Steroid 21-hydroxylase deficiency: three additional mutated alleles and establishment of phenotype-genotype relationships of common mutations

Congenital adrenal hyperplasia with homozygous and heterozygous mutations: a rare family case report

BACKGROUND

Congenital adrenal hyperplasia (CAH), characterized by defective adrenal steroidogenesis, is transmitted in an autosomal recessive manner. Mutations in the steroid 21-hydroxylase gene CYP21A2 causing steroid 21-hydroxylase deficiency account for most cases of CAH. The c.145l-1452delGGinsC gene mutation is rare, and only one case has been reported, but the form of gene mutation is different from this case, resulting in different clinical phenotype. The most common pathogenic genotype of CAH is a homozygous or compound heterozygous mutation, but CAH patients homozygous for the p.I173N mutation and heterozygous for the c.1451-1452delGGinsC mutation have not been reported previously. We report herein a familial case of CAH, in which both siblings carry the rare homozygous p.I173N mutation and heterozygous c.1451-1452delGGinsC mutation.

CASE PRESENTATION

The proband showed amenorrhea, infertility, polycystic ovaries, and increased levels of androgen, rather than the typical clinical manifestations of CAH such as an adrenal crisis or masculine vulva, so was misdiagnosed with polycystic ovary syndrome for many years. Following a correct diagnosis of CAH, she was given glucocorticoid treatment, her menstruation became more regular, and she became pregnant and delivered a healthy baby girl.

CONCLUSIONS

The genotypes may be p.I173N homozygous or p.I173N/c.1451-1452delGGinsC heterozygous, both mutations could be pathogenic. This complex combination of mutations has not been reported or studied before. Through the report and analysis of this genotype, the content of CAH gene bank is enriched and the misdiagnosis rate of CAH is reduced.

Current and Novel Treatment Strategies in Children with Congenital Adrenal Hyperplasia

BACKGROUND

The standard treatment for congenital adrenal hyperplasia (CAH) in children is still hydrocortisone. Improved strategies for timing of the dose during the day and the dose per square meter body surface area used in children of different ages and developmental phases have improved the situation and outcome for the patients. Neonatal screening enables an earlier diagnosis and initiation of treatment, prevents from adrenal crisis, and improves growth and development also for children with the less severe forms of CAH.

SUMMARY

This review describes the current treatment strategies for children with CAH and discusses some potential treatment options that have been developed with the primary aim to decrease the adrenal androgen production. Novel modified release glucocorticoid therapies are also discussed.

KEY MESSAGES

The long-term effects of the new adjunct therapies are unknown, and some are not suitable for use in children and adolescents. The effects of the new therapies on bone mineral density, gonadal functions, and long-term cognitive development are yet to be assessed. It is not known what levels of adrenal androgens are optimal for normal growth, puberty, and bone health. The basis of using glucocorticoids and mineralocorticoids in the treatment of CAH remains, and in some individuals, it may be beneficial to add therapies to reduce the androgen load during certain life stages.

Non-Classical 21-Hydroxylase Deficiency: Analysis of a Mutant Gene in a Uyghur Family and Literature Review

OBJECTIVE

The gene mutation and clinical characteristics of a patient with non-classical 21-hydroxylase deficiency and his family were analyzed.

METHODS

A patient was diagnosed with non-classical 21-hydroxylase deficiency in the Department of Endocrinology of People's Hospital of Xinjiang Uygur Autonomous Region in December 2016. The clinical data and related gene-sequencing results were analyzed. The detected mutations were verified in nine members of the family.

RESULTS

Gene-sequencing results revealed that the proband and the other three members of the family (proband, proband's mother's younger brother and the proband's mother's younger brother's younger daughter, and proband's second elder sister) shared the following mutations: Ile173Asn, Ile237Asn, Val238Glu, Met240Lys, Val282Leu, Leu308Phefs*6, Gln319Ter, Arg357Trp, and Arg484Profs. The Val282Leu mutation was heterozygous in the proband's mother's younger brother's younger daughter, but homozygous in the other three individuals. The father of the proband, the elder brother of the father of the proband, the third younger brother of the father of the proband, and the elder sister of the proband all carried only the Val282Leu mutation.

CONCLUSION

Val282Leu is the gene responsible for non-classical 21-hydroxylase deficiency. Screening for this gene in the offspring of patients with non-classical 21-hydroxylase deficiency may help to identify cases early.

EMQN best practice guidelines for molecular genetic testing and reporting of 21-hydroxylase deficiency

Molecular genetic testing for congenital adrenal hyperplasia (CAH) due to 21-hydroxylase deficiency (21-OHD) is offered worldwide and is of importance for differential diagnosis, carrier detection and adequate genetic counseling, particularly for family planning. In 2008 the European Molecular Genetics Quality Network (EMQN) for the first time offered a European-wide external quality assessment scheme for CAH (due to 21-OH deficiency). The interest was great and over the last years at about 60 laboratories from Europe, USA and Australia regularly participated in that scheme. These best practice guidelines were drafted on the basis of the extensive knowledge and experience got from those annually organized CAH-schemes. In order to obtain the widest possible consultation with practicing laboratories the draft was therefore circulated twice by EMQN to all laboratories participating in the EQA-scheme for CAH genotyping and was updated by that input. The present guidelines address quality requirements for diagnostic molecular genetic laboratories, as well as criteria for CYP21A2 genotyping (including carrier-testing and prenatal diagnosis). A key aspect of that article is the use of appropriate methodologies (e.g., sequencing methods, MLPA (multiplex ligation dependent probe amplification), mutation specific assays) and respective limitations and analytical accuracy. Moreover, these guidelines focus on classification of variants, and the interpretation and standardization of the reporting of CYP21A2 genotyping results. In addition, the article provides a comprehensive list of common as well as so far unreported CYP21A2-variants.

Detection of a novel severe mutation affecting the CYP21A2 gene in a Chilean male with salt wasting congenital adrenal hyperplasia

PURPOSE

21-hydroxylase deficiency (21-OHD) is a congenital adrenal disease with more than 200 mutations published to date. The aim of this report is to describe a severe novel mutation of the CYP21A2 gene.

METHOD

We describe a case of a 39-year-old male diagnosed with a salt wasting congenital adrenal hyperplasia (SWCAH) due to 21-OHD. The genetic testing was done using a combination of three methods (PCR XL, SALSA-MLPA, and bidirectional sequencing) and finally an in silico analysis.

RESULTS

The genetic testing demonstrated three severe mutations of the CYP21A2 gene (p.Gln318*; c.290-13C>G; and p.Trp86*), being the last one a novel mutation not previously reported. The in silico modeling of the p.Trp86* (c.258G>A) showed a truncated CYP21A2 protein that loses all the main structural features required for activity, such as the HEM binding domain and the hormone binding site.

CONCLUSION

We present an adult man with an SWCAH due to 21-OHD who carried three severe mutations of the CYP21A2 gene, one of them, p.Trp86* (c.258G>A) has not been previously described.

Carriers of a Classic CYP21A2 Mutation Have Reduced Mortality: A Population-Based National Cohort Study

CONTEXT

Congenital adrenal hyperplasia (CAH) is a common monogenic recessive disorder. It has been suggested that CYP21A2 deficiency is common because carriers may have a survival advantage, 1 in 15,000 in most populations. Carriers of CYP21A2 mutations typically do not have clinical symptoms but have a defined phenotype with a more prompt cortisol response to ACTH.

OBJECTIVE

We investigated whether the mortality was lower, and determined the cause of death in carriers and population controls.

DESIGN

A total of 1143 obligate carriers of a CYP21A2 mutation (561 men) were identified from the Swedish National CAH Registry, encompassing >700 patients and the Multi-Generation Registry to identify their parents. The mortality and cause of death were identified through the Swedish Cause of Death Registry. The hazard ratios (HRs) and 95% CIs were calculated. The results were compared with controls from the general population, matched for sex and age.

RESULTS

The overall mortality was lower in carriers of a CYP21A2 mutation compared with the controls (HR 0.79; 95% CI, 0.678 to 0.917; P = 0.002). The difference was more marked among carriers of a more severe mutation. Infection as the cause of death was significantly lower (HR 0.65; 95% CI, 0.48 to 0.87; P < 0.01), particularly for death in pneumonia (HR 0.22; 95% CI, 0.06 to 0.88; P = 0.03). The lower overall mortality among women compared with men in the general population was confirmed among both carriers and controls.

CONCLUSION

Obligate CYP21A2 carriers of a classic mutation had a reduced mortality. Specifically, a possible reduced mortality due to pneumonia was seen.

Sexuality in Males With Congenital Adrenal Hyperplasia Resulting From 21-Hydroxylase Deficiency

Purpose

Although sexuality has been reported to be impaired in females with congenital adrenal hyperplasia (CAH) resulting from 21-hydroxylase deficiency, sexuality in males with CAH so far has remained largely unconsidered.

Patients

One of the largest European male cohorts of patients with CAH in which sexuality in male patients with CAH was assessed.

Methods

Sexuality was evaluated in 91 sexually active male patients with CAH using questionnaires investigating sexual orientation, age at sexual initiation, sexual activity, satisfaction with sex life, and sexual problems, such as fears or dislike of sexual activity, lack or excessive sexual desire, difficulties getting aroused or reaching an orgasm, premature ejaculation, and no or incomplete erection.

Results

Sexuality in male patients with CAH was similar to European reference populations. If sexuality problems were present, they were less frequently reported by the most severely affected CAH males. Adducing a holistic perspective, sexual problems showed substantial association to psychological problems, such as anxiety and depression.

Conclusions

Sexuality in male patients with CAH in general was unaffected and sexuality problems seemed to be associated in particular with psychological problems. Because sexual health is a key factor of general health, we recommend that sexuality as well as psychological issues explicitly should be addressed in health care of patients with a CAH diagnosis, independent of sex.

The Complexities in Genotyping of Congenital Adrenal Hyperplasia: 21-Hydroxylase Deficiency

The deficiency of 21-hydroxylase due to CYP21A2 pathogenic variants is a rather frequent disease with serious consequences, going from a real mortality risk to infertility and to milder symptoms, nevertheless important for affecting the patients' self-esteem. In the most severe cases life-threatening adrenal salt wasting crises may occur. Significant morbidity including the possibility of mistaken gender determination, precocious puberty, infertility and growth arrest with consequent short stature may also affect these patients. In the less severe cases milder symptoms like hirsutism will likely affect the image of the self with strong psychological consequences. Its diagnosis is confirmed by 17OH-progesterone dosages exceeding the cut-off value of 10/15 ng/ml but genotyping is progressively assuming an essential role in the study of these patients particularly in confirming difficult cases, determining some aspects of the prognosis and allowing a correct genetic counseling. Genotyping is a difficult process due to the occurrence of both a gene and a highly homologous pseudo gene. However, new tools are opening new possibilities to this analysis and improving the chances of a correct diagnosis and better understanding of the underlying mechanisms of the disease. Beyond the 10 classic pathogenic variants usually searched for in most laboratories, a correct analysis of 21OH-deficiency cases implies completely sequencing of the entire gene and the determination of gene duplications. These are now recognized to occur frequently and can be responsible for some false positive cases. And finally, because gene conversions can include several pathogenic variants one cannot be certain of identifying that both alleles are affected without studying parental DNA samples. A complete genotype characterization should be considered essential in the preparation for pregnancy, even in the case of parents with milder forms of the disease, or even just carriers, since it has been reported that giving birth to progeny with the severe classic forms occurs with a much higher frequency than expected.

Congenital Adrenal Hyperplasia Due to Steroid 21-Hydroxylase Deficiency: An Endocrine Society Clinical Practice Guideline

Objective

To update the congenital adrenal hyperplasia due to steroid 21-hydroxylase deficiency clinical practice guideline published by the Endocrine Society in 2010.

Conclusions

The writing committee presents updated best practice guidelines for the clinical management of congenital adrenal hyperplasia based on published evidence and expert opinion with added considerations for patient safety, quality of life, cost, and utilization.

CYP21A2 mutation update: Comprehensive analysis of databases and published genetic variants

Congenital adrenal hyperplasia (CAH) is a group of autosomal recessive disorders of adrenal steroidogenesis. Disorders in steroid 21-hydroxylation account for over 95% of patients with CAH. Clinically, the 21-hydroxylase deficiency has been classified in a broad spectrum of clinical forms, ranging from severe or classical, to mild late onset or non-classical. Known allelic variants in the disease causing CYP21A2 gene are spread among different sources. Until recently, most variants reported have been identified in the clinical setting, which presumably bias described variants to pathogenic ones, as those found in the CYPAlleles database. Nevertheless, a large number of variants are being described in massive genome projects, many of which are found in dbSNP, but lack functional implications and/or their phenotypic effect. In this work, we gathered a total of 1,340 GVs in the CYP21A2 gene, from which 899 variants were unique and 230 have an effect on human health, and compiled all this information in an integrated database. We also connected CYP21A2 sequence information to phenotypic effects for all available mutations, including double mutants in cis. Data compiled in the present work could help physicians in the genetic counseling of families affected with 21-hydroxylase deficiency.

Participation of adults with disorders/differences of sex development (DSD) in the clinical study dsd-LIFE: design, methodology, recruitment, data quality and study population

BACKGROUND

dsd-LIFE is a comprehensive cross-sectional clinical outcome study of individuals with disorders/differences of sex development (DSD). This study focuses on various rare genetic conditions characterized by impaired gonadal or adrenal functionality.

METHODS/DESIGN

The study aims to assess quality of life (QoL) as a measure of psychosocial adaptation, psychosexual and mental health aspects as major outcomes. Health status and functioning, medical and surgical therapies, participants' views on health care, psychological and social support, sociodemographic factors and their interrelations will be investigated as factors associated with the outcomes. In addition, ethical considerations in the field of DSD are addressed and previous experiences with health care were gathered. One thousand and forty participants with different DSD conditions were recruited by 14 study centres in 6 European countries (France, Germany, the Netherlands, Poland, Sweden and the United Kingdom) from February 2014 until September 2015. The conditions included were: Turner syndrome (n = 301); 45,X0/46,XY conditions (n = 45); Klinefelter syndrome (n = 218); 47,XYY (n = 1); 46,XY gonadal dysgenesis/ovotestes (n = 63); complete androgen insensitivity (CAIS) (n = 71); partial androgen insensitivity (PAIS) (n = 35) and androgen synthesis disorders (n = 20); severe hypospadias (n = 25); other or non-classified 46,XY DSD (n = 8); 46,XX congenital adrenal hyperplasia (CAH) (n = 226); 46,XX gonadal dysgenesis/ovotestis (n = 21); and 46,XX in males (n = 6). For an add-on study, 121 46,XY male-assigned individuals with CAH due to 21-hydroxylase deficiency were recruited. Mean age of participants' was 32.4 (+/- 13.6 years).

DISCUSSION

Participation was high in conditions not commonly described as DSD, such as Turner and Klinefelter syndromes or CAH. Recruitment of individuals with XY DSD conditions proved to be more difficult. The data collection of PROs resulted in high data quality. Within medical and physical examination data, more missings and/or inaccurate data were found than expected. The European dsd-LIFE study recruited and evaluated the largest cross-sectional sample of individuals with different conditions classified under the term DSD. The data from this large sample will provide a sufficient basis for evidence-based recommendations for improvement of clinical care of individuals affected by a DSD condition.

TRIAL REGISTRATION

German Clinical Trials Register DRKS00006072 .

Are carriers of CYP21A2 mutations less vulnerable to psychological stress? A population-based national cohort study

BACKGROUND

Congenital adrenal hyperplasia (CAH) is one of the most common monogenic autosomal recessive disorders with an incidence of one in 15 000. About one in 70 individuals in the general population are carriers of a severe CYP21A2 mutation. It has been suggested that this confers a survival advantage, perhaps as a result of increased activity in the hypothalamic-pituitary-adrenal axis. We investigated vulnerability to psychological stress in obligate carriers.

METHOD

The Swedish CAH Registry encompasses more than 600 patients. Parents, that is obligate carriers of the CYP21A2 mutation, were identified through the Multigeneration Register. The diagnosis of the child was used as the psychological stressor. Psychiatric diagnoses before and after the birth of a child with CAH were compared to those of controls derived from (i) the general population, (ii) parents of children with hypospadias and (iii) parents of children with diabetes mellitus type 1 (T1DM).

RESULTS

Parents of children with CAH had less risk of being diagnosed with any psychiatric disorder (OR, 0·6), an affective disorder (OR, 0·5) or substance misuse (OR, 0·5) after the diagnosis of the child, compared to the general population. Their risk was also decreased compared to parents of a child with hypospadias (OR, 0·6, 0·4 and 0·2, respectively) and parents of a child with T1DM (OR 0·7, 0·6 and 0·2, respectively). The CYP21A2 carriers had a lower risk of developing mood and stress-related disorders after the diagnosis of the child.

CONCLUSION

Obligate CYP21A2 carriers had a reduced risk of a psychiatric diagnosis and were less vulnerable to a psychologically stressful situation, at least with respect to receiving a psychiatric diagnosis. This indicates a better ability to cope with psychological stress among heterozygous carriers of severe CYP21A2 mutations, which may contribute to the apparent survival advantage.

The experience of women living with Congenital Adrenal Hyperplasia: impact of the condition and the care given

CONTEXT

Congenital adrenal hyperplasia (CAH) is caused most often by mutations in the CYP21A2 gene, resulting in cortisol and aldosterone deficiency and increased production of androgens.

OBJECTIVE

To describe how women with CAH experience their condition and the care given.

DESIGN, SETTING AND PARTICIPANTS

Semi-structured interviews with 13 adult Swedish women with CAH were transcribed. Data were analysed by qualitative content analysis to describe the variability in the experiences.

MAIN OUTCOME MEASURES

Qualitative evaluation of the participants' life experiences.

RESULTS

The participants' experiences of having CAH are described in four different categories. 1. Information comprises the experiences of interaction with healthcare providers, knowledge acquisition and information disclosure. 2. Exposure encompasses the experiences of genital examinations, the medical focus on the genitalia and of being photographed repeatedly. 3. Health covers the self-perceived experiences of having a medical condition that requires pharmacological treatment and sometimes surgery. 4. Research comprises the experiences of having a scientifically well-studied condition. Different experiences of shame reoccur in all categories, thus forming the latent theme.

CONCLUSION

The experience of living with congenital adrenal hyperplasia can be facilitated by increased information and by acknowledging that women with CAH are a heterogeneous group with individual needs. Shame may be counterbalanced by increased parental support and increased knowledge among healthcare personnel aimed at providing children with continuous support and coping strategies during their upbringing. Based on the identified themes in this study, there are several research avenues to pursue in the future.

A de novo mutation in CYP21A2 gene in a case of in vitro fertilization

Congenital adrenal hyperplasia, one of the most frequent autosome recessive disorders, is caused by defects in steroidogenic enzymes involved in the cortisol biosynthesis. Approximately 95% of the cases are caused by abnormal function of the 21-hydroxylase enzyme. This deficiency leads to androgen excess, consequently, to virilization and rapid somatic growth with accelerated skeletal maturation. Mutations in CYP21A2 are responsible for different forms of 21-hydroxylase deficiency. Mild impairment in the enzymatic activity causes the non-classic or late-onset congenital adrenal hyperplasia that is observed with a prevalence of 1 in 1000 subjects in different populations. The present paper describes a de novo mutation that occurred in the paternal meiosis. The child, who was conceived by in vitro fertilization, presented with precocious puberty and diagnosed with non-classical 21-hydroxylase deficiency. DNA sequencing showed the compound heterozygosis for a de novo CYP21A1P/A2 chimeric gene and the p.Val281Leu mutation inherited from her mother, who was heterozygous for the mutation. The chimeric gene showed pseudogene-derived sequence from 5′-end to intron 3 and CYP21A2 sequences from intron 3 to 3′-end of the gene. Sequencing analysis of the father did not show any mutation. The multiplex ligation-dependent probe amplification (MLPA) assay did not indicate loss of DNA discarding gene deletion but confirmed the chimeric gene. In addition, supernumerary copies of CYP21A1P were observed for both parents and for the affect child. Since paternity has been confirmed, those results suggest that a de novo large gene conversion in the paternal meiosis could have occurred by misalignment of alleles bearing different copy numbers of genes in CYP21 locus.

In vitro functional studies of rare CYP21A2 mutations and establishment of an activity gradient for nonclassic mutations improve phenotype predictions in congenital adrenal hyperplasia

BACKGROUND

A detailed genotype-phenotype evaluation is presented by studying the enzyme activities of five rare amino acid substitutions (Arg233Gly, Ala265Ser, Arg341Trp, Arg366Cys and Met473Ile) identified in the CYP21A2 gene in patients investigated for Congenital adrenal hyperplasia (CAH).

OBJECTIVE

To investigate whether the mutations identified in the CYP21A2 gene are disease causing and to establish a gradient for the degree of enzyme impairment to improve prediction of patient phenotype.

DESIGN AND PATIENTS

The CYP21A2 genes of seven patients investigated for CAH were sequenced and five mutations were identified. The mutant proteins were expressed in vitro in COS-1 cells, and the enzyme activities towards the two natural substrates were determined to verify the disease-causing state of the mutations. The in vitro activities of these rare mutations were also compared with the activities of four mutations known to cause nonclassic CAH (Pro30Leu, Val281Leu, Pro453Ser and Pro482Ser) in addition to an in silico structural evaluation of the novel mutants.

MAIN OUTCOME MEASURE

To verify the disease-causing state of novel mutations.

RESULTS

Five CYP21A2 mutations were identified (Arg233Gly, Ala265Ser, Arg341Trp, Arg366Cys and Met473Ile). All mutant proteins exhibited enzyme activities above 5%, and four mutations were classified as nonclassic and one as a normal variant. By comparing the investigated protein changes with four common mutations causing nonclassic CAH, a gradient for the degree of enzyme impairment could be established. Studying rare mutations in CAH increases our knowledge regarding the molecular mechanisms that render a mutation pathogenic. It also improves phenotype predictions and genetic counselling for future generations.

Suboptimal psychosocial outcomes in patients with congenital adrenal hyperplasia: epidemiological studies in a nonbiased national cohort in Sweden

CONTEXT

Congenital adrenal hyperplasia (CAH), CYP21A2 deficiency, results in cortisol and aldosterone deficiency and increased production of androgens, with a good genotype phenotype correlation.

OBJECTIVE

The objective of the investigation was to study psychosocial outcomes in relation to clinical severity, CYP21A2 genotype, in men and women.

DESIGN

This was an epidemiological study with a matched case control design.

SETTING

The setting of the study was all known CAH patients in Sweden.

PARTICIPANTS

Five hundred eighty-eight patients, more than 80% with known severity of CAH, and 100 controls per patient matched for sex, year, and place of birth participated in the study.

MAIN OUTCOME AND MEASURES

Proxies for quality of life were selected: level of education, employment, income, sick leave, disability pension, marriage, and children.

RESULTS

Women with salt-wasting (SW) CAH had completed primary education less often [odds ratio (OR) 0.3], not explained by neonatal salt crisis or hypoglycemia because the men did not differ from controls. Men and women in the less severe I172N genotype group were more likely to have an academic education (OR 1.8). SW women were more likely to have an income in the top 20th percentile (OR 2.0). Both men and women had more disability pension (OR 1.5) and sick leave (OR 1.7). The men more often had long-lasting employment (OR 3.1). Men were more often (OR 1.6) and women were less often married (OR 0.7). Patients had children less often (OR 0.3).

CONCLUSIONS

This study shows important outcome differences regarding education; employment; marriage and fertility, depending on sex; and severity of CAH. The mechanisms behind this and the increased risk for sick leave or disability pension in both men and women should be identified to improve medical and psychological care.

Functional studies of novel CYP21A2 mutations detected in Norwegian patients with congenital adrenal hyperplasia

In about 95% of cases, congenital adrenal hyperplasia (CAH) is caused by mutations in CYP21A2 gene encoding steroid 21-hydroxylase (21OH). Recently, we have reported four novel CYP21A2 variants in the Norwegian population of patients with CAH, of which p.L388R and p.E140K were associated with salt wasting (SW), p.P45L with simple virilising (SV) and p.V211M+p.V281L with SV to non-classical (NC) phenotypes. We aimed to characterise the novel variants functionally utilising a newly designed in vitro assay of 21OH enzyme activity and structural simulations and compare the results with clinical phenotypes. CYP21A2 mutations and variants were expressed in vitro. Enzyme activity was assayed by assessing the conversion of 17-hydroxyprogesterone to 11-deoxycortisol by liquid chromatography tandem mass spectroscopy. PyMOL 1.3 was used for structural simulations, and PolyPhen2 and PROVEAN for predicting the severity of the mutants. The CYP21A2 mutants, p.L388R and p.E140K, exhibited 1.1 and 11.3% of wt 21OH enzyme activity, respectively, in vitro. We could not detect any functional deficiency of the p.P45L variant in vitro; although prediction tools suggest p.P45L to be pathogenic. p.V211M displayed enzyme activity equivalent to the wt in vitro, which was supported by in silico analyses. We found good correlations between phenotype and the in vitro enzyme activities of the SW mutants, but not for the SV p.P45L variant. p.V211M might have a synergistic effect together with p.V281L, explaining a phenotype between SV and NC CAH.

One hundred years of congenital adrenal hyperplasia in Sweden: a retrospective, population-based cohort study

BACKGROUND

Congenital adrenal hyperplasia due to 21-hydroxylase deficiency results in cortisol and aldosterone deficiency and is, in its most severe form, lethal. We aimed to assess the effect of historical medical improvements in the care of patients with this disorder over time and to assess the effects of neonatal screening in Sweden.

METHODS

For this retrospective, population-based cohort study, we collected data for all known patients with congenital adrenal hyperplasia in Sweden between 1910 and 2011 [corrected]. Data sources included the registry at the Swedish national screening laboratory, patients identified via the Swedish neonatal screening programme, late-diagnosed patients reported to the laboratory, and patients who underwent genetic diagnostics or became known to us through clinical contacts. All known patients were included in a population-based cohort study of the distribution of clinical severity, genotype, sex, and the effect of nationwide neonatal screening.

FINDINGS

We identified 606 patients with the disorder, born between 1915 and 2011. The CYP21A2 genotype (conferring deficiency of 21-hydroxylase) was known in 490 patients (81%). The female-to-male ratio was 1·25 in the whole cohort, but close to 1 in patients detected by the screening. We noted a sharp increase in the number of patients diagnosed in the 1960s and 1970s, and after the introduction of neonatal screening in 1986 the proportion of patients with the salt-wasting form of congenital adrenal hyperplasia increased in both sexes, from 114 (47%) of 242 individuals between 1950 and 1985 to 165 (57%) of 292 individuals between 1986 and 2011 (p=0·038). On average, five to ten children were missed every year before 1970. The non-classic form of the disorder was diagnosed more often in women than in men, which accounts for the female preponderance in our cohort.

INTERPRETATION

Our findings suggest that, contrary to current belief, boys and girls with salt-wasting congenital adrenal hyperplasia were equally missed clinically. Neonatal screening improved detection of the salt-wasting form in girls as well as boys, saving lives in both sexes. The non-classic form was diagnosed more often in women than it was in men, leading to the female preponderance in this cohort.

FUNDING

The Swedish Research Council, the Centre of Gender Medicine at Karolinska Institutet, the Stockholm County Council, the Sällskapet Barnavård Foundation, the Stiftelsen Samariten Foundation, the Stiftelsen Frimurare Barnhuset Foundation, and the Novo Nordisk Foundation.

Congenital adrenal hyperplasia

Congenital adrenal hyperplasia consists of a heterogenous group of inherited disorders due to enzymatic defects in the biosynthetic pathway of cortisol and/or aldosterone. This results in glucocorticoid deficiency, mineralocorticoid deficiency, and androgen excess. 95% of CAH cases are due to 21-hydroxylase deficiency. Clinical forms range from the severe, classical CAH associated with complete loss of enzyme function, to milder, non-classical forms (NCAH). Androgen excess affects the pilosebaceous unit, causing cutaneous manifestations such as acne, androgenetic alopecia and hirsutism. Clinical differential diagnosis between NCAH and polycystic ovary syndrome may be difficult. In this review, the evaluation of patients with suspected CAH, the clinical presentation of CAH forms, with emphasis on the cutaneous manifestations of the disease, and available treatment options, will be discussed.

Genetic, anthropometric and metabolic features of adult Norwegian patients with 21-hydroxylase deficiency

OBJECTIVE

The aim of this study was to determine the genetic, anthropometric and metabolic features in an unselected population of adult Norwegian patients with 21-hydroxylase deficiency (21OHD). PATIENTS, METHODS AND DESIGN: Sixty-four 21OHD patients participated (23 men and 41 women; median age 38.5 years; range 19-72 years) in a cross-sectional study including DNA sequencing of CYP21A2, anthropometric measurements including dual X-ray absorptiometry scanning and biochemical analyses. The results were compared with reference cohorts from the general population.

RESULTS

We identified four novel and plausibly disease-causing CYP21A2 mutations. Gene deletions/conversions (42.1% of alleles), the splice mutation I2 splice (23.0%) and point mutation I172 N (22.2%) were common. The genotype corresponded to clinical phenotype in 92% of the patients. The prevalence of osteopenia was 48% in males and 34% in females. Both men and women had normal BMI but markedly increased fat mass compared with the normal population. Diastolic blood pressure was higher than normal. Thirty-nine per cent of the women had testosterone levels above the normal range; 13% of the men had testosterone levels below normal. Reduced final height was more pronounced in men (median -11.2 cm, -1.77 SDS) than in women (-6.3 cm, -1.07 SDS).

CONCLUSIONS

In this population-based survey of 21OHD, we identified four novel mutations and high concordance between genotype and phenotype. The patients had increased fat mass, increased diastolic blood pressure, reduced final height and high frequency of osteopenia among males. These results show unfavourable metabolic features in 21OHD patients indicating a need for improvement of treatment and follow-up.

Nonclassic congenital adrenal hyperplasia

PURPOSE OF REVIEW

Late-onset or nonclassic congenital adrenal hyperplasia (NCAH) due to 21-hydroxylase deficiency is one of the most common autosomal recessive disorders. Reported prevalence ranges from 1 in 30 to 1 in 1000. Affected individuals typically present due to signs and symptoms of androgen excess. The purpose of this review is to provide current information regarding the pathophysiology, molecular genetics, and management of this common disorder.

RECENT FINDINGS

Subfertility and the consequences of elevated progesterone concentrations have been increasingly documented for women with NCAH. Although testicular adrenal rest tumors (TARTs) are more common in men with classical congenital adrenal hyperplasia, oligospermia and TARTs have been described in men with NCAH. The phenotypic spectrum of defects in other components of the steroidogenic pathway such as P450 oxidoreductase and steroidogenic acute regulatory protein has been expanded to include milder forms.

SUMMARY

Treatment needs to be directed toward the symptoms. Goals of treatment include normal linear growth velocity, normal rate of skeletal maturation, 'on-time' puberty, regular menstrual cycles, prevention of or limited progression of hirsutism and acne, and fertility. Treatment needs to be individualized and should not be initiated merely to decrease abnormally elevated hormone concentrations.

Identification and functional characterization of a novel mutation P459H and a rare mutation R483W in the CYP21A2 gene in two Chinese patients with simple virilizing form of congenital adrenal hyperplasia

BACKGROUND

Steroid 21-hydroxylase deficiency (21-OHD) is the most common cause of congenital adrenal hyperplasia (CAH). Clinically, 21-OHD is categorized into saltwasting, simple-virilizing (SV), and non-classical (NC) forms. It is well recognized that a good correlation exists between genotype and clinical phenotype of CAH.

AIM

The aim of this study was to identify CYP21A2 gene mutations in 2 Chinese patients with SV CAH along with their parents and other family members.

STUDY DESIGN AND RESULTS

By direct sequencing the CYP21A2 gene, a novel mutation, P459H, was detected in 1 patient; and a previously described uncharacterized mutation, R483W, was found in another patient. The 21-hydroxylase activities were determined by measuring the converting rate of progesterone to 11-deoxycorticosterone in COS-7 cells overexpressed with these mutated proteins. Our results revealed significantly reduced enzyme activity in both mutants: residual activity of P459H and R483W towards progesterone was 6.8%±2.1 and 2.9%±1.5, respectively compared to that of the wild type. We also demonstrated the loss of 21-hydroxylase activities using a three-dimensional model of CYP21A2.

CONCLUSION

Both R483W and P459H mutations are confirmed to be related to NC CAH by in vitro functional study, with phenotype variance of R483W in Tunisian and Chinese patients. This study will aid in predicting disease severity and in facilitating family genetic counseling.

Steroid 21 hydroxylase deficiency congenital adrenal hyperplasia

Steroid 21 hydroxylase deficiency is the most common form of congenital adrenal hyperplasia (CAH). The severity of this disorder depends on the extent of impaired enzymatic activity, which is caused by various mutations of the 21 hydroxylase gene. This article reviews adrenal steroidogenesis and the pathophysiology of 21 hydroxylase deficiency. The three forms of CAH are then discussed in terms of clinical presentation, diagnosis and treatment, and genetic basis. Prenatal diagnosis and treatment are also reviewed. The goal of therapy is to correct the deficiency in cortisol secretion and suppress androgen overproduction. Glucocorticoid replacement has been the mainstay of treatment for CAH, but new treatment strategies continue to be developed and studied.

Relationship of CYP21A2 genotype and serum 17-hydroxyprogesterone and cortisol levels in a large cohort of Italian children with premature pubarche

OBJECTIVE

Premature pubarche (PP) is the most frequent sign of nonclassic congenital adrenal hyperplasia (NCCAH) due to 21-hydroxylase deficiency in childhood. The aim of this study was to assess the relationship between the CYP21A2 genotype and baseline and ACTH-stimulated 17-hydroxyprogesterone (17-OHP) and cortisol serum levels in patients presenting with PP.

PATIENTS AND METHODS

A total of 152 Italian children with PP were studied. Baseline and ACTH-stimulated 17-OHP and cortisol serum levels were measured and CYP21A2 gene was genotyped in all subjects.

RESULTS

Baseline and ACTH-stimulated serum 17-OHP levels were significantly higher in NCCAH patients than in both heterozygotes and children with idiopathic PP (IPP). Of the patient population, four NCCAH patients (7.3%) exhibited baseline 17-OHP values <2 ng/ml (6 nmol/l). An ACTH-stimulated 17-OHP cutoff level of 14 ng/ml (42 nmol/l) identified by the receiver-operating characteristics curves showed the best sensitivity (90.9%) and specificity (100%) in distinguishing NCCAH patients. This value, while correctly identifying all unaffected children, missed 9% of affected individuals. Cortisol response to ACTH stimulation was <18.2 μg/dl (500 nmol/l) in 14 NCCAH patients (28%) and none of the heterozygotes or IPP children. Among the 55 NCCAH patients, 54.5% were homozygous for mild CYP21A2 mutations, 41.8% were compound heterozygotes for one mild and one severe CYP21A2 gene mutations, and 3.6% had two severe CYP21A2 gene mutations.

CONCLUSION

In children with PP, baseline 17-OHP levels are not useful to rule out the diagnosis of NCCAH, which is accomplished by means of ACTH testing only. The different percentages of severe and mild CYP21A2 gene mutations found in PP children compared with adult NCCAH patients is an indirect evidence that the enzyme defect is under-diagnosed in childhood, and it might not lead to the development of hyperandrogenic symptoms in adulthood. Stress-dose glucocorticoids should be considered in patients with suboptimal cortisol response to ACTH stimulation.

Congenital adrenal hyperplasia

Congenital adrenal hyperplasia (CAH) due to P450c21 (21-hydroxylase deficiency) is a common autosomal recessive disorder. This disorder is due to mutations in the CYP21A2 gene which is located at chromosome 6p21. The clinical features reflect the magnitude of the loss of function mutations. Individuals with complete loss of function mutations usually present in the neonatal period. The clinical features of individuals with mild loss of function mutations are predominantly due to androgen excess rather than adrenal insufficiency leading to an ascertainment bias favoring diagnosis in females. Treatment goals include normal linear growth velocity and "on-time" puberty in affected children. For adolescent and adult women, treatment goals include regularization of menses, prevention of progression of hirsutism, and fertility. This article will review key aspects regarding pathophysiology, diagnosis, and treatment of CAH.

The molecular biology, biochemistry, and physiology of human steroidogenesis and its disorders

Steroidogenesis entails processes by which cholesterol is converted to biologically active steroid hormones. Whereas most endocrine texts discuss adrenal, ovarian, testicular, placental, and other steroidogenic processes in a gland-specific fashion, steroidogenesis is better understood as a single process that is repeated in each gland with cell-type-specific variations on a single theme. Thus, understanding steroidogenesis is rooted in an understanding of the biochemistry of the various steroidogenic enzymes and cofactors and the genes that encode them. The first and rate-limiting step in steroidogenesis is the conversion of cholesterol to pregnenolone by a single enzyme, P450scc (CYP11A1), but this enzymatically complex step is subject to multiple regulatory mechanisms, yielding finely tuned quantitative regulation. Qualitative regulation determining the type of steroid to be produced is mediated by many enzymes and cofactors. Steroidogenic enzymes fall into two groups: cytochrome P450 enzymes and hydroxysteroid dehydrogenases. A cytochrome P450 may be either type 1 (in mitochondria) or type 2 (in endoplasmic reticulum), and a hydroxysteroid dehydrogenase may belong to either the aldo-keto reductase or short-chain dehydrogenase/reductase families. The activities of these enzymes are modulated by posttranslational modifications and by cofactors, especially electron-donating redox partners. The elucidation of the precise roles of these various enzymes and cofactors has been greatly facilitated by identifying the genetic bases of rare disorders of steroidogenesis. Some enzymes not principally involved in steroidogenesis may also catalyze extraglandular steroidogenesis, modulating the phenotype expected to result from some mutations. Understanding steroidogenesis is of fundamental importance to understanding disorders of sexual differentiation, reproduction, fertility, hypertension, obesity, and physiological homeostasis.

Structure-based analysis of five novel disease-causing mutations in 21-hydroxylase-deficient patients

Congenital adrenal hyperplasia (CAH) due to 21-hydroxylase deficiency is the most frequent inborn error of metabolism, and accounts for 90–95% of CAH cases. The affected enzyme, P450C21, is encoded by the CYP21A2 gene, located together with a 98% nucleotide sequence identity CYP21A1P pseudogene, on chromosome 6p21.3. Even though most patients carry CYP21A1P-derived mutations, an increasing number of novel and rare mutations in disease causing alleles were found in the last years. In the present work, we describe five CYP21A2 novel mutations, p.R132C, p.149C, p.M283V, p.E431K and a frameshift g.2511_2512delGG, in four non-classical and one salt wasting patients from Argentina. All novel point mutations are located in CYP21 protein residues that are conserved throughout mammalian species, and none of them were found in control individuals. The putative pathogenic mechanisms of the novel variants were analyzed in silico. A three-dimensional CYP21 structure was generated by homology modeling and the protein design algorithm FoldX was used to calculate changes in stability of CYP21A2 protein. Our analysis revealed changes in protein stability or in the surface charge of the mutant enzymes, which could be related to the clinical manifestation found in patients.

Comprehensive genetic analysis of 182 unrelated families with congenital adrenal hyperplasia due to 21-hydroxylase deficiency

BACKGROUND

Genetic analysis is commonly performed in patients with congenital adrenal hyperplasia (CAH) due to 21-hydroxylase deficiency.

STUDY OBJECTIVE

The objective of the study was to describe comprehensive CYP21A2 mutation analysis in a large cohort of CAH patients.

METHODS

Targeted CYP21A2 mutation analysis was performed in 213 patients and 232 parents from 182 unrelated families. Complete exons of CYP21A2 were sequenced in patients in whom positive mutations were not identified by targeted mutation analysis. Copy number variation and deletions were determined using Southern blot analysis and PCR methods. Genotype was correlated with phenotype.

RESULTS

In our heterogeneous U.S. cohort, targeted CYP21A2 mutation analysis did not identify mutations on one allele in 19 probands (10.4%). Sequencing identified six novel mutations (p.Gln262fs, IVS8+1G>A, IVS9-1G>A, p.R408H, p.Gly424fs, p.R426P) and nine previously reported rare mutations. The majority of patients (79%) were compound heterozygotes and 69% of nonclassic (NC) patients were compound heterozygous for a classic and a NC mutation. Duplicated CYP21A2 haplotypes, de novo mutations and uniparental disomy were present in 2.7% of probands and 1.9 and 0.9% of patients from informative families, respectively. Genotype accurately predicted phenotype in 90.5, 85.1, and 97.8% of patients with salt-wasting, simple virilizing, and NC mutations, respectively.

CONCLUSIONS

Extensive genetic analysis beyond targeted CYP21A2 mutational detection is often required to accurately determine genotype in patients with CAH due to the high frequency of complex genetic variation.

Congenital adrenal hyperplasia due to steroid 21-hydroxylase deficiency: an Endocrine Society clinical practice guideline

OBJECTIVE

We developed clinical practice guidelines for congenital adrenal hyperplasia (CAH).

PARTICIPANTS

The Task Force included a chair, selected by The Endocrine Society Clinical Guidelines Subcommittee (CGS), ten additional clinicians experienced in treating CAH, a methodologist, and a medical writer. Additional experts were also consulted. The authors received no corporate funding or remuneration.

CONSENSUS PROCESS

Consensus was guided by systematic reviews of evidence and discussions. The guidelines were reviewed and approved sequentially by The Endocrine Society's CGS and Clinical Affairs Core Committee, members responding to a web posting, and The Endocrine Society Council. At each stage, the Task Force incorporated changes in response to written comments.

CONCLUSIONS

We recommend universal newborn screening for severe steroid 21-hydroxylase deficiency followed by confirmatory tests. We recommend that prenatal treatment of CAH continue to be regarded as experimental. The diagnosis rests on clinical and hormonal data; genotyping is reserved for equivocal cases and genetic counseling. Glucocorticoid dosage should be minimized to avoid iatrogenic Cushing's syndrome. Mineralocorticoids and, in infants, supplemental sodium are recommended in classic CAH patients. We recommend against the routine use of experimental therapies to promote growth and delay puberty; we suggest patients avoid adrenalectomy. Surgical guidelines emphasize early single-stage genital repair for severely virilized girls, performed by experienced surgeons. Clinicians should consider patients' quality of life, consulting mental health professionals as appropriate. At the transition to adulthood, we recommend monitoring for potential complications of CAH. Finally, we recommend judicious use of medication during pregnancy and in symptomatic patients with nonclassic CAH.

Sexual function and surgical outcome in women with congenital adrenal hyperplasia due to CYP21A2 deficiency: clinical perspective and the patients' perception

CONTEXT

Females with congenital adrenal hyperplasia (CAH) due to a CYP21A2 deficiency are exposed to androgens during fetal development, resulting in virilization of the external genitalia. Little is known about how these women feel that the disease has affected their lives regarding surgery and psychosexual adaptation.

OBJECTIVE

Our objective was to investigate the correlation between the surgical results, the self-perceived severity of the disease, and satisfaction with sexual life and relate the results to the CYP21A2 genotype.

DESIGN AND PARTICIPANTS

Sixty-two Swedish women with CAH and age-matched controls completed a 120-item questionnaire, and a composite score for sexual function was constructed. The surgical outcome, including genital appearance and clitoral sensitivity, was evaluated by clinical examination. The patients were divided into four CYP21A2 genotype groups.

RESULTS

The sexual function score, but not for genital appearance, was higher in the patients satisfied with their sexual life. This was also true of the patients who were satisfied with the surgical result. There were discrepancies between the patients' perception of the impact of the condition on their sexual life and what health professionals would assume from clinical examination. The patients in the null genotype group scored lower on sexual function and satisfaction with their sexual life and had more surgical complications, also compared with the slightly less severe I2-splice genotype group.

CONCLUSION

Our data show that the null genotype group was considerably more affected by the condition than the other groups and should be regarded as a subgroup, both psychologically and from a surgical perspective. Genotyping adds clinically valuable information.

Nonclassic congenital adrenal hyperplasia

Nonclassic congenital adrenal hyperplasia (NCAH) due to P450c21 (21-hydroxylase deficiency) is a common autosomal recessive disorder. This disorder is due to mutations in the CYP21A2 gene which is located at chromosome 6p21. The clinical features predominantly reflect androgen excess rather than adrenal insufficiency leading to an ascertainment bias favoring diagnosis in females. Treatment goals include normal linear growth velocity and "on-time" puberty in affected children. For adolescent and adult women, treatment goals include regularization of menses, prevention of progression of hirsutism, and fertility. This paper will review key aspects regarding pathophysiology, diagnosis, and treatment of NCAH.

Steroid 21 hydroxylase deficiency congenital adrenal hyperplasia

Steroid 21 hydroxylase deficiency is the most common form of congenital adrenal hyperplasia (CAH). The severity of this disorder depends on the extent of impaired enzymatic activity, which is caused by various mutations of the 21 hydroxylase gene. This article reviews adrenal steroidogenesis and the pathophysiology of 21 hydroxylase deficiency. The three forms of CAH are then discussed in terms of clinical presentation, diagnosis and treatment, and genetic basis. Prenatal diagnosis and treatment are also reviewed. The goal of therapy is to correct the deficiency in cortisol secretion and suppress androgen overproduction. Glucocorticoid replacement has been the mainstay of treatment for CAH, but new treatment strategies continue to be developed and studied.

Methods for the analysis of large gene deletions and their application in some monogenic disorders

Számos monogénesen öröklődő kórképben a betegséget okozó gén teljes vagy részleges deletiója, illetve kópiaszámának megváltozása patogenetikai tényezőként jön számításba. A direkt DNS-szekvenálás nem alkalmas a gén nagy deletiójának, illetve kópiaszám-változásának kimutatására. Az összefoglalóban a szerzők áttekintik a nagy géndeletio vizsgálómódszereit, és két, monogénesen öröklődő betegségben végzett saját vizsgálataik példáján keresztül bemutatják a módszerek gyakorlati alkalmazásának lehetőségeit. Vázolják a géndeletio-vizsgálat hagyományos (kromoszóma-sávtechnika, Southern-blot, fluoreszcens in situ hibridizáció) és polimeráz láncreakcióra alapozott módszereit (denaturáló nagy felbontóképességű folyadékkromatográfia, kvantitatív valós idejű polimeráz láncreakció, mikroszatellitamarker-analízis, multiplex amplifikálhatópróba-hibridizáció, multiplex ligatióspróba-analízis), valamint a technikai és informatikai haladás legújabb vívmányait (komparatív genomhibridizálás, „array” analízis). Saját vizsgálataikban von Hippel–Lindau-szindrómában szenvedő betegekben kvantitatív valós idejű polimeráz láncreakció és multiplex ligatióspróba-amplifikálás alkalmazásával bemutatják a VHL, illetve congenitalis adrenalis hyperplasiás betegekben a CYP21A2 géndeletio-vizsgálat eredményeit és ezek klinikai jelentőségét.

Gender role behavior, sexuality, and psychosocial adaptation in women with congenital adrenal hyperplasia due to CYP21A2 deficiency

CONTEXT

Gender-atypical behavior has been described in young girls as well as in women with congenital adrenal hyperplasia (CAH) due to a CYP21A2 deficiency.

OBJECTIVE

The aim of the study was to assess health-related, psychosexual, and psychosocial parameters and correlate the results to CYP21A2 genotype.

DESIGN AND PARTICIPANTS

Sixty-two Swedish women with CAH and age-matched controls completed a 120-item questionnaire and a validated quality of life instrument [psychological general well-being (PGWB) formula] to identify psychosexual and psychosocial parameters. The patients were divided into four CYP21A2 genotype groups.

RESULTS

The women with CAH held more male-dominant occupations (30%) compared to controls (13%) (P = 0.04), especially those in the null genotype group (55%) (P = 0.006). They also reported a greater interest in rough sports (74%) compared to controls (50%) (P = 0.007). Eight women with CAH (14%) reported a prime interest in motor vehicles, compared to none of the controls (P = 0.002). Non-heterosexual orientation was reported by 19% of women with CAH (P = 0.005), 50% in the null genotype group (P = 0.0001), 30% in I2 splice (NS), and 5% in I172N (NS). PGWB total score did not differ between patients and controls.

CONCLUSION

We identified increased gender-atypical behavior in women with CAH that could be correlated to the CYP21A2 genotype. This speaks in favor of dose-dependent effects of prenatal androgens on the development of higher brain functions. The impact of the disease on upbringing and interpersonal relationships did not correlate with disease severity, indicating that other factors, such as coping strategies, are important for psychosocial adaptation. This illustrates the need for psychological support to parents and patients.

Congenital adrenal hyperplasia in adults

Hyperandrogenism in congenital adrenal hyperplasia (CAH) results from overstimulation of adrenocorticotropic-driven androgen production in the adrenal cortex due to lack of cortisol feedback. The classical form is characterized by more-severe symptoms of hyperandrogenism, including virilization of the female genitalia. The milder nonclassical form presents with postnatal symptoms of hyperandrogenism. Presenting symptoms in adulthood may include acne, male-pattern alopecia, hirsutism, irregular menses/amenorrhea or infertility. The goal of therapy in CAH is to both correct the deficiency in cortisol secretion and suppress androgen overproduction. Glucocorticoid replacement has been the mainstay of treatment for CAH but new treatment strategies continue to be developed and studied.

In Vitro Enzyme Assay of CYP21A2 Mutation (R483Q) by A Novel Method Using Liquid Chromatography-Electrospray Ionization Tandem Mass Spectrometry (LC-ESI-MS/MS)

Congenital adrenal hyperplasia (CAH) is one of the most common autosomal recessive disorders in humans, and 21-hydroxylase deficiency (21-OHD) accounts for 90 to 95% of all cases of CAH. Approximately 95% mutations are a consequence of recombination between the CYP21A2 and its highly homologous pseudogene CYP21A1P. Recently, other rare mutations have been identified, increasing the number of reported mutations to more than eighty. The in vitro enzyme assay for the detection of mutated 21-hydroxylase is a well-established method. In this study, we report the characterization of the R483Q mutation using a novel in vitro enzyme assay, liquid chromatography-electrospray ionization tandem mass spectrometry (LC-ESI-MS/MS). With this system, we evaluated the activity of the R483Q mutation. The enzyme activities of 21-hydroxylase in the convertion of progesterone to deoxycorticosterone (DOC), and 17-hydroxyprogesterone (17-OHP) to 11-deoxycortisol (11-DOF), were measured as 2.00 ± 0.25% and 1.89 ± 0.30% of the wild type, respectively. This result was in agreement with that of a previous report, which measured the activities using the (3)H labeled steroid assay. Our results suggest that the R483Q mutation is compatible with the simple virilizing form of 21-OHD and that the LC-ESI-MS/MS assay using picolinoyl derivatives is an alternative to the existing (3)H-labeled steroid assay for the characterization of the CYP21A2 mutation.

A 31-year-old woman with infertility and polycystic ovaries diagnosed with non-classic congenital adrenal hyperplasia due to a novel CYP21 mutation

A 31-yr-old woman presenting with a history of hirsutism, amenorrhea, and infertility was previously assumed to have polycystic ovary syndrome. A new gynecological-endocrine evaluation demonstrated elevated testosterone/SHBG ratio, serum 17-hydroxyprogesterone (17-OHP), and urinary pregnantriol. She was diagnosed with non-classic congenital adrenal hyperplasia. In spite of treatment with dexamethasone and fludrocortisone in doses that suppressed adrenal androgens and 17-OHP into normal range or below, she did not ovulate. Clomiphene citrate and then FSH/hCG treatment in several cycles gave no consistent ovulation. Progesterone levels remained elevated throughout the cycles indicating a possible contribution from the adrenals. Oral glucose tolerance was normal, but the homeostasis model assessment index indicated insulin resistance. With metformin 1500 mg daily the index decreased remarkably from 2.77 to 0.96 with a few ovulations but no pregnancy occurred. Three cycles of IVF treatment thereafter were unsuccessful. Three months after the last in vitro fertilization (IVF) cycle, still on dexamethasone, fludrocortisone, and metformin, her menstruations became regular and she thereafter became pregnant. During pregnancy metformin was discontinued and dexamethasone replaced with prednisolone. Mild gestational diabetes developed and insulin was given. A healthy boy was born at term by elective Cesarean section. A CYP21- gene analysis had not indicated any of the known mutations but after gene sequencing a novel mutation was found, namely R233G. This case confirms the necessity of adding an analysis of 17-OHP when evaluating women with hirsutism and menstrual disturbances and if an elevated value is found, the advantage of performing a mutation analysis to facilitate counseling and decisions on treatment.

Recent advances in diagnosis, treatment, and outcome of congenital adrenal hyperplasia due to 21-hydroxylase deficiency

Congenital adrenal hyperplasia (CAH) due to 21-hydroxylase deficiency (21-OHD) is an autosomal-recessive disease causing cortisol deficiency, aldosterone deficiency and hyperandrogenism. Diagnosis of 21-OHD is confirmed by steroid analysis in newborn screening or later on. Standard medical treatment consists of oral glucocorticoid and mineralocorticoid administration in order to suppress adrenal androgens and to compensate for adrenal steroid deficiencies. However, available treatment is far from ideal, and not much is known about the long-term outcome in CAH as trials in patients in adulthood or old age are rare. Here we briefly describe the pathophysiology, clinical picture, genetics and epidemiology of 21-OHD. This is followed by a comprehensive review of the recent advances in diagnosis, treatment and outcome. Novel insights have been gained in the fields of newborn screening, specific steroid measurement utilizing mass spectrometry, genetics, glucocorticoid stress dosing, additive medical therapy, prenatal treatment, side-effects of medical treatment, adrenomedullary involvement, metabolic morbidity, fertility and gender identity. However, many issues are still unresolved, and novel questions, which will have to be answered in the future, arise with every new finding.

Three novel CYP21A2 mutations and their protein modelling in patients with classical 21-hydroxylase deficiency from northeastern Iran

OBJECTIVE

Congenital adrenal hyperplasia (CAH) refers to a group of autosomal recessive disorders frequently caused by mutations in the steroid 21-hydroxylase gene (CYP21A2). We describe three novel CYP21A2 mutations in CAH patients.

DESIGN AND METHODS

Sequence analysis of the entire CYP21A2 gene followed by molecular modelling was performed in three unrelated classical CAH patients of northeastern Iranian origin. The active (CYP21A2) and pseudogene (CYP21A1P) alleles were screened for the presence of the new variations in controls.

RESULTS

Two novel missense mutations, F404S in exon 9 and T450P in exon 10, were found in homozygous forms in two female patients with a salt-wasting (SW) phenotype. These novel variants were screened by allele-specific polymerase chain reaction (PCR) and excluded in 100 unrelated normal alleles. Prediction of clinical severity, based on molecular modelling and sequence conservation, correlates well with the clinical diagnosis of the patients carrying these mutations. The third novel mutation, a small 10-bp deletion in exon 1, g.19_28del, was found in a female patient with a simple virilizing phenotype in a compound heterozygous form with the common intron 2 splice mutation (IVS2-13A/C>G). This frameshift mutation causes a premature stop codon at amino acid position 48, L48X, resulting in a nonfunctional protein. The CYP21A1P pseudogene alleles were also screened and none of these novel mutations could be detected.

CONCLUSIONS

Three novel mutations were found in the CYP21A2 gene and predicted to drastically impair enzyme activity resulting in severe classic CAH. None of these mutations occurs in the CYP21A1P pseudogene.

Characterization of novel missense mutations in CYP21 causing congenital adrenal hyperplasia

Congenital adrenal hyperplasia due to 21-hydroxylase deficiency is the most common inherited disorder of steroid metabolism, with an incidence of 1/10,000 in the general Caucasian population. Although most patients carry a deletion of the CYP21 gene or any of nine pseudogene-derived point mutations, the number of reported rare mutations continues to increase, and consist today of more than 80 different point mutations. In this study, we report the characterization of four additional missense mutations in CYP21. Two of these, L166P and A391T, are novel missense mutations, whereas the R479L and R483Q mutations have been detected previously. Functional assays of mutagenized CYP21 were performed in transiently transfected mammalian cells in vitro, and enzymatic ability of substrate conversion of the two natural substrates of CYP21-17-hydroxyprogesterone and progesterone-was determined. All mutants displayed reduced in vitro enzyme activities compared with wild type, but to different extents, corresponding to clinical phenotypes that span the whole spectrum of disease severity. Functional studies are important to further establish the relationships between genotype and clinical phenotype as well as in vitro CYP21 activity in congenital adrenal hyperplasia due to 21-hydroxylase deficiency. This has relevance for diagnosis, prognosis, and genetic counseling for affected families.

Molecular model of human CYP21 based on mammalian CYP2C5: structural features correlate with clinical severity of mutations causing congenital adrenal hyperplasia

Enhanced understanding of structure-function relationships of human 21-hydroxylase, CYP21, is required to better understand the molecular causes of congenital adrenal hyperplasia. To this end, a structural model of human CYP21 was calculated based on the crystal structure of rabbit CYP2C5. All but two known allelic variants of missense type, a total of 60 disease-causing mutations and six normal variants, were analyzed using this model. A structural explanation for the corresponding phenotype was found for all but two mutants for which available clinical data are also discrepant with in vitro enzyme activity. Calculations of protein stability of modeled mutants were found to correlate inversely with the corresponding clinical severity. Putative structurally important residues were identified to be involved in heme and substrate binding, redox partner interaction, and enzyme catalysis using docking calculations and analysis of structurally determined homologous cytochrome P450s (CYPs). Functional and structural consequences of seven novel mutations, V139E, C147R, R233G, T295N, L308F, R366C, and M473I, detected in Scandinavian patients with suspected congenital adrenal hyperplasia of different severity, were predicted using molecular modeling. Structural features deduced from the models are in good correlation with clinical severity of CYP21 mutants, which shows the applicability of a modeling approach in assessment of new CYP21 mutations.

Functional studies of two novel and two rare mutations in the 21-hydroxylase gene

Congenital adrenal hyperplasia (CAH) is most commonly due to 21-hydroxylase deficiency and presents with a wide spectrum of clinical manifestations, from prenatal virilization and salt-wasting in the neonatal period to precocious pubarche and late-onset hyperandrogenic symptoms during adulthood. A limited number of mutations account for the majority of all mutated alleles, but a growing number of rare mutations are responsible for the disease in some patients. By sequence analysis of the CYP21A2 gene, we identified two novel (I171N and L446P) and two rare (R341P and R426H) mutations in seven Italian patients with CAH. One of the patients was diagnosed with mild non-classical CAH and was found to be a compound heterozygote (I171N/V281L), while all other patients showed severe phenotypes with latent or manifest salt-wasting. The residual activities measured after expression of the four mutant enzymes in COS-1 cells were all below 1% towards both natural substrates (17-OH-progesterone and progesterone) compared with the wild-type protein. All four mutations are, thus, associated with severe enzyme deficiency and are predicted to cause classic CAH if found in trans with other mutations causing severe enzyme deficiency.

Linkage between I172N mutation, a marker of 21-hydroxylase deficiency, and a single nucleotide polymorphism in Int6 of CYP21B gene: A genetic study of Sardinian family

Congenital adrenal hyperplasia (CAH) is a genetic disorder due to 21-hydroxylase deficiency. More than 90% of CAH cases are caused by mutations of CYP21B gene, most of which are the result of microconversion events between the functional gene and its pseudogene. Using a combination of RFLP and direct sequencing analysis, in this paper we describe the genetic study of a Sardinian family carrying I172N mutation in linkage with a SNP namely 1636 Int6. The characterization of new polymorphisms in CYP21B can improve the analysis of segregation of CYP21B mutated alleles especially in genetic familial studies. The analysis of linkage between specific mutations and this SNPs, especially if focused on genetic familial studies, may improve the quality of genetic analysis of 21-hydroxylase deficiency.

An update of congenital adrenal hyperplasia

Congenital adrenal hyperplasia (CAH) is a family of autosomal recessive disorders caused by mutations that encode for enzymes involved in one of the various steps of adrenal steroid synthesis. These defects result in the absence or the decreased synthesis of cortisol from its cholesterol precursor. The anterior pituitary secretes excess adrenocorticotrophic hormone (ACTH) via feedback regulation by cortisol, which results in overstimulation of the adrenals and causes hyperplasia. Symptoms due to CAH can vary from mild to severe depending on the degree of ensymatic defect. In the classical form of CAH, there is a severe enzymatic defect owing to mutations in the CYP21 gene. Classically affected female fetuses undergo virilization of the genitalia prenatally and present with genital ambiguity at birth; however, prenatal treatment of CAH with dexamethasone to prevent ambiguity has been successfully utilized for over a decade. In the less severe, late-onset form of CAH, prenatal virilization does not occur. The milder enzyme deficiency was termed nonclassical 21-hydroxylase deficiency (NC21OHD) in 1979 and was later found to be the most common autosomal recessive disorder in humans. Disease frequency of NC21OHD varies between ethnic groups with the highest ethnic-specific disease frequency in Ashkenazi Jews at 1/27. NC21OHD is diagnosed by serum elevations of 17-OHP that plot on a nomogram between the range for unaffected individuals and levels observed for classical CAH and is typically confirmed with molecular genetic analysis. Similar to classical CAH, nonclassical 21-hydroxylase deficiency may cause premature development of pubic hair, advanced bone age, accelerated linear growth velocity and diminished final height in both males and females. Severe cystic acne has also been attributed to nonclassical CAH. Women may present with symptoms of androgen excess, including hirsutism, temporal baldness, and infertility. Menarche in females may be normal or delayed and secondary amenorrhea is a frequent occurrence. Polycystic ovary syndrome may also be seen in these patients. In males, early beard growth, acne, and growth spurt may prompt the diagnosis of NC21OHD. Although many males appear to be asymptomatic, they may present with oligozoospermia or diminished fertility. Individuals presenting to dermatology and infertility clinics with symptoms of hyperandrogenemia are rarely screened for NC21OHD. However, with hormonal and molecular genetic screening, previously undiagnosed patients may be identified and can therefore receive glucocorticoid treatment, which has been shown to reverse symptoms within 3 months.

Validation and clinical application of a locus-specific polymerase chain reaction- and minisequencing-based assay for congenital adrenal hyperplasia (21-hydroxylase deficiency)

Congenital adrenal hyperplasia is an autosomal recessive disorder caused by defective adrenal steroid biosynthesis, resulting in reduced glucocorticoid and increased androgen production. The majority of cases are due to inactivation of the 21-hydroxylase gene (CYP21A2), most commonly caused by genomic rearrangements with the adjacent, highly homologous pseudogene CYP21A. The most common deletions and gene conversion events have been defined and are typically detected by Southern hybridization detection of CYP21 rearrangements and/or polymerase chain reaction (PCR). However, Southern hybridization is laborious, and allele-specific PCR results may be difficult to interpret. We have therefore developed a locus-specific, PCR-based, minisequencing method for detecting the 12 most common CYP21A2 mutations. We validated the assay using a panel of 20 previously genotyped samples obtained from individuals who collectively have a broad spectrum of mutations causing 21-hydroxylase deficiency. We also used 19 control samples having no CYP21 mutations. All validation samples were correctly typed, and we identified haplotypes that may be useful for clinical diagnosis. Results from 102 clinical samples demonstrate that this assay is a rapid, reliable, and robust method for locus-specific identification of mutations and is suitable for routine clinical use and prenatal diagnosis.

Phenotype and genotype correlation of the microconversion from the CYP21A1P to the CYP21A2 gene in congenital adrenal hyperplasia

Deficiency of 21-hydroxylase is the most common form of congenital adrenal hyperplasia (CAH-21OH). We determined by allele-specific PCR the frequency of microconversion in the CYP21A2 gene in 50 Brazilian patients with the classical (salt wasting: SW and simple virilizing: SV) forms and nonclassical (NC) form of CAH-21OH and correlated genotype with phenotype. Genotypes were classified into three mutation groups (A, B, and C) based on the amount of enzymatic activity in in vitro studies using adrenal cells. In 94 unrelated alleles, we diagnosed 76% of the affected alleles after screening for 7 microconversions. The most frequent point mutations observed in this series were I172N (19%), V281L (18%), and IVS2,A/C>G,-12 (15%). In the SW form, the most frequent mutation was IVS2,A/C>G,-12 (38%), in the SV form it was I172N (53%), and in the NC form it was V281L (57.7%). We observed a good correlation between genotype and phenotype. Discordance between genotype and phenotype was found in one SV patient with a mild mutation in one of the alleles (R356W/V281L). However, we cannot rule out the presence of an additional mutation in these alleles. We also observed a good correlation of genotype with 17alpha-hydroxyprogesterone, testosterone, and androstenedione levels. The severity of external genitalia virilization correlated with the severity of mutation. In conclusion, the frequencies described in the present study did not differ from worldwide studies, including the Brazilian population. The few differences observed may reflect individual sample variations. This new Brazilian cohort study suggests the presence of new mutations in Brazilian patients with different forms of CAH-21OH.