CAH) is a family of genetic disorders from a deleterious mutation in a gene encoding adrenal steroidogenic enzyme essential for cortisol biosynthesis. Recent molecular advances have provided the genetic basis for the phenotypic variability in CAH, a means for accurately genotyping family members of CAH patients including prenatal prediction of the genotype in fetuses at risk of the disorder, and have helped to better define the hormonal criteria for the varying spectrum of CAH disorders. Biochemical advances have simultaneously aided the diagnosis and therapeutic monitoring of CAH patients. Prenatal maternal dexamethasone therapy for fetal CAH prevents or minimizes virilizing sequelae in the majority of prenatally treated affected females, but was associated with significant maternal side effects. Newborn screening for CAH has contributed to the prevention of morbidity of delayed diagnosis of CAH in more than two third of affected neonates. Current treatment methods, however, may not be optimal for achieving normal genetic height and appropriate weight in CAH patients, and more effective approaches to CAH therapy remain to be explored.

A novel splicing junction mutation in the gene for the steroidogenic acute regulatory protein causes congenital lipoid adrenal hyperplasia

Congenital lipoid adrenal hyperplasia (lipoid CAH) is a relatively common genetic disorder of adrenal and gonadal steroidogenesis and is the most severe form of CAH. As typical affected individuals cannot produce any steroid hormones or can only produce low levels of steroid hormones in the adrenals and gonads, including glucocorticoids, mineralcorticoids, and sex steroids, a genetic defect in the cholesterol side-chain cleavage enzyme, cytochrome P450scc (CYPXIA1), has been postulated to be the cause of their insufficient production to date. Recently, Lin and co-workers proved a link between mutations of the steroidogenic acute regulatory protein (StAR) gene and the lipoid CAH phenotype. Therefore, we investigated both the cytochrome P450scc and StAR genes in a Korean family with a fairly mild form of lipoid CAH to identify the mutation(s) causing this disease. The result was that no mutations could be found in the two genes, except for a thymine (T) insertion into intron 2 of the StAR gene, 3 bp from the splice donor site of exon 2. PCR-amplified StAR genes from a normal subject and the patient were cloned into an expression vector and then introduced into COS-7 cells. Northern blot and reverse transcriptase-PCR analyses indicated that the StAR messenger ribonucleic acid derived from the vector with the normal StAR gene spliced exons 2 and 3 correctly, whereas most, but not all, StAR messenger ribonucleic acid derived from the vector with the T-inserted StAR gene could not remove intron 2. We concluded from these results that the T insertion into the StAR gene accounts for the lipoid CAH phenotype in this patient.

Developmental and functional biology of the primate fetal adrenal cortex

The unique characteristics of the primate (particularly human) fetal adrenal were first realized in the early 1900s when its morphology was examined in detail and compared with that of other species. The unusual architecture of the human fetal adrenal cortex, with its unique and disproportionately enlarged fetal zone, its compact definitive zone, and its dramatic remodeling soon after birth captured the interest of developmental anatomists. Many detailed anatomical studies describing the morphology of the developing human fetal adrenal were reported between 1920 and 1960, and these morphological descriptions have not changed significantly. More recently, it has become clear that fetal adrenal cortical growth involves cellular hypertrophy, hyperplasia, apoptosis, and migration and is best described by the migration theory, i.e. cells proliferate in the periphery, migrate centripetally, differentiate during their migration to form the functional cortical zones, and then likely undergo apoptosis in the center of the cortex. Consistent with this model, cells of intermediate phenotype, arranged in columnar cords typical of migration, have been identified between the definitive and fetal zones. This cortical area has been referred to as the transitional zone and, based on the expression of steroidogenic enzymes, we consider it to be a functionally distinct cortical zone. Elegant experiments during the 1950s and 1960s demonstrated the central role of the primate fetal adrenal cortex in establishing the estrogenic milieu of pregnancy. Those findings were among the first indications of the function and physiological role of the human fetal adrenal cortex and led Diczfalusy and co-workers to propose the concept of the feto-placental unit, in which DHEA-S produced by the fetal adrenal cortex is used by the placenta for estrogen synthesis. Tissue and cell culture techniques, together with improved steroid assays, revealed that the fetal zone is the primary source of DHEA-S, and that its steroidogenic activity is regulated by ACTH. In recent years, function of the human and rhesus monkey fetal adrenal cortical zones has been reexamined by assessing the localization and ontogeny of steroidogenic enzyme expression. The primate fetal adrenal cortex is composed of three functionally distinct zones: 1) the fetal zone, which throughout gestation does not express 3 beta HSD but does express P450scc and P450c17 required for DHEA-S synthesis; 2) the transitional zone, which early in gestation is functionally identical to the fetal zone but late in gestation (after 25-30 weeks) expresses 3 beta HSD, P450scc, and P450c17, and therefore is the likely site of glucocorticoid synthesis, and 3) the definitive zone, which lacks P450c17 throughout gestation but late in gestation (after 22-24 weeks) expresses 3 beta HSD and P450scc, and therefore is the likely site of mineralocorticoid synthesis. Indirect evidence, based on effects of P450c21 deficiency and maternal estriol concentrations, indicate that the fetal adrenal cortex produces cortisol and DHEA-S early in gestation (6-12 weeks). However, controversy exists as to whether cortisol is produced de novo or derived from the metabolism of progesterone, as data regarding the expression of 3 beta HSD in the fetal adrenal cortex early in gestation are conflicting. During the 1960s, Liggins and colleagues demonstrated that in the sheep, cortisol secreted by the fetal adrenal cortex late in gestation regulates maturation of the fetus and initiates the cascade of events leading to parturition. Those pioneering discoveries provided insight into the mechanism underlying the timing of parturition and therefore were of particular interest to obstetricians and perinatologists confronted with the problems of preterm labor. However, although cortisol emanating from the fetal adrenal cortex promotes fetal maturation in primates as it does in sheep, its role in the regulation of primate parturition, unlike that in sheep

Congenital adrenal hyperplasia

A clinical spectrum, varying from prenatal onset to postnatal onset of symptoms, exists in all hyperandrogenic forms of congenital adrenal hyperplasia (CAH). Postnatal onset hyperandrogenic symptoms such as premature pubarche, clitoromegaly, hirsutism, menstrual disorders and infertility are well known manifestations of CAH due to 21-hydroxylase deficiency, 3 beta-hydroxysteroid dehydrogenase deficiency or 11 beta-hydroxylase deficiency. These hyperandrogenic symptoms of CAH are clinically indistinguishable from other causes of hyperandrogenism. The molecular data has proven the genetic basis for the phenotypic variability of CAH disorders. Specific hormonal criterion(a) defined by the molecular proof of the disorder should aid in discriminating between symptomatic patients due to CAH and other causes, and between those with mild and severe CAH disorders. Prevalence of the hyperandrogenic forms of CAH, as well as pubertal maturation and reproductive function in women with hyperandrogenic forms of CAH, are discussed.

Rapid screening method for detecting mutations in the 21-hydroxylase gene

Impaired synthesis of adrenal steroid hormones because of steroid 21-hydroxylase deficiency is one of the most common inborn errors of metabolism. To expedite molecular diagnosis in families with 21-hydroxylase deficiency, we have designed a rapid strategy to determine nine of the most common mutations in the 21-hydroxylase gene. According to the mutation to be detected, we apply either of two simple strategies: digestion with adequate restriction enzyme or use of the amplification-created restriction site (ACRS) approach and subsequent restriction analysis. Both procedures are rapid and, being nonradioactive, are safer to perform; moreover determination of zygosity in the analyzed mutations requires only one tube per mutation.

Pathophysiology, genetics, and treatment of hyperandrogenism

Presenting symptoms of hirsutism and virilism often signal a disorder of androgen biosynthesis, especially one of the forms of adrenal hyperplasia. The genetics and physiology of the various disorders are reviewed, emphasizing those that results in increased adrenal androgen production. All of these disorders can be diagnosed genetically, permitting family counseling, and all can be treated successfully with appropriate hormonal replacement therapy. Premature adrenarche is not caused by an enzymatic disorder; its origins remain obscure but may be an early harbinger of the polycystic ovary syndrome.

New developments in congenital lipoid adrenal hyperplasia and steroidogenic acute regulatory protein

To date, studies of patients with lipoid CAH have shown the indispensable role of StAR in the production of steroids by adrenal gland and gonads. Lipoid CAH is the first and so far only inborn disorder of steroid hormone synthesis and metabolism that is not caused by a defective steroidogenic enzyme but rather by a defect in cholesterol transport.

Improved precision of newborn screening for congenital adrenal hyperplasia using weight-adjusted criteria for 17-hydroxyprogesterone levels

OBJECTIVE

To evaluate the efficacy and efficiency of weight-adjusted threshold levels for 17-hydroxyprogesterone (17-OHP) in screening newborn infants for 21 hydroxylase deficiency-congenital adrenal hyperplasia (21-OH-D-CAH).

DESIGN

Analysis of the number of false-positive reports and diagnoses in infants, of 21-OH-D-CAH with the use of two strategies. Before October 1993, separate criteria for definite abnormal 17-OHP levels were established and implemented for 41,846 infants on the basis of birth weight: either less than 2200 gm (17-OHP level, 90 ng/ml) or 2200 gm or more (40 ng/ml). To reduce the burden of follow-up testing in low birth weight infants, criteria for definite abnormal 17-OHP results were statistically determined for four, rather than two, birth weight divisions: 1299 gm or less (17-OHP level > or = 165 ng/ml), 1300 to 1600 gm (> or = 135 ng/ml), 1700 to 2200 gm (> or = 90 ng/ml), and more than 2200 gm (> or = 40 ng/ml). These criteria were applied to the next 149,684 infants screened, and rates of false-positive test results and of false-positive diagnoses of 21-OH-D-CAH were compared.

RESULTS

Before implementation of four-tiered weight-adjusted 17-OHP criteria, 205 definite abnormal reports yielded four confirmed cases of 21-OH-D-CAH (positive predictive value = 2%; incidence of 21-OH-D-CAH = 1 in 10,461). With the revised criteria, 61 of 149,684 infants had definite abnormal results and 14 cases of 21-OH-D-CAH were confirmed (positive predictive value, 20%; incidence of 21-OH-D-CAH, 1 in 10,692). No undetected severe cases of 21-OH-D-CAH have been subsequently reported.

CONCLUSIONS

Weight-adjusted criteria for 17-OHP levels in screening for 21 -OH-D-CAH markedly reduced the number of false-positive results requiring immediate follow-up testing, particularly among low birth weight infants. Increased specificity afforded by these criteria was not accompanied by diminished sensitivity in detecting severe cases. Long-term follow-up of this screened cohort will determine whether the goals of newborn screening for 21-OH-D-CAH are adequately and efficiently fulfilled by this approach.

Mutations of the steroid 21-hydroxylase gene in an Argentinian population of 36 patients with classical congenital adrenal hyperplasia

In several studies carried out in USA and Europe, gene deletions, large gene conversions and six point mutations accounted for over 90% of the mutated alleles reported in classical congenital hyperplasia (CAH). In order to know the relative frequencies of mutations in a Latin-American population, the CYP21 active gene was analyzed in 42 patients with CAH belonging to 36 families attending two Argentinian clinics. The salt wasting form was diagnosed in 24 index cases and the simple virilized form in 12. When available, parents were also studied. DNA was extracted from peripheral blood leukocytes and specific PCR amplification of four different fragments of the CYP21 gene was carried out, followed by electrophoresis of the amplified product. The four fragments include segments of the gene containing the six most frequently reported abnormalities in classical CAH: IN2, EX3, R356W, cluster EX6 and I172N. Point mutations were studied by allelic specific oligonucleotide hybridization; Q318X was studied by digestion of the PCR product with PsT1 restriction enzyme and electrophoresis on 6% non-denaturing polyacrylamide gels. Deletions and macroconversions as well as confirmation of homozygote point mutations were studied by Southern blotting. Percentage distribution of abnormalities was as follows: deletion/macroconversion 18, IN2 18, I172N 15.3, Q318X 13.8, R356W 5.5, EX3 2.7, cluster EX6 0, not characterized 26.7. The complete genotype could be determined in 20 families while in 12 additional ones, the mutation was detected in one allele. Deletion/macroconversion, IN2, EX3 and Q318X were detected more frequently in salt wasting patients while I172N and R356W were found in simple virilized patients. However, genotype was not always concordant with phenotype. It is concluded that there are differences in the frequency of several gene mutations and in that of deletion/macroconversion between this Latin-American population and several reported American and European populations. In particular the percentage of deletion/macroconversion, IN2, EX3 and cluster EX6 was lower while I172N was higher in our Latin-American population. Furthermore the frequency of mutations not characterized was larger. This information is useful to delineate appropriate strategies for prenatal diagnosis in this particular population.

Congenital adrenal hyperplasia in Turkey: a review of 273 patients

In this study the clinical and epidemiological characteristics of congenital adrenal hyperplasia were evaluated retrospectively from the records of 273 patients managed in our clinic over a 25-year period. 21-Hydroxylase deficiency was present in 234 patients (85.7%), simple virilizing form in 134 (110 F, 24 M), salt-losing form in 85 (71 F, 14 M) and late on-set form in 15 girls. 11 beta-Hydroxylase deficiency was diagnosed relatively frequently (13.5%) among our patients with congenital adrenal hyperplasia; one girl had 17 alpha-hydroxylase deficiency and one boy had 3 beta-hydroxy steroid dehydrogenase deficiency. The median chronological age of diagnosis was 12 months (1 day-16.6 years) in patients with classical congenital adrenal hyperplasia. Chromosomal sex was 46, XX in a total of 221 patients and 46, XY in 52. Ninety-one girls were considered to be male before diagnosis was established and male sex was assigned in 31 of them due to development of male gender identity at diagnosis. Parental consanguinity rate among families of patients was higher than the general population in Turkey (56.4% vs 21%). Our overall figures show that the incidence of congenital adrenal hyperplasia is expected to be high due to a high rate of consanguinity in our populations and the patients remain frequently undiagnosed during the neonatal period. Therefore screening may be beneficial in our population.

Role of growth factors in the developmental regulation of the human fetal adrenal cortex

Development of the human fetal adrenals is characterized by rapid growth and high levels of steroidogenic activity during the latter two-thirds of pregnancy. By midgestation, the human fetal adrenals are composed of two distinct cortical zones: the predominant fetal zone, which occupies 80-90% of the cortical volume and produces large amounts of the delta 5-steroid dehydroepiandrosterone sulfate, and the narrow definitive zone, which surrounds the fetal zone. Late in gestation, the peripheral portion of the fetal zone develops into a third, functionally distinct compartment, the transitional zone, which is the likely site of cortisol synthesis. Soon after birth, the adrenal cortex is remodeled and the fetal zone disappears. The adult cortical zones are thought to arise from the definitive zone, which persists postnatally. Development of the human fetal adrenals is regulated primarily by corticortropin (ACTH) secreted from the fetal pituitary. However, as ACTH is not a mitogen per se, its proliferative actions on human fetal adrenal cortical cells are thought to be mediated by autocrine/paracrine growth factors produced by adrenal cortical cells in response to ACTH. In addition, these growth factors appear to modulate the functional response of fetal adrenal cortical cells to ACTH. The roles of several growth factors, including the insulin like growth factors I and II (IGF-I and IGF-II), epidermal growth factor (EGF), basic fibroblast growth factor (bFGF), activin, inhibin, and the transforming growth factors alpha and beta (TGF-alpha and TGF-beta) have been examined. In cultured human fetal adrenal cortical cells, EGF, bFGF, and IGF-I and -II are mitogenic, whereas activin and TGF-beta inhibit proliferation. IGF-II, activin, and TGF-beta also modulate ACTH-stimulated steroidogenesis. Human fetal adrenal cortical cells express IGF-II, bFGF and the activin/inhibin subunits, and the abundance of mRNAs for each of these factors is up-regulated by ACTH, suggesting that these growth factors are autocrine/paracrine mediators of ACTH action. Thus, although human adrenal development is primarily regulated by ACTH, its actions appear to be mediated/modulated by a cohort of locally expressed growth factors, the net effect of which results in the unique growth and steroidogenic activity of the human fetal adrenal cortex.

Function and membrane topology of wild-type and mutated cytochrome P-450c21

We have studied membrane topology of cytochrome P-450c21 (P450c21) using the approaches of mutagenesis and protease digestion. P450c21 is located at the cytoplasm with an N-terminal hydrophobic domain integrated into microsomal membranes. When this hydrophobic domain was replaced by a secretory signal peptide, P450c21 was translocated into the lumen and lost enzymic activity. No other topogenic sequence was detected in the bulk of the P450c21 peptide. A mutant protein with Pro-30 replaced by Leu (L30) corresponding to the mutation found in the diseased state was created. L30 protein lost 90% of enzymic activity, while a double mutant (L30R32) with an additional Leu-32 to Arg mutation had slightly higher residual enzymic activity. Apart from lower activity, L30 was also present in the cell at a lower level than wild-type P450c21. This lower level is probably due to increased degradation, as L30 is synthesized at a normal rate. Both L30 and L30R32 proteins, however, were integrated into membranes normally. Therefore the Pro-30 --> Leu mutation did not affect membrane integration, but affected the abundance and enzymic activity of P450c21.

Direct molecular diagnosis of CYP21 mutations in congenital adrenal hyperplasia

The majority of congenital adrenal hyperplasia (CAH) cases arise from mutations in the steroid 21-hydroxylase (CYP21) gene. Without reliance on HLA gene linkage analysis, we have developed primers for differential polymerase chain reaction (PCR) amplification of the CYP21 gene and the non-functional CYP21P gene. Using the amplification created restriction site (ACRS) approach for direct mutational detection, a secondary PCR was then performed using a panel of primers specific for each of the 11 known mutations associated with CAH. Subsequent restriction analysis allowed not only the detection but also the determination of the zygosity of the mutations analysed. Existing deletion of the CYP21 gene could also be detected. In the analysis of 20 independent chromosomes in 11 families of CAH patients in Taiwan, four CYP21 mutation types, besides deletion, were detected. Interestingly, in five different alleles, the CYP21P pseudogene contained some polymorphisms generally associated with the CYP21 gene. These results suggest gene conversion events that are occurring in both CYP21P and CYP21 genes. Our combined differential PCR-ACRS protocol is simple and direct and is applicable for prenatal diagnosis of CAH using chorionic villi or amniotic cells.

Role of the steroidogenic acute regulatory protein (StAR) in steroidogenesis

The rate-limiting, hormone-regulated, enzymatic step in steroidogenesis is the conversion of cholesterol to pregnenolone by the cholesterol side-chain cleavage enzyme system (CSCC), which is located on the matrix side of the inner mitochondrial membrane. However, it has long been observed that hydrophilic cholesterol-like substrates capable of traversing the mitochondrial membranes are cleaved to pregnenolone by the CSCC in the absence of any hormone stimulation. Therefore, the true regulated step in the acute response of steroidogenic cells to hormone stimulation is the delivery of cholesterol to the inner mitochondrial membrane and the CSCC. It has been known for greater than three decades that transfer of cholesterol requires de novo protein synthesis; however, prior to this time the regulatory protein(s) had yet to be identified conclusively. It is the purpose of this commentary to briefly review a number of the candidates that have been proposed as the acute regulatory protein. As such, we have summarized the available information that describes the roles of transcription, translation, and phosphorylation in this regulation, and have also reviewed the supporting cases that have been made for several of the proteins put forth as the acute regulator. We close with a comprehensive description of the Steroidogenic Acute Regulatory protein (StAR) that we and others have identified and characterized as a family of proteins that are synthesized and imported into the mitochondria in response to hormone stimulation, and for which strong evidence exists indicating that it is the long sought acute regulatory protein.

Sex reassignment: A challenging problem - current medical and islamic guidelines

Sexual ambiguity is a complex and often confusing medical problem. In addition to the life-threatening adrenal crises which may accompany some forms, ambiguity of the genitalia may lead to incorrect sex assignment by parents and/or health personnel. Children who present to medical attention beyond the neonatal period constitute a challenging problem due to the grave consequences of this condition. Thirty cases in whom sex reassignment was indicated were seen at King Khalid University Hospital, Riyadh, over a 10-year period. Of these, 27 (90%) were genetic females (20 were 21- and seven were 11-hydroxylase deficient) and three (10%) were genetic males (two partial androgen insensitive and one 5alpha-reductase deficient). All genetic males who were incorrectly assigned as females accepted reassignment. But 9 out of 27 (33%) of the genetic females who were incorrectly assigned as males refused reassignment. Preference for male sex assignment, delayed diagnosis and sociocultural circumstances seem to be the contributing factors for refusal. A national consensus about this important issue strengthened by the existing religious recommendations in demanded.

Does primary salt wasting occur in 11-beta-hydroxylase deficiency?

Renal salt wasting secondary to 11-beta-hydroxylase deficiency (11-beta-OHD) has been described in a few patients. This report describes an infant with 11-beta-OHD initially thought to be in adrenal crisis with renal salt wasting. Subsequently the sodium loss was found to be due to a secretory diarrhea, and this prompted us to critically review the literature of the previous case reports. In none has the entity of renal salt wasting secondary to 11-beta-OHD been unequivocally confirmed. The entity should remain in doubt until proven by appropriate studies in the future.

Congenital adrenal hyperplasia in a referral hospital in Saudi Arabia: Epidemiology, pattern and clinical presentation

Eighty-two children (30 males and 52 females) with congenital adrenal hyperplasia (CAH) were seen at King Khalid University Hospital (KKUH) over a 10-year period. Of these, 74 (90.2%) were Saudis and eight (9.8%) non-Saudis. Fifty-nine (72%) patients were 21-hydroxylase deficient. Of these, 56 (95%) had variable degrees of salt depletion. Nineteen (23.2%) patients had a deficiency of 11-ss-hydroxylase enzyme and four (4.8%) showed deficiency of 3-ss-hydroxysteroid dehydrogenase. The consanguinity rate was high (71.2%) and positive family history was documented in 45.8%. Thirty-nine infants deaths occurred within 25 families. The diagnosis was often delayed. Of the 52 females, 27 (52%) were initially assigned male sex. These results indicate the importance of physicians' awareness and the need for a neonatal screening program for early detection and appropriate management.

Radioimmunoassay of three deoxycorticoids in human plasma following HPLC separation

A radioimmunoassay of three deoxycorticoids, namely 11 beta,17 alpha-dihydroxy-4-pregnene-3,20-dione (21-deoxycortisol), 17 alpha,21-dihydroxy-4-pregnene-3,20-dione (11-deoxycortisol), and 21-hydroxy-4-pregnene-3,20-dione (11-deoxycorticosterone) which are important for differential diagnosis of congenital adrenal disorders, is described and evaluated. Antisera against 3-(O-carboxymethyl)oximes conjugated to bovine serum albumin were raised in rabbits. The radioligands were prepared by radioiodination of previously synthesized homologous tyrosine methyl ester derivatives. Following diethyl ether extraction, the steroids were separated from each other and from cross-reactants by HPLC using a Nucleosil C8 reverse-phase column and a methanol-water mixture (7:5, v/v) as an eluent. Normal levels of analyzed steroids ranged from 0.02 to 0.348, 0.185 to 3.80, and 0.013 to 0.299 nmol/l, for 21-deoxycortisol, 11-deoxycortisol and 11-deoxycorticosterone, respectively. The levels of both deoxycortisols rose significantly after ACTH treatment. Data are given with respect to the concentrations of these steroids in some pathological situations such as 21-hydroxylase and 11 beta-hydroxylase block, hyperaldosteronism, and polycystic ovary syndrome.