Genotype-phenotype correlation in 1,507 families with congenital adrenal hyperplasia owing to 21-hydroxylase deficiency. Proc Natl Acad Sci U S A. 2013;110:2611-2616. [PMID: 23359698 DOI: 10.1073/pnas.1300057110]

Improved Genetic Characterization of Congenital Adrenal Hyperplasia by Long-Read Sequencing Compared with Multiplex Ligation-Dependent Probe Amplification Plus Sanger Sequencing

Genetic analysis of congenital adrenal hyperplasia (CAH) has been challenging because of high homology between CYP21A2 and its pseudogene CYP21A1P. This study aimed to evaluate the clinical utility of long-read sequencing (LRS) in diagnosis of CAH attributable to 21-hydroxylase deficiency by comparing with multiplex ligation-dependent probe amplification plus Sanger sequencing. In this retrospective study, 69 samples, including 49 probands from 47 families with high-risk of CAH, were enrolled and blindly subjected to detection of CAH by LRS. The genotype results were compared with control methods, and discordant samples were validated by additional Sanger sequencing. LRS successfully identified biallelic variants of CYP21A2 in the 39 probands diagnosed as having CAH. The remaining 10 probands were not patients with CAH. Additionally, LRS directly identified two pathogenic single-nucleotide variations (SNVs; c.293-13C/A>G and c.955C>T) in the presence of interference caused by nearby insertions/deletions (indels). The cis-trans configuration of two or more SNVs and indels identified in 18 samples was directly determined by LRS without family analysis. Eight CYP21A1P/A2 or TNXA/B deletion chimeras, composed of five subtypes, were identified; and the junction sites were precisely determined. Moreover, LRS determined the exact genotype in two probands who had three heterozygous SNVs/indels and duplication, which could not be clarified by control methods. These findings highlight that LRS could assist in more accurate genotype imputation and more precise CAH diagnosis.

Current Advances in the Management of Congenital Adrenal Hyperplasia

Congenital adrenal hyperplasia (CAH) is an autosomal recessive genetic condition caused by various enzyme deficiencies that result in disruptions of pathways of adrenal steroidogenesis. 21-hydroxylase deficiency is the most common form of CAH and has a variable phenotype which ranges a spectrum, from the most severe salt-wasting type to the simple-virilizing type and the least severe nonclassical form. Patients with CAH are at risk for various comorbidities due to the underlying adrenal hormone production imbalance as well as the treatment of the condition, which typically includes supraphysiologic glucocorticoid dosing. Children and adults require frequent monitoring and careful medication dosing adjustment. However, there are multiple novel therapies on the horizon that offer promise to patients with CAH in optimizing their treatment regimens and reducing the risk of comorbidities.

Expanded targeted preconception screening panel in Israel: findings and insights

BACKGROUND

We aimed to analyse the efficacy and added value of a targeted Israeli expanded carrier screening panel (IL-ECSP), beyond the first-tier test covered by the Israeli Ministry of Health (IMOH) and the second-tier covered by the Health Maintenance Organisations (HMOs).

METHODS

A curated variant-based IL-ECSP, tailored to the uniquely diverse Israeli population, was offered at two tertiary hospitals and a major genetics laboratory. The panel includes 1487 variants in 357 autosomal recessive and X-linked genes.

RESULTS

We analysed 10 115 Israeli samples during an 18-month period. Of these, 6036 (59.7%) were tested as couples and 4079 (40.3%) were singles. Carriers were most frequently identified with mutations in the following genes: GJB2/GJB6 (1:22 allele frequency), CFTR (1:28), GBA (1:34), TYR (1:39), PAH (1:50), SMN1 (1:52) and HEXA (1:56). Of 3018 couples tested, 753 (25%) had no findings, in 1464 (48.5%) only one partner was a carrier, and in 733 (24.3%) both were carriers of different diseases. We identified 79 (2.6%) at-risk couples, where both partners are carriers of the same autosomal recessive condition, or the female carries an X-linked disease. Importantly, 48.1% of these would not have been detected by ethnically-based screening tests currently provided by the IMOH and HMOs, for example, variants in GBA, TYR, PAH and GJB2/GJB6.

CONCLUSION

This is the largest cohort of targeted ECSP testing, tailored to the diverse Israeli population. The IL-ECSP expands the identification of couples at risk and empowers their reproductive choices. We recommend endorsing an expanded targeted panel to the National Genetic Carrier Screening programme.

High carrier frequency of CYP21A2 gene mutations in Southern India - underscoring the need for genetic testing in Congenital Adrenal Hyperplasia

PURPOSE

Congenital Adrenal Hyperplasia (CAH) is one of the highly prevalent autosomal recessive endocrine disorders. The majority of CAH cases result from mutations in the CYP21A2 gene, leading to 21-hydroxylase deficiency. However, with the pseudogene-associated challenges in CYP21A2 gene analysis, routine genetic diagnostics and carrier screening in CAH are not a part of the first-tier investigations in a clinical setting. Furthermore, there is a lack of data on the carrier frequency for 21-OH deficiency. Therefore, this study is aimed at investigating the carrier frequency of common pseudogene derived CYP21A2 mutations in Southern India.

METHODS

Recently, a cost-effective Allele-specific PCR based genotyping for CYP21A2 hotspot mutations has been demonstrated to be a highly specific and sensitive assay at the authors' center. Leveraging this approach, a total of 1034 healthy individuals from South India underwent screening to identify the carrier frequency of nine hotspot mutations in the CYP21A2 gene.

RESULTS

In this study, it was observed that 9.76% of the subjects were carriers for one or more of the nine different CYP21A2 mutations. Among the carriers, the most common was the large 30 kb deletion, followed by II72N, E6 CLUS, and I2G mutations.

CONCLUSION

We have identified a high prevalence of CYP21A2 mutation carriers in Southern India. These findings emphasize the importance of implementing and expanding cost-effective genetic diagnostics and carrier screening throughout India. Such initiatives would play a crucial role in managing the disease burden, enabling early intervention, and establishing guidelines for CAH newborn genetic screening in the country. This study represents the first carrier screening data on CYP21A2 hotspot mutations from India and is the largest study conducted till date in this context.

Compendium of Metabolomic and Genomic Datasets for Cyanobacteria: Mined the Gap

Cyanobacterial blooms, producing toxic secondary metabolites, are becoming increasingly common phenomena in the face of rising global temperatures. They are the world's most abundant photosynthetic organisms, largely owing their success to a range of highly diverse and complex natural products possessing a broad spectrum of different bioactivities. Over 2600 compounds have been isolated from cyanobacteria thus far, and their characterisation has revealed unusual and useful chemistries and motifs including alkynes, halogens, and non-canonical amino acids. Genome sequencing of cyanobacteria lags behind natural product isolation, with only 19% of cyanobacterial natural products associated with a sequenced organism. Recent advances in meta(genomics) provide promise to narrow this gap and has also facilitated the uprise of combined genomic and metabolomic approaches, heralding a new era of discovery of novel compounds. Analyses of the datasets described within this manuscript reveal the asynchrony of current genomic and metabolomic data, highlight the chemical diversity of cyanobacterial natural products. Linked to this manuscript, we make these manually curated datasets freely accessible for the public to facilitate further research in this important area.

Challenging Molecular Diagnosis of Congenital Adrenal Hyperplasia (CAH) Due to 21-Hydroxylase Deficiency: Case Series and Novel Variants of CYP21A2 Gene

Congenital adrenal hyperplasia (CAH) is a group of autosomal recessive genetic defects in cortisol synthesis and shows elevated ACTH concentrations, which in turn has downstream effects. The most common variant of CAH, 21-hydroxylase deficiency (21OHD), is the result of pathogenic variants in the CYP21A2 gene and is one of the most common monogenic disorders. However, the genetics of 21OHD is complex and challenging. The CYP21A2 gene is located in the RCCX copy number variation (CNV), a complex, multiallelic, and tandem CNV in the major histocompatibility complex (MHC) class III region on chromosome 6 (band 6p21.3). Here, CYP21A2 and its pseudogene CYP21A1P are located 30 kb apart and share a high nucleotide homology of approximately 98% and 96% in exons and introns, respectively. This high-sequence homology facilitates large structural rearrangements, copy number changes, and gene conversion through intergenic recombination. There is a good genotype-phenotype correlation in 21OHD, and genotyping can be performed to confirm the clinical diagnosis, predict long-term outcomes, and determine genetic counseling. Thus, genotyping in CAH is clinically relevant but the interpretations can be challenging for non-initiated clinicians. Here, there are some concrete examples of how molecular diagnosis can sometimes require the use of multiple molecular strategies.

Genetic diagnosis of endocrine disorders in Cyprus through the Cyprus Institute of Neurology and Genetics: an ENDO-ERN Reference Center

The report covers the current and past activities of the department Molecular Genetics-Function and Therapy (MGFT) at the Cyprus Institute of Neurology and Genetics (CING), an affiliated Reference Center for the European Reference Network on Rare Endocrine Conditions (Endo-ERN).The presented data is the outcome of > 15 years long standing collaboration between MGFT and endocrine specialists from the local government hospitals and the private sector. Up-to-date > 2000 genetic tests have been performed for the diagnosis of inherited rare endocrine disorders. The major clinical entities included Congenital Adrenal Hyperplasia (CAH) due to pathogenic variants in CYP21A2 gene and Multiple Endocrine Neoplasia (MEN) type 2 due to pathogenic variants in the RET proto-oncogene. Other rare and novel pathogenic variants in ANOS1, WDR11, FGFR1, RNF216, and CHD7 genes were also found in patients with Congenital Hypogonadotropic Hypogonadism. Interestingly, a few patients with Disorders of Sexual Differentiation (DSD) shared rare pathogenic variants in the SRD5A2, HSD17B3 and HSD3B2 while patients with Glucose and Insulin Homeostasis carried theirs in GCK and HNF1A genes. Lastly, MGFT over the last few years has established an esteemed diagnostic and research program on premature puberty with emphasis on the implication of MKRN3 gene on the onset of the disease and the identification of other prognosis biomarkers.As an Endo-ERN member MGFT department belongs to this large European network and holds the same humanistic ideals which aim toward the improvements of health care for patients with rare endocrine conditions in respect to improved and faster diagnosis.

Targeted long-read sequencing for comprehensive detection of CYP21A2 mutations in patients with 21-hydroxylase deficiency

BACKGROUND

21-Hydroxylase deficiency (21-OHD) is caused by pathogenic CYP21A2 variations. CYP21A2 is arranged in tandem with its highly homologous pseudogene CYP21A1P; therefore, it is prone to mismatch and rearrangement, producing different types of complex variations. There were few reports on using only one method to detect different CYP21A2 variants simultaneously.

AIMS

Targeted long-read sequencing method was used to detect all types of CYP21A2 variants in a series of patients with 21-OHD.

METHODS

A total of 59 patients with 21-OHD were enrolled from Peking Union Medical College Hospital. Long-range locus-specific PCR and long-read sequencing (LRS) were performed to detect the pathogenic variants in CYP21A2.

RESULTS

Copy-number variants of CYP21A2 were found in 25.4% of patients, including 5.1% with 3 copies of CYP21A2, 16.9% with 1 copy of CYP21A2, and 3.4% with 0 copy of CYP21A2. The remaining 74.6% of patients had 2 copies of CYP21A2. Pathogenic variants were identified in all 121 alleles of 59 patients. Specifically, single-nucleotide variants and small insertions/deletions (< 50 bp) were detected in 79 alleles, of which conversed from CYP21A1P were detected in 63 alleles, and rare variants were found in the other 16 alleles. Large gene conversions (> 50 bp) from pseudogene were detected in 10 alleles, and different chimeric genes (CYP21A1P/CYP21A2 or TNXA/TNXB) formed by large deletions were detected in 32 alleles. Of all variants, p.I173N was the most common variant (19.0%).

CONCLUSIONS

Our study demonstrated that targeted long-read sequencing is a comprehensive method for detecting CYP21A2 variations, which is helpful for genetic diagnosis in 21-OHD patients.

Congenital Adrenal Hyperplasia - A Comprehensive Review of Genetic Studies on 21-Hydroxylase Deficiency from India

Congenital adrenal hyperplasia (CAH) comprises a heterogeneous group of autosomal recessive disorders impairing adrenal steroidogenesis. Most cases are caused by mutations in the CYP21A2 gene resulting in 21-hydroxylase (21-OH) deficiency (21-OHD). The genetics of 21-OH CAH is complexed by a highly homologous pseudogene CYP21A1P imposing several limitations in the molecular analysis. Therefore, genetic testing is still not a part of routine CAH diagnosis and is mainly dependent on 17-hydroxy progesterone (OHP) measurements. There are very few reports of CYP21A2 gene analysis from India and there is no comprehensive review available on genetic testing and the spectrum of CYP21A2 mutations from the country. This review focuses on the molecular aspects of 21-OHD and the genetic studies on CYP21A2 gene reported from India. The results of these studies insist the compelling need for large-scale CYP21A2 genetic testing and newborn screening (NBS) in India. With a high disease prevalence and consanguinity rates, robust and cost-effective genetic testing for 21-OH CAH would enable an accurate diagnosis in routine clinical practice. Whereas establishing affordable genotyping assays even in secondary care or resource-poor settings of the country can identify 90% of the mutations that are pseudogene derived, initiatives on reference laboratories for CAH across the nation with comprehensive genetic testing facilities will be beneficial in those requiring extended analysis of CYP21A2 gene. Further to this, incorporating genetic testing in NBS and carrier screening programmes will enable early diagnosis, better risk assessment and community-based management.

Genotype-Specific Cortisol Reserve in a Cohort of Subjects With Nonclassic Congenital Adrenal Hyperplasia (NCCAH)

CONTEXT

Recent guidelines suggest that patients with nonclassic congenital adrenal hyperplasia (NCCAH) stop glucocorticoid therapy after achieving adult height. However, these guidelines do not differentiate between NCCAH genotype groups.

OBJECTIVE

Compare ACTH-stimulated cortisol and 17-hydroxyprogesterone (17OHP) levels, and the rate of partial cortisol insufficiency in subjects with NCCAH carrying one mild and one severe (mild/severe) mutation vs subjects with biallelic mild (mild/mild) mutations.

METHODS

Retrospective evaluation of the medical records of 122 patients who presented with postnatal virilization and were diagnosed with NCCAH. Patients underwent standard intravenous 0.25 mg/m2 ACTH stimulation testing. Those with stimulated 17OHP level ≥40 nmol/L were screened for the 9 most frequent CYP21A2 gene mutations followed by multiplex ligation-dependent probe amplification. A stimulated cortisol level below 500 nmol/L was defined as partial cortisol deficiency.

RESULTS

Patients were subdivided into 3 genotype groups: 77 carried the mild/mild genotype, mainly homozygous for p.V281L mutation; 29 were compound heterozygous for mild/severe mutation, mainly p.V281L/p.I2Splice, and 16 were heterozygous for p.V281L, and were excluded from statistical evaluation. Stimulated cortisol levels were significantly lower in the mild/severe than in the mild/mild group (mean ± SD, 480 ± 90 vs 570 ± 125 nmol/L, P < .001). The mild/severe group exhibited a significantly higher rate of partial cortisol insufficiency (21/28, 75% vs 28/71, 39%, P = .004). Peak 17OHP was significantly higher in the mild/severe group (198 ± 92 vs 118 ± 50 nmol/L, P < .001).

CONCLUSION

The high rate of partial adrenal insufficiency in the mild/severe group underscores the need to carefully consider the value of glucocorticoid therapy cessation and the importance of stress coverage in this group.

A MinION-based Long-Read Sequencing Application With One-Step PCR for the Genetic Diagnosis of 21-Hydroxylase Deficiency

CONTEXT

Recently developed long-read sequencing (LRS) technology has been considered an option for CYP21A2 analysis. However, the clinical use of LRS for CYP21A2 analysis is limited.

OBJECTIVE

This study's objective is to develop an efficient and low-cost LRS system for CYP21A2 screening.

METHODS

A DNA fragment library was prepared in a single polymerase chain reaction (PCR) that covers the entire CYP21A2 gene and all known junctions caused by TNXB gene structural rearrangements, yielding a single 8-kb product of CYP21A2 or CYP21A1P/CYP21A2 chimera. After barcoding, the PCR products were sequenced on a MinION-based platform with Flongle Flow Cell R9.4.1 and R10.4.1.

RESULTS

The reference genotypes of 55 patients with 21-hydroxylase deficiency (21OHD) were established using the conventional method with multiplex ligation-dependent probe amplification (MLPA) and nested PCR. LRS using Flongle Flow Cell R9.4.1 yielded consistent results. Additionally, the recently updated LRS "duplex" analysis with Flongle flow cell R10.4.1 was tested to reveal an advantage of accurately sequencing a variant located on the homopolymer region. By introducing a barcode system, the cost was reduced to be comparable to that of conventional analysis. A novel single-nucleotide variation was discovered at the acceptor site of intron 7, c.940-1G > C. We also identified a subtype of the classical chimeric junction CH2, "CH2a," in the region from the latter part of intron 5 to exon 6.

CONCLUSION

We successfully established a novel low-cost and highly accurate LRS system for 21OHD genetic analysis. Our study provides insight into the feasibility of LRS for diagnosing 21OHD and other genetic diseases caused by structural rearrangements.

Characterization of the CYP21A2 Gene Mutations in Children with Classic Congenital Adrenal Hyperplasia

OBJECTIVE

To characterize the CYP21A2 gene mutations in children with classic congenital adrenal hyperplasia (CAH).

METHODS

A prospective, cross-sectional study was conducted on 24 children with classic CAH. Molecular characterization of the CYP21A2 gene was carried out by Sanger sequencing, multiplex ligation-dependent probe amplification (MLPA), or clinical exome sequencing. Another 21 previously mutation-proven CAH patients were also included and a combined result was drawn.

RESULTS

Out of 45 children, pathogenic variants in the CYP21A2 gene were identified in 43 patients (95.5%). Homozygous, probable compound heterozygous, and heterozygous variants were seen in 69%, 22%, and 18% of patients, respectively. The most common variant was c.293-13C/A>G (33%), followed by deletion/duplication (24%), and c.955C>T (p.Gln319Ter) (21%), similar to previous Indian studies. Allelic frequencies of c.332_339del and c.518 T>A (p.Ile173Asn) were 9% and 4%, respectively. Less common variants were c.923dupT (p.Leu308PhefsTer6), c.92C>T (p.Pro31Leu), c.1069C>T (p.Arg357Trp), c.1267G>C (p.Gly423Arg), and c.710_719delins (p.Ile237_Met240delinsAsnGluGluLys). A good genotype-phenotype correlation was observed; only p.Pro31Leu and p.Ile173Asn variants showed discordance. The diagnostic yield of Sanger sequencing alone, Sanger sequencing with MLPA, and clinical exome alone was 85%, 100%, and 100%, respectively.

CONCLUSIONS

All children, except two, diagnosed clinically as classic CAH, showed pathogenic variants in the CYP21A2 gene; the most common variant was c.293-13 C/A>G. The results suggest a broad mutation spectrum in the authors' single-center cohort of children with CAH. Clinical exome sequencing is the preferred stand-alone method for molecular diagnosis of CAH.

Genotyping in patients with congenital adrenal hyperplasia by sequencing of newborn bloodspot samples

OBJECTIVES

Genotype-phenotype correlation in congenital adrenal hyperplasia (CAH) caused by 21-hydroxylase deficiency ranges from 45 to 97 %. We performed massively parallel sequencing of CYP21A2 on stored newborn bloodspot samples to catalogue the genotypes present in our patients with CAH and enable genotype-phenotype comparison.

METHODS

Participants ≤15 years old with clinically diagnosed CAH were recruited from The Sydney Children's Hospitals Network. Phenotype was classified from clinical and biochemical details in the medical record as salt wasting (SW), simple virilising (SV), non-classic (NC) or an intermediate phenotype (SW/SV; SV/NC). Amplicon-based sequencing for CYP21A2 was performed on stored newborn bloodspot samples by the New South Wales Newborn Bloodspot Screening Laboratory on MiSeq™Dx (Illumina, California). Available genetic test results were also obtained from the medical records.

RESULTS

Samples from 67 participants (43 % female, age 0.3-15 years) were sequenced, including 9 sibships. SW phenotype was present in 33/67 participants (49 %), SV in 9 (13 %) and NC in 16 (24 %). Intermediate phenotypes included SW/SV in seven participants (10 %) and SV/NC in two (3 %). Variants were identified in 90/116 alleles (78 %). A complete genotype was available in 47/67 participants (70 %). The most common genotype was homozygous c.293-13A/C>G (I2G) in 7/47 participants (15 %). Genotype correlated with the most commonly reported phenotype in 36/44 cases (82 %). Correlation was higher in SW and NC phenotypes.

CONCLUSIONS

This study uses genetic testing of newborn bloodspots to identify and characterise the genotypes present in an ethnically diverse Australian population with CAH. It further strengthens our knowledge of genotype-phenotype correlations in CAH.

Hormonal control during infancy and testicular adrenal rest tumor development in males with congenital adrenal hyperplasia: a retrospective multicenter cohort study

IMPORTANCE

Testicular adrenal rest tumors (TARTs), often found in male patients with congenital adrenal hyperplasia (CAH), are benign lesions causing testicular damage and infertility. We hypothesize that chronically elevated adrenocorticotropic hormone exposure during early life may promote TART development.

OBJECTIVE

This study aimed to examine the association between commencing adequate glucocorticoid treatment early after birth and TART development.

DESIGN AND PARTICIPANTS

This retrospective multicenter (n = 22) open cohort study collected longitudinal clinical and biochemical data of the first 4 years of life using the I-CAH registry and included 188 male patients (median age 13 years; interquartile range: 10-17) with 21-hydroxylase deficiency (n = 181) or 11-hydroxylase deficiency (n = 7). All patients underwent at least 1 testicular ultrasound.

RESULTS

TART was detected in 72 (38%) of the patients. Prevalence varied between centers. When adjusted for CAH phenotype, a delayed CAH diagnosis of >1 year, compared with a diagnosis within 1 month of life, was associated with a 2.6 times higher risk of TART diagnosis. TART onset was not predicted by biochemical disease control or bone age advancement in the first 4 years of life, but increased height standard deviation scores at the end of the 4-year study period were associated with a 27% higher risk of TART diagnosis.

CONCLUSIONS AND RELEVANCE

A delayed CAH diagnosis of >1 year vs CAH diagnosis within 1 month after birth was associated with a higher risk of TART development, which may be attributed to poor disease control in early life.

Lessons Learned from 17 Years of Multidisciplinary Care for Differences of Sex Development Patients at a Single Indonesian Center

BACKGROUND

Our multidisciplinary team (MDT) is a large specialized team based in Semarang, Indonesia, that cares for a wide variety of pediatric and adult individuals with differences of sex development (DSD) from across Indonesia. Here, we describe our work over the last 17 years.

METHODS

We analyzed phenotypic, hormonal, and genetic findings from clinical records for all patients referred to our MDT during the period 2004-2020.

RESULTS

Among 1,184 DSD patients, 10% had sex chromosome DSD, 67% had 46,XY DSD, and 23% had 46,XX DSD. The most common sex chromosome anomaly was Turner syndrome (45,X) (55 cases). For patients with 46,XY DSD under-masculinization was the most common diagnosis (311 cases), and for 46,XX DSD, a defect of Müllerian development was most common (131 cases) followed by congenital adrenal hyperplasia (CAH) (116 cases). Sanger sequencing, MLPA, and targeted gene sequencing of 257 patients with 46,XY DSD found likely causative variants in 21% (55 cases), with 13 diagnostic genes implicated. The most affected gene codes for the androgen receptor. Molecular analysis identified a diagnosis for 69 of 116 patients with CAH, with 62 carrying variants in CYP21A2 including four novel variants, and 7 patients carrying variants in CYP11B1. In many cases, these genetic diagnoses influenced the clinical management of patients and their families.

CONCLUSIONS

Our work has highlighted the occurrence of different DSDs in Indonesia. By applying sequencing technologies as part of our clinical care, we have delivered a number of genetic diagnoses and identified novel pathogenic variants in some genes, which may be clinically specific to Indonesia. Genetics can inform many aspects of DSD clinical management, and while many of our patients remain undiagnosed, we hope that future testing may provide answers for even more.

Clinical analysis of 78 patients with nonclassical 21-hydroxylase deficiency

PURPOSE

Retrospectively analyze the clinical characteristics of patients with nonclassical 21-hydroxylase deficiency (NC21OHD) as well as the relationship between the gene mutations and endocrine hormones. In addition, the relationship between different basal 17-hydroxyprogesterone (17OHP) levels and patients' glucolipid metabolism, hormone levels, pregnancy, and treatment outcomes were examined.

METHODS

Clinical data of 78 females with NC21OHD from January 2012 to July 2022 in the Department of Endocrinology and Metabolism of the Third Affiliated Hospital of Guangzhou Medical University were retrospectively analyzed. Diagnosis was based on the 17OHP level combined with clinical manifestations, imaging, and other endocrine hormones and the cytochrome P450 c21, steroid 21-hydroxylase (CYP21A2) gene.

RESULTS

The age at diagnosis of the 78 patients was 29.1 ± 4.2 years; 83.3% (65/78) of the patients had menstrual abnormalities, 70 patients were of childbearing age, and 97.1% (68/70) had a history of infertility with a median time of infertility of 3.6 years. Moreover, 71.8% (56/78) of the patients had polycystic ovaries, 26.9% (21/78) had hyperandrogenemia manifestations on physical examination, 66.7% (52/78) had adrenal hyperplasia, 32.1% (25/78) had combined dyslipidemia, and 41.0% (32/78) had combined insulin resistance. Pathogenic mutations were detected in 78.2% (61/78) of the patients with both CYP21A2 alleles; 14.1% (11/78) of the patients had only one allele and 7.7% (6/78) had no pathogenic mutations. The levels of total testosterone (TT), progesterone (P) (0 min, 30 min), and 17-OHP (0 min, 30 min, 60 min) in the adrenocorticotropic hormone (ACTH) stimulation test varied between the groups. Furthermore, patients with NC21OHD were divided into 17OHP < 2 ng/ml, 2 ng/ml < 17OHP < 10 ng/ml, and 17OHP ≥ 10 ng/ml groups according to their different basal 17OHP levels. The 17OHP ≥ 10 ng/ml group had significantly higher TT, FT4, basal and post-stimulation progesterone, and 17OHP, net value added of 17-hydroxyprogesterone (△17OHP), net value added of 17-hydroxyprogesterone/net value added of cortisol ratio (△17OHP/△F), the incidence of adrenal hyperplasia, and number of gene mutations compared to those of the 17OHP < 2 ng/ml group (P < 0.05). NC21OHD infertile patients who received low-dose glucocorticoids showed a significant increase in pregnancy and live birth rates, and a significant decrease in miscarriage rate (all P < 0.05).

CONCLUSION

Comprehensive analysis is important as NCCAH diagnoses may be false positive or false negative based on clinical characteristics, hormone levels, and gene detection. Females with NC21OHD showed varying degrees of fertility decline; thus, low doses of glucocorticoid treatment for infertile females with NC21OHD can improve fertility and fertility outcomes.

Natural Algaecide Sphingosines Identified in Hybrid Straw Decomposition Driven by White-Rot Fungi

Harmful algal blooms (HABs), which are promoted by eutrophication and intensified by global warming, occur worldwide. Allelochemicals, which are natural chemicals derived from plants or microbes, are emerging weapons to eliminate these blooms. However, the cost and technical challenges have limited the discovery of novel antialgal allelochemicals. Herein, the decomposition of agricultural straws is manipulated by white-rot fungi and achieved elevated antialgal efficiency. The transcriptomic analysis reveals that nutrient limitation activated fungal decomposition. By using a comparative nontarget metabolomics approach, a new type of allelochemical sphingosines (including sphinganine, phytosphingosine, sphingosine, and N-acetylsphingosine) is identified. These novel natural algaecides exhibit superior antialgal capability, with as high as an order of magnitude lower effective concentration on blooming species than other prevalent allelochemicals. The co-expression relationship between transcriptomic and metabolomic results indicate that sphinganine is strongly correlated with the differentially expressed lignocellulose degradation unigenes. The algal growth suppression is triggered by the activation of programmed cell death, malfunction of algal photosystem and antioxidant system, the disruption on CO2 assimilation and light absorption. The sphingosines reported here are a new category of allelochemicals in addition to the well-known antialgal natural chemicals, which are potential species-specific agents for HABs control identified by multi-omics methodology.

Genetic Characterization of a Cohort of Italian Patients with Congenital Adrenal Hyperplasia Due to 21-Hydroxylase Deficiency

INTRODUCTION

Defects in the steroid 21-hydroxylase gene (CYP21A2) cause 21-hydroxylase deficiency (21OHD), the main cause of congenital adrenal hyperplasia (CAH). The disease shows a broad spectrum of clinical forms, ranging from severe or classical (salt wasting, SW, and simple virilizing, SV), to mild late onset or nonclassical (NC). 21OHD affects 1 in 15,000 in its severe classic form and 1 in 200-1000 in its mild NC form. There are many studies reporting the frequency of CYP21A2 pathogenic variants in different populations; however, few of them provide comprehensive information about Italian patients. Here, we present genetic results from a cohort of 245 unrelated Italian individuals with clinical diagnosis of CAH due to 21OHD.

METHODS

A specific polymerase chain reaction (PCR) protocol combined with Sanger sequencing was used for CYP21A2 analysis. The multiplex ligation-dependent probe amplification (MLPA) assay was employed for copy number variation (CNV) determination.

RESULTS

One hundred fourteen (46.5%) of the index cases had the NC form, 57 (23.3%) had the SV form, and 74 (30.2%) presented the SW form of the disease. The most prevalent variant found in NC patients was the p.Val282Leu (51.3%), while the most frequent variants in the classical form were p.Ile173Asn (8.6%) and c.293-13C>G (26.0%). In our study, the frequency of large rearrangements was 15.3%, with CAH-X alleles representing 40% of all DEL/CONV. In addition, 12 alleles carried rare variants, and 1 had a novel variant p.(Arg342Gln). We observed phenotype-genotype correlation in 94.7% of cases. A complete concordance was observed in Groups 0 (enzyme activity completely impaired) where all patients had the SW form as expected. In Group A (0-1% residual enzyme activity), 78.4% of patients had the anticipated SW form while 21.6% were diagnosed with the SV form. Within Group B (~ 2% residual enzyme activity), 93.4% of patients exhibited SV form and 6.5% SW disease. Finally, 92.6% and 7.4% of patients belonging to Group C (enzyme partially impaired to ~ 20-60% residual activity) exhibited NC and SV phenotypes, respectively.

CONCLUSION

This work, representing a comprehensive genetic study, expanded the CYP21A2 variants spectrum of Italian patients with 21OHD and could be helpful in prenatal diagnosis and genetic counseling.

Molecular basis and genetic testing strategies for diagnosing 21-hydroxylase deficiency, including CAH-X syndrome

Congenital adrenal hyperplasia (CAH) is a group of autosomally recessive disorders that result from impaired synthesis of glucocorticoid and mineralocorticoid. Most cases (~95%) are caused by mutations in the CYP21A2 gene, which encodes steroid 21-hydroxylase. CAH patients manifest a wide phenotypic spectrum according to their degree of residual enzyme activity. CYP21A2 and its pseudogene (CYP21A1P) are located 30 kb apart in the 6q21.3 region and share approximately 98% of their sequences in the coding region. Both genes are aligned in tandem with the C4, SKT19, and TNX genes, forming 2 segments of the RCCX modules that are arranged as STK19-C4A-CYP21A1P-TNXA-STK19B-C4B-CYP21A2-TNXB. The high sequence homology between the active gene and pseudogene leads to frequent microconversions and large rearrangements through intergenic recombination. The TNXB gene encodes an extracellular matrix glycoprotein, tenascin-X (TNX), and defects in TNXB cause Ehlers-Danlos syndrome. Deletions affecting both CYP21A2 and TNXB result in a contiguous gene deletion syndrome known as CAH-X syndrome. Because of the high homology between CYP21A2 and CYP21A1P, genetic testing for CAH should include an evaluation of copy number variations, as well as Sanger sequencing. Although it poses challenges for genetic testing, a large number of mutations and their associated phenotypes have been identified, which has helped to establish genotype-phenotype correlations. The genotype is helpful for guiding early treatment, predicting the clinical phenotype and prognosis, and providing genetic counseling. In particular, it can help ensure proper management of the potential complications of CAH-X syndrome, such as musculoskeletal and cardiac defects. This review focuses on the molecular pathophysiology and genetic diagnosis of 21-hydroxylase deficiency and highlights genetic testing strategies for CAH-X syndrome.

The prevalence and genotype of 21-hydroxylase deficiency in the Croatian Romani population

Objective

Congenital adrenal hyperplasia (CAH) owing to 21-hydroxylase deficiency (21-OHD) is a rare autosomal recessive disorder caused by pathological variants in the CYP21A2 gene. After a high prevalence of classic 21-OHD CAH in the Romani population was reported in the Republic of North Macedonia, we decided to estimate the prevalence of 21-OHD in Croatia and, if high, assess the possible causes and estimate the frequency of particular CYP21A2 variants.

Design

Cross-sectional study.

Methods

Data from a Croatian 21-OHD genetic database was reviewed, and only Romani patients were included in the study. CYP21A2 genotyping was performed using allele-specific PCR, MLPA, and Sanger sequencing.

Results

According to a survey conducted in 2017, Croatia had 22,500 Romani people and six of them had a salt-wasting (SW) form of 21-OHD. All were homozygous for the c.IVS2-13A/C-G pathological variant in intron 2 and descended from consanguineous families belonging to different Romani tribes. The calculated prevalence of 21-OHD in Croatian Romani is 1:3,750, while in the Croatian general population, it is 1:18,000. Three of the six Romani patients originated from two neighboring villages in North-western Croatia (Slavonia County), as well as the seventh patient who is of mixed Romani/Croatian descent and heterozygous for the c.IVS2-13A/C-G pathological variant (not included in the prevalence calculation).

Conclusion

A high prevalence of SW 21-OHD in the Croatian Romani population caused by the homozygous cIVS2-13A/C-G pathological variant was found. In addition to isolation and consanguinity, other possible reasons could be the heterozygous advantage of the CYP21A2 gene pathological variant and the bottleneck effect as a result of the Romani Holocaust in World War II.

Epidemiology and diagnostic trends of congenital adrenal hyperplasia in Denmark: a retrospective, population-based study

Background

The prevalence of newborns with congenital adrenal hyperplasia (CAH) detected by neonatal screening is well-described, but data including patients diagnosed later in life are extremely limited. This study aimed to describe diagnostic trends for all patients with CAH in Denmark.

Methods

A nationwide population-based registry study including medical record review.

Findings

We identified 462 patients (290 females) with any form of CAH. The prevalence of CAH combined was 15.1 (95% confidence interval [CI]: 12.3-16.1) and 9.0 (CI: 7.6-10.4) per 100,000 newborn females and males. There was a prevalence of salt-wasting (SW), simple-virilizing (SV), and non-classic (NC) CAH due to 21-hydroxylase deficiency of: SW-CAH: 6.4 (CI: 5.3-7.6) and 5.6 (CI: 4.6-6.8); SV-CAH: 2.0 (CI: 1.4-2.8) and 1.6 (CI: 1.0-2.7); and NC-CAH: 5.5 (CI: 4.4-6.9) and 2.5 (CI: 1.7-3.7) per 100,000 newborn females and males, respectively. Diagnosis of NC-CAH increased significantly during the course of the study. There was a female preponderance for SV-CAH (ratio: 1.8) and NC-CAH (ratio: 3.2). Median age at diagnosis, females and males respectively: SW-CAH: 4 (interquartile range [IQR]: 0-11) and 14 (IQR: 8-24) days, SV-CAH: 3.1 (IQR: 1.2-6.6) and 4.8 (IQR: 3.2-6.9) years, and NC-CAH: 15.5 (IQR: 7.9-22.5) and 9.4 (IQR: 7.2-23.2) years.

Interpretation

The combined prevalence of CAH was 15.1 and 9.0 per 100,000 newborn females and males, respectively. The female preponderance was primarily due to diagnosis of more females than males with NC-CAH.

Funding

International Fund of Congenital Adrenal Hyperplasia, Health Research Fund of Central Denmark Region, Aase and Einar Danielsen Fund, and "Fonden til Lægevidenskabens Fremme".

Cost-effective genotyping for classical congenital adrenal hyperplasia (CAH) due to 21-hydroxylase deficiency (21-OHD) in resource-poor settings: multiplex ligation probe amplification (MLPA) with/without sequential next-generation sequencing (NGS)

PURPOSE

Genotyping of classic congenital adrenal hyperplasia (CAH) due to 21-hydroxylase deficiency (21-OHD) is becoming increasingly significant beyond prenatal counseling in the current era of emerging gene therapy/editing technologies. While the knowledge of common variants helps in designing cost-effective genotyping strategies, limited data are currently available from the Indian subcontinent, especially South India, mainly due to financial constraints. The aim of this study is to assess the genotype of individuals with classic CAH from a South Indian cohort in a cost-effective manner.

METHODS

The genotypes of 46 unrelated subjects with classic CAH were studied through initial multiplex ligation-dependent probe amplification (MLPA) using the SALSA MLPA Probe-mix P050 CAH (MRC Holland). Next-generation sequencing (NGS) was done in 10 subjects, as their MLPA was either negative or showed heterozygous variants.

RESULTS

The common variants observed in our study population of 46 subjects were large deletions (35.8%), intron 2 variant [c.293-13A/C > G] (35.8%), 8 bp del [c.332_339del p.(Gly111Valfs*21)] (7.7%), and R356W [c.1069 C > T p.(Arg357Trp)] (6.6%). MLPA alone detected pathogenic variants in 78.2% of the initial study samples (36/46). Sequential NGS resulted in a 100% detection rate in our study population.

CONCLUSION

MLPA appears to be an effective first genotyping modality for this South Indian cohort due to the high prevalence of large deletions and common variants. MLPA as a first initial screening genotyping test with sequential NGS when required may be a cost-effective and highly sensitive approach to CYP21A2 genotyping in our part of the world and in resource-poor settings.

Salt-wasting congenital adrenal hyperplasia phenotype as a result of the TNXA/TNXB chimera 1 (CAH-X CH-1) and the pathogenic IVS2-13A/C > G in CYP21A2 gene

BACKGROUND

Genetic diversity of mutations in the CYP21A2 gene is the main cause of the monogenic congenital adrenal hyperplasia (CAH) disorder. On chromosome 6p21.3, the CYP21A2 gene is partially overlapped by the TNXB gene, the two residing in tandem with their highly homologous corresponding pseudogenes (CYP21A1P and TNXA), which leads to recurrent homologous recombination.

METHODS AND RESULTS

In the present study, the genetic status of an ethnic Greek-Cypriot family, with a female neonate that was originally classified as male and manifested the salt-wasting (SW) form, is presented. Genetic defects in the CYP21A2 and TNXB genes were investigated by Sanger sequencing multiplex ligation-dependent probe amplification (MLPA) and a real-time PCR assay. The neonate carried in compound heterozygosity the TNXA/TNXB chimeric gene complex (termed CAH-X CH-1) that results in a contiguous CYP21A2 and TNXB deletion and in her second allele the pathogenic IVS2-13A/C > G (c.655A/C > G) in CYP21A2.

CONCLUSIONS

The classic SW-CAH due to 21-hydroxylase (21-OH) deficiency may result from various complex etiological mechanisms and, as such, can involve the formation of monoallelic TNXA/TNXB chimeras found in trans with other CYP21A2 pathogenic variants. This is a rare case of CAH due to 21-hydroxylase deficiency, which elucidates the role of the complex RCCX CNV structure in the development of the disease. Identification of the correct CAH genotypes for a given phenotype is of considerable value in assisting clinicians in prenatal diagnosis, appropriate treatment, and genetic counseling.

Neonatal Screening for Congenital Adrenal Hyperplasia in Indian Newborns with Reflex Genetic Analysis of 21-Hydroxylase Deficiency

Congenital adrenal hyperplasia (CAH), screened for in neonates, is the second most common endocrinopathy after congenital hypothyroidism.Newborn screening for CAH due to CYP21A2 deficiency is performed by immunologic assay for 17-hydroxyprogesterone (17-OHP). The second-tier test for confirmation of diagnosis is carried out on recall venous blood sample from screen positives measuring 17-OHP, or other metabolites of steroid metabolism by liquid chromatography–tandem mass spectroscopy. However, as steroid metabolism is dynamic, it can affect these parameters even in the recall sample of a stressed neonate. Moreover, there is some time delay in recalling the neonate for repeat testing. Reflex genetic analysis of blood spot from the initial Guthrie cards of screen positive neonates, if used for confirmatory testing, can avoid this time delay as well as the effect of stress on steroid metabolism. In this study, we used Sanger sequencing and MLPA in a reflex manner for molecular genetic analysis to confirm CYP21A2-mediated CAH. Out of 220,000 newborns screened, 97 were positive on the initial biochemical screen, of which 54 were confirmed true positives with genetic reflex testing, giving incidence of CAH as 1:4074. Point mutations were more common than deletions, indicating that Sanger sequencing should be used ahead of MLPA for molecular diagnosis in India. Amongst the variants detected, the most common was I2G-Splice variant (44.5%), followed by c.955C>T (p.Gln319Ter) (21.2%); Del 8 bp and c.-113G>A were detected with frequencies of 20.3% and 20%, respectively. In conclusion, reflex genetic testing is an effective strategy for identifying true positives in CAH screening in neonates. This will obviate need for recall samples and also aid effective counselling and timely prenatal diagnosis in the future. In Indian newborns, as point mutations are more common than large deletions, Sanger sequencing should be the initial method of choice for genotyping, ahead of MLPA.

Synthetic glucocorticoids instead of hydrocortisone do not increase mineralocorticoid needs in adult patients with salt wasting congenital adrenal hyperplasia

It has been postulated that in patients with congenital adrenal hyperplasia (CAH) with salt wasting (SW), fludrocortisone needs might be higher in those on synthetic glucocorticoid replacement therapy in comparison to conventional hydrocortisone due to the lower mineralocorticoid activity. Here we report the results of a cross-sectional single center study comparing mineralocorticoid needs between patients taking synthetic glucocorticoids (S-GC) (N = 24) and those on conventional hydrocortisone (HC) (N = 16). We could show that while both groups took comparable HC-equivalent dosages, there was no significant difference in FC dosage (GC: 0.075 mg; IQR 0.05-0.1; HC: 0.1 mg; IQR 0.05-0.1; p = 0.713). Although there was a trend for higher renin levels in the S-GC group (67.1 µU/ml; IQR 40.5-113.9 vs. 40.4 IQR 14.2-73.1; p = 0.066), this failed to reach significance. With regard to blood pressure, those taking S-GC had even significantly elevated mean systolic (125.0 mmHg, IQR 117.5-130.0 vs 116.5 mmHg IQR 111.8-124.8; p = 0.036) and diastolic (78.0 mmHg, IQR 74.3-83.8 vs 74.5mmHG, IQR 69.3-76.0; p = 0.044) during the day. Systolic dipping was however more pronounced in those on GC in comparison to those taking HC (11.3%; IQR 8.7-14.6 vs. 6.4 IQR 3.4-12.7; p = 0.031). In conclusion, we could show in this small, albeit well-balanced cohort that mineralocorticoid dosage does not significantly differ between patients receiving synthetic glucocorticoids or conventional hydrocortisone. Higher blood pressure values despite the tendency for higher renin levels in those on S-GC support the notion that the assessment of MR adequacy should be guided by the clinical picture and blood pressure on a regular basis.

Mutation distributions among patients with congenital adrenal hyperplasia from five regions of Brazil: a systematic review

Congenital adrenal hyperplasia due to 21-hydroxylase deficiency is an autosomal recessive disorder caused by CYP21A2 gene mutations, and its molecular diagnosis is widely used in clinical practice to confirm the hormonal diagnosis. Hence, considering the miscegenation of the Brazilian population, it is important to determine a mutations panel to optimise the molecular diagnosis. The objective was to review the CYP21A2 mutations' distribution among Brazilian regions. Two reviewers screened Brazilian papers up to February 2020 in five databases. The pair-wise comparison test and Holm method were used in the statistical analysis. Nine studies were selected, comprising 769 patients from all regions. Low proportion of males and salt-wasters was identified in the North and Northeast regions, although without significant difference. Large gene rearrangements also had a low frequency, except in the Center-West and South regions (p < 0.05). The most frequent mutations were p.I172N, IVS2-13A/C>G, p.V281L and p.Q318X, and significant differences in their distributions were found: p.V281L was more frequent in the Southeast and p.Q318X in the Center-West and Northeast regions (p < 0.05). Thirteen new mutations were identified in 3.8%-15.2% of alleles, being more prevalent in the North region, and six mutations presented a founder effect gene. Genotype-phenotype correlation varied from 75.9%-97.3% among regions. The low prevalence of the salt-wasting form, affected males and severe mutations in some regions indicated pitfalls in the clinical diagnosis. The good genotype-phenotype correlation confirms the usefulness of molecular diagnosis; however, the Brazilian population also presents significant prevalence of novel mutations, which should be considered for a molecular panel.

Combining metabolomics and machine learning models as a tool to distinguish non-classic 21-hydroxylase deficiency from polycystic ovary syndrome without adrenocorticotropic hormone testing

STUDY QUESTION

Can a combination of metabolomic signature and machine learning (ML) models distinguish nonclassic 21-hydroxylase deficiency (NC21OHD) from polycystic ovary syndrome (PCOS) without adrenocorticotrophic hormone (ACTH) testing?

SUMMARY ANSWER

A single sampling methodology may be an alternative to the dynamic ACTH test in order to exclude the diagnosis of NC21OHD in the presence of a clinical hyperandrogenic presentation at any time of the menstrual cycle.

WHAT IS KNOWN ALREADY

The clinical presentation of patients with NC21OHD is similar with that for other disorders of androgen excess. Currently, cosyntropin stimulation remains the gold standard diagnosis of NC21OHD.

STUDY DESIGN, SIZE, DURATION

The study was designed using a bicentric recruitment: an internal training set included 19 women with NC21OHD and 19 controls used for developing the model; a test set included 17 NC21OHD, 72 controls and 266 PCOS patients used to evaluate the performance of the diagnostic strategy thanks to an ML approach.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Fifteen steroid species were measured in serum by liquid chromatography-mass spectrometry (LC-MS/MS). This set of 15 steroids (defined as 'steroidome') used to map the steroid biosynthesis pathway was the input for our models.

MAIN RESULTS AND THE ROLE OF CHANCE

From a single sample, modeling involving metabolic pathway mapping by profiling 15 circulating steroids allowed us to identify perfectly NC21OHD from a confounding PCOS population. The constructed model using baseline LC-MS/MS-acquired steroid fingerprinting successfully excluded all 17 NC21OHDs (sensitivity and specificity of 100%) from 266 PCOS from an external testing cohort of originally 549 women, without the use of ACTH testing. Blood sampling timing during the menstrual cycle phase did not impact the efficiency of our model.

LIMITATIONS, REASONS FOR CAUTION

The main limitations were the use of a restricted and fully prospective cohort as well as an analytical issue, as not all laboratories are equipped with mass spectrometers able to routinely measure this panel of 15 steroids. Moreover, the robustness of our model needs to be established with a larger prospective study for definitive validation in clinical practice.

WIDER IMPLICATIONS OF THE FINDINGS

This tool makes it possible to propose a new semiology for the management of hyperandrogenism. The model presents better diagnostic performances compared to the current reference strategy. The management of patients may be facilitated by limiting the use of ACTH tests. Finally, the modeling process allows a classification of steroid contributions to rationalize the biomarker approach and highlight some underlying pathophysiological mechanisms.

STUDY FUNDING/COMPETING INTEREST(S)

This study was supported by 'Agence Française de Lutte contre le dopage' and DIM Région Ile de France. This study was supported by the French institutional PHRC 2010-AOR10032 funding source and APHP. All authors declare no competing financial interests.

TRIAL REGISTRATION NUMBER

N/A.

Congenital adrenal hyperplasia

Congenital adrenal hyperplasia is a group of autosomal recessive disorders leading to multiple complex hormonal imbalances caused by various enzyme deficiencies in the adrenal steroidogenic pathway. The most common type of congenital adrenal hyperplasia is due to steroid 21-hydroxylase (21-OHase, henceforth 21OH) deficiency. The rare, classic (severe) form caused by 21OH deficiency is characterised by life-threatening adrenal crises and is the most common cause of atypical genitalia in neonates with 46,XX karyotype. After the introduction of life-saving hormone replacement therapy in the 1950s and neonatal screening programmes in many countries, nowadays neonatal survival rates in patients with congenital adrenal hyperplasia are high. However, disease-related mortality is increased and therapeutic management remains challenging, with multiple long-term complications related to treatment and disease affecting growth and development, metabolic and cardiovascular health, and fertility. Non-classic (mild) forms of congenital adrenal hyperplasia caused by 21OH deficiency are more common than the classic ones; they are detected clinically and primarily identified in female patients with hirsutism or impaired fertility. Novel treatment approaches are emerging with the aim of mimicking physiological circadian cortisol rhythm or to reduce adrenal hyperandrogenism independent of the suppressive effect of glucocorticoids.

Pseudogene TNXA Variants May Interfere with the Genetic Testing of CAH-X

CAH-X is a hypermobility-type Ehlers-Danlos syndrome connective tissue dysplasia affecting approximately 15% of patients with 21-hydroxylase deficiency (21-OHD) congenital adrenal hyperplasia (CAH) due to contiguous deletion of CYP21A2 and TNXB genes. The two most common genetic causes of CAH-X are CYP21A1P-TNXA/TNXB chimeras with pseudogene TNXA substitution for TNXB exons 35-44 (CAH-X CH-1) and TNXB exons 40-44 (CAH-X CH-2). A total of 45 subjects (40 families) from a cohort of 278 subjects (135 families of 21-OHD and 11 families of other conditions) were found to have excessive TNXB exon 40 copy number as measured by digital PCR. Here, we report that 42 subjects (37 families) had at least one copy of a TNXA variant allele carrying a TNXB exon 40 sequence, whose overall allele frequency was 10.3% (48/467). Most of the TNXA variant alleles were in cis with either a normal (22/48) or an In2G (12/48) CYP21A2 allele. There is potential interference with CAH-X molecular genetic testing based on copy number assessment, such as with digital PCR and multiplex ligation-dependent probe amplification, since this TNXA variant allele might mask a real copy number loss in TNXB exon 40. This interference most likely happens amongst genotypes of CAH-X CH-2 with an in trans normal or In2G CYP21A2 allele.

Characteristics of Congenital Adrenal Hyperplasia Diagnosed in Adulthood: A Literature Review and Case Series

Congenital adrenal hyperplasia (CAH) is a group of autosomal recessive disorders characterized by impaired cortisol synthesis. CAH, depending on its clinical form, is usually diagnosed in the neonatal period, later in childhood, in adolescence, or in young adults. Herein, we report a case series of eight individuals in whom CAH was diagnosed between the ages of 18 and 81 years.

METHODS

We report on clinical presentations, hormonal tests, adrenal/gonadal imaging, and genetic findings. The clinical data of eight people with CAH, including four women (46, XX) and four men (46, XY), were reviewed. A genetic analysis of the cytochrome P450 family 21 subfamily A member 2 (CYP21A2) gene was performed in six patients. A comprehensive literature review was also conducted.

CASE SERIES

Partial cortisol deficiency was found in all patients. The most frequent genotype was the homozygotic I173N mutation in CYP21A2. Adrenal masses were detected in seven patients, except for the youngest. Most of the patients were of short stature. Hypogonadotropic hypogonadism was detected in two males, and three females presented with primary amenorrhea. Hirsutism was noticeable in three females. All of the patients developed insulin resistance, and half of them were obese.

CONCLUSIONS

The clinical presentations of different forms of CAH overlapped. Genotype-phenotype correlations were strong but not absolute. The management of CAH should be individualized and based on clinical and laboratory findings. Furthermore, the assessment of the cortisol response to adrenocorticotrophic hormone stimulation should be mandatory in all adults with CAH. Additionally, the regular long-term screening of cardiometabolic status is required in the CAH population.

Genetic and clinical characteristics including occurrence of testicular adrenal rest tumors in Slovak and Slovenian patients with congenital adrenal hyperplasia due to 21-hydroxylase deficiency

OBJECTIVE

To analyze the mutational spectrum, clinical characteristics, genotype-phenotype correlations, testicular adrenal rests tumor prevalence, and role of neonatal screening in congenital adrenal hyperplasia (CAH) patients from Slovakia and Slovenia.

DESIGN AND METHODS

Data were obtained from 104 patients with CAH registered in Slovak and Slovenian databases. Low-resolution genotyping was performed to detect the most common point mutations. To detect deletions, conversions, point mutations, or other sequence changes in the CYP21A2 gene, high-resolution genotyping was performed. Genotypes were classified according to residual 21-hydroxylase activity (null, A, B, C).

RESULTS

64% of the individuals had the salt-wasting form (SW-CAH), 15% the simple virilizing form (SV-CAH), and 21% the non-classic (NC-CAH). CYP21A2 gene deletion/conversion and c.293-13A/C>G pathogenic variant accounted together for 55.5% of the affected alleles. In SV-CAH p.Ile172Asn was the most common pathogenic variant (28.13%), while in NC-CAH p.Val282Leu (33.33%), CYP21A2 gene deletion/conversion (21.43%), c.293-13A/C>G (14.29%), Pro30Leu (11.90%). The frequency of alleles with multiple pathogenic variants was higher in Slovenian patients (15.83% of all alleles). Severe genotypes (0 and A) correlated well with the expected phenotype (SW in 94.74% and 97.3%), while less severe genotypes (B and C) correlated weaklier (SV in 50% and NC in 70.8%). The median age of SW-CAH patients at the time of diagnosis was 6 days in Slovakia vs. 28.5 days in Slovenia (p=0.01). Most of the Slovak patients in the cohort were detected by NBS. (24 out of 29). TARTs were identified in 7 out of 24 male patients, of whom all (100%) had SW-CAH and all had poor hormonal control. The median age at the diagnosis of TARTs was 13 years.

CONCLUSION

The study confirmed the importance of neonatal screening, especially in the speed of diagnosis of severe forms of CAH. The prediction of the 21-OH deficiency phenotype was reasonably good in the case of severe pathogenic variants, but less reliable in the case of milder pathogenic variants, which is consistent compared to data from other populations. Screening for TARTs should be realized in all male patients with CAH, since there is possible remission when identified early.

Nonclassic Adrenal Hyperplasia (NCAH) due to 21-hydroxylase deficiency: A cohort of 78 patients

Diagnosis of nonclassic adrenal hyperplasia (NCAH) due to 21-hydroxylase deficiency (21-OHD) may be challenging due to its occult manifestations. To characterize clinical and molecular features of NCAH patients due to 21-hydroxylase deficiency, we retrospectively included 78 NCAH patients. Their phenotype and genotype were presented and compared. The transcription activities of novel CYP21A2 promoter variants were investigated using a dual-reporter luciferase assay system. This cohort included 53 females (68 %) and 25 males (32 %). The median of onset age was 13 years old (female: 13 range from 7 to 38; male: 11 range from 6 to 71). Menstrual cycle disorder was the most common complaint in females (62 %, n = 33) and for males, it was adrenal incidentalomas (52 %, n = 13). A total of 17 (22 %) patients complained of infertility. The most frequently variant was p.Ile173Asn (20 %, n = 31). Importantly, five variants in the promoter region including - 103/- 126 and - 196/- 296 were found in 21 (27 %) patients. Patients with promoter variants showed older onset age and less impaired hormone levels of 17-hydroxyprogesterone, ACTH, progesterone, and androstenedione. Compared with the wild-type promoter, the basic transcription activity of - 103/- 126 and - 196/- 296 promoter variants were reduced by 57% and 25%, respectively. Therefore, females with menstrual cycle disorders or infertility and males with adrenal incidentaloma should be considered of NCAH due to 21-OHD. When genotyping patients with NCAH, the promoter region of the CYP21A2 gene should be also investigated.

Genotype-phenotype correlation in patients with 21-hydroxylase deficiency

INTRODUCTION

21-hydroxylase deficiency (21OHD) is the most common cause of congenital adrenal hyperplasia (CAH). However, patients with 21OHD manifest various phenotypes due to a wide-spectrum residual enzyme activity of different CYP21A2 mutations.

METHODS

A total of 15 individuals from three unrelated families were included in this study. Target Capture-Based Deep Sequencing and Restriction Fragment Length Polymorphism was conducted on peripheral blood DNA of the three probands to identify potential mutations/deletions in CYP21A2; Sanger sequencing was conducted with the DNA from the family members of the probands.

RESULTS

Dramatically different phenotypes were seen in the three probands of CAH with different compound heterozygous mutations in CYP21A2. Proband 1 manifested simple virilizing with mutations of 30-kb deletion/c.[188A>T;518T>A], the latter is a novel double mutants classified as SV associated mutation. Although both probands carry the same compound mutations [293-13C>G]:[518T>A], gonadal dysfunction and giant bilateral adrenal myelolipoma were diagnosed for proband 2 and proband 3, respectively.

CONCLUSION

Both gender and mutations contribute to the phenotypes, and patients with the same compound mutations and gender could present with different phenotypes. Genetic analysis could help the etiologic diagnosis, especially for atypical 21OHD patients.

Genotype-phenotype association in congenital adrenal hyperplasia due to 21-hydroxylase deficiency in children

OBJECTIVE

The purpose of this study was to investigate the clinical manifestation of various forms of congenital adrenal hyperplasia (CAH) in children of the Republic of Kazakhstan, depending on their genotype.

DESIGN

The study analysed 50 patients diagnosed with CAH from 7 regions of Kazakhstan with different ethnic origins: 35 Kazakhs (70.0%), 8 Russians (16.0%), 2 Turks (4.0%), 2 Ukrainians (4.0%), 2 Uzbeks (4%), 1 Uighur (2%). All the children studied were from 0 to 18 years old, and their average age was 5.7 years ±3.9. In addition, all children were divided into groups depending on the form of the disease according to the phenotypic manifestation of the disease: salt-wasting (SW) and simple virile (SV) forms. Most of the patients suffered from SW - 32 (64.0%), and a smaller group had SV - 18 (36.0%), also one boy with SW was diagnosed with TART syndrome.

MEASUREMENTS

50 Kazakh children with the classical form of CAH were analysed. Depending on the severity of the mutations, patients were divided into 4 groups: zero groups (the most severe mutations), A, B, and C.

RESULTS

According to the results of the study, the salt-wasting form of CAH turned out to be more common than the simple virile form. A high correlation was observed in groups with mutations of high and moderate severity - 0 and A, while group C showed a strong variability of the phenotype. Thus, the correspondence between genotype and phenotype decreased along with the decrease in the severity of the disease.

CONCLUSIONS

The relationship between the genotype and the phenotype of both forms of CAH exists indirectly, through the activity of the 21-hydroxylase enzyme. Mutations in the CYP21A2 gene affect the level of the synthesized enzyme, which, in turn, determines the degree of hormone production in the blood.

Congenital adrenal hyperplasia. Role of dentist in early diagnosis

Congenital adrenal hyperplasia (CAH) is a genetic disorder characterized by an impairment of steroid synthesis due to an altered production of 21-hydroxylase enzyme. Corticoid hormones are involved in the development and functioning of many organs. The aim of the present study was to review the international literature to collect data regarding oral manifestations of CAH. A review of the literature describing oral features of patients affected by CAH was performed using electronic databases (PubMed and Scopus). The data about number of patients, form of CAH, and oral findings were extracted and analyzed. Seven studies were included in the final analysis. The principal findings reported regarded an advanced dental development observed in patients with CAH. One paper reported amelogenesis imperfecta and periodontal issues. The dentist could be the first specialist involved in the CAH syndrome diagnosis, identifying the characteristic features described above, especially for the classical simple virilizing and non-classical form.

Variant predictions in congenital adrenal hyperplasia caused by mutations in CYP21A2

CYP21A2 deficiency represents 95% of congenital adrenal hyperplasia (CAH) cases, a group of genetic disorders that affect steroid biosynthesis. The genetic and functional analysis provide critical tools to elucidate complex CAH cases. One of the most accessible tools to infer the pathogenicity of new variants is in silico prediction. Here, we analyzed the performance of in silico prediction tools to categorize missense single nucleotide variants (SNVs) of CYP21A2. SNVs of CYP21A2 characterized in vitro by functional assays were selected to assess the performance of online single and meta predictors. SNVs were tested separately or in combination with the related phenotype (severe or mild CAH form). In total, 103 SNVs of CYP21A2 (90 pathogenic and 13 neutral) were used to test the performance of 13 single-predictors and four meta-predictors. All SNVs associated with the severe phenotypes were well categorized by all tools, with an accuracy of between 0.69 (PredictSNP2) and 0.97 (CADD), and Matthews’ correlation coefficient (MCC) between 0.49 (PoredicSNP2) and 0.90 (CADD). However, SNVs related to the mild phenotype had more variation, with the accuracy between 0.47 (S3Ds&amp;GO and MAPP) and 0.88 (CADD), and MCC between 0.18 (MAPP) and 0.71 (CADD). From our analysis, we identified four predictors of CYP21A2 variant pathogenicity with good performance, CADD, ConSurf, DANN, and PolyPhen2. These results can be used for future analysis to infer the impact of uncharacterized SNVs in CYP21A2.

Genetic analysis and novel variation identification in Chinese patients with congenital adrenal hyperplasia due to 21-hydroxylase deficiency

Congenital adrenal hyperplasia owing to 21-hydroxylase deficiency is an autosomal-recessive disorder caused by mutations in the CYP21A2 gene. The aim of the study was to analyze the molecular data of 155 21-OHD patients and retrospectively investigated the common allelic mutations of CYP21A2 in 1442 Chinese 21-OHD patients. Clinical features and mutations of CYP21A2 gene in 155 unrelated 21-OHD patients were examined. Of the 155 patients, 103 cases were salt-wasting (SW) forms, 38 were simple virilizing (SV) forms and 14 were non-classical (NC) forms. In general, two types of mutations including common allelic mutations (281/310, 90.6%) and rare mutations (29/310, 9.4%) were detected, among them four novel variants c.835G>T, c.1081C>T, c.1423C>T and c.651 + 2 T > G were identified. In 1442 Chinese 21-OHD patients, the most frequently mutations were I2G (36.2%), large deletion/conversion (20.7%) and p.I173N (17.8%), while p.V282L has the lowest frequency. In this study, we provided detailed clinical data and mutation spectrum in Chinese 21-OHD patients. Moreover, four novel CYP21A2 variants (c.835G>T, c.1081C>T, c.1423C>T and c.651 +2 T > G) were identified and computational structural modeling indicated that these novel variations probably affect structural stability. Our findings improve the understanding of CYP21A2 mutational spectrum and contribute to the precise diagnosis and prenatal counseling.

Ectopic Prostate Tissue in the Uterine Cervix of a Female with Non-Classic Congenital Adrenal Hyperplasia-A Case Report

Introduction: The occurrence of ectopic prostate tissue in the female genital tract is rare and has only been described sporadically. The origin of these lesions is unclear, but their appearance seems to be associated with various forms of androgen excess, including androgen therapy for transgender treatment or disorders of sex development, such as classic congenital adrenal hyperplasia (CAH). This is the first described case of ectopic prostate tissue in the cervix uteri of a 46,XX patient with a confirmed diagnosis of non-classic CAH due to 21-OHD and a history of mild adrenal androgen excess. Case presentation: We describe a 34-year-old patient with a genetic diagnosis of non-classic CAH due to 21-hydroxylase deficiency (21-OHD) with a female karyo- and phenotype and a history of mild adrenal androgen excess. Due to dysplasia in the cervical smear, conization had to be performed, revealing ectopic prostate tissue in the cervix uteri of the patient. Conclusions: An association between androgen excess and the occurrence of prostate tissue is likely and should therefore be considered as a differential diagnosis for atypical tissue in the female genital tract.

C. elegans as a model for inter-individual variation in metabolism

Individuals can exhibit differences in metabolism that are caused by the interplay of genetic background, nutritional input, microbiota and other environmental factors1-4. It is difficult to connect differences in metabolism to genomic variation and derive underlying molecular mechanisms in humans, owing to differences in diet and lifestyle, among others. Here we use the nematode Caenorhabditis elegans as a model to study inter-individual variation in metabolism. By comparing three wild strains and the commonly used N2 laboratory strain, we find differences in the abundances of both known metabolites and those that have not to our knowledge been previously described. The latter metabolites include conjugates between 3-hydroxypropionate (3HP) and several amino acids (3HP-AAs), which are much higher in abundance in one of the wild strains. 3HP is an intermediate in the propionate shunt pathway, which is activated when flux through the canonical, vitamin-B12-dependent propionate breakdown pathway is perturbed5. We show that increased accumulation of 3HP-AAs is caused by genetic variation in HPHD-1, for which 3HP is a substrate. Our results suggest that the production of 3HP-AAs represents a 'shunt-within-a-shunt' pathway to accommodate a reduction-of-function allele in hphd-1. This study provides a step towards the development of metabolic network models that capture individual-specific differences of metabolism and more closely represent the diversity that is found in entire species.

Clinical, biochemical, and biomolecular aspects of congenital adrenal hyperplasia in a group of Cameroonian children and adolescents

OBJECTIVES

Congenital adrenal hyperplasia (CAH) remains one of the most challenging endocrine disorders to diagnose, manage, and treat, especially in Africa where there is lack of neonatal screening program, and limited access to care. Data on biomolecular anomaly are sparse, therefore type of mutations are unknown, increasing management challenges and genetic counseling. The present study aims to describe clinical, biomolecular aspects of a group of Cameroonian patients.

METHODS

We did an observational retrospective study at the pediatric endocrinology unit of the Mother and Child Centre of the Chantal Biya Foundation in Yaounde from May 2013 to December 2019, including all patients diagnosed with CAH.

RESULTS

We consecutively included 31 patients aged less than 21 years, diagnosed CAH. Median age at diagnosis was 1.71 years (IQR 0.08-2.57 years). Abnormal genitalia was the main complain in 48.4%(n=15). The most prevalent genetic anomaly found in our study population (n=24) was on CYP11, found in 16 patients (66.6%) followed by CYP21A2 mutation found in 8 patients. Homozygous mutation of p.Q356X was found in half of patients with 11 hydroxylase deficiency. This mutation was mostly found in people from semi-Bantu tribes, declared non consanguineous.

CONCLUSIONS

11 hydroxylase deficiency is the most prevalent form of CAH found in this group of Cameroonian children.

Molecular analysis and genotype-phenotype correlations in patients with classical congenital adrenal hyperplasia due to 21-hydroxylase deficiency from southern Poland - experience of a clinical center

PURPOSE

The prevalence of CYP21A2 gene variants and genotype-phenotype correlations are variable among populations. The aim of this study was to characterize CYP21A2 gene variants in adult patients with classical congenital adrenal hyperplasia (CCAH) from southern Poland and to analyze genotype-phenotype correlations.

MATERIALS/METHODS

A total of 48 patients (30 women and 18 men) with CCAH were included in the study. Patients were divided into two clinical subgroups, namely, salt-wasting (SW) - 38 patients and simple virilizing (SV) - 10 patients. A genetic analysis MLPA (multiplex ligation-dependent probe amplification) was performed in all of them. In dubious cases, the analysis was complemented by Sanger sequencing. Genotypes were classified into five groups (depending on the residual in vitro enzymatic activity), namely, null, A, B, C, and D, and correlated with the clinical picture.

RESULTS

Molecular defects were investigated and identified in 48 patients. The most common variant in the studied group was I2G, followed by whole or partial gene copy deletion, and I172N. One novel variant c.[878G>T] (p.Gly293Val) was found. In nine patients, a non-concordance between genotype and phenotype was observed. Genotype-phenotype correlations measured by positive predictive value (PPV) were as follows: 100% in group null, 90.5% in group A, and 66.7% in group B.

CONCLUSIONS

CYP21A2 variants in the studied cohort were similar to values previously reported in other countries of the region. There was a good correlation between genotype and phenotype in the null and A groups, the correlation being considerably lower in group B.

Classical and non-classical congenital adrenal hyperplasia: what is the difference in subsequent fertility?

21-Hydroxylase deficiency (21OHD) is the most common cause of congenital adrenal hyperplasia. Increased production of adrenal-derived androgens and progesterone in 21OHD women interfere with their reproductive function and their fertility in many different ways, depending on the severity of the disease. Sexuality and fertility in women with classic 21OHD is impaired, due to several issues such as disrupted gonadotropic axis due to androgen and progesterone overproduction, and mechanical, psychological factors related to genital surgery. Fertility and fecundity in these women get better over the years. Subfertility seems contrariwise to be relative in non-classic 21OHD women. Before pregnancy, genotyping the partner and genetic counselling is mandatory.

Treatment of congenital adrenal hyperplasia in children aged 0-3 years: a retrospective multicenter analysis of salt supplementation, glucocorticoid and mineralocorticoid medication, growth and blood pressure

OBJECTIVES

International guidelines recommend additional salt supplementation during infancy in classic congenital adrenal hyperplasia (CAH) due to 21-hydroxylase deficiency. The influence of corticoid medication and growth has not been assessed.

AIM

To investigate the current use of salt supplementation, fludrocortisone (FC) and hydrocortisone (HC) dosage as well as weight, height, BMI and blood pressure (BP) in CAH children aged 0-3 years.

METHODS

Retrospective multicentre analysis using data from the I-CAH registry. Salt-treated (ST) and non-salt-treated (NST) children were compared regarding FC and HC dosage, weight, height and BP at 0, 3, 6, 9, 12, 18, 24, 30, and 36 months.

RESULTS

We analysed 2483 visits of 331 patients born after year 2000 in 13 countries (male, n = 145) with 203 ST patients (61%). NST children had significantly higher FC dosages at 1.5-4.5 months and higher HC dosages until 1.5 months of age. No differences in weight, length and BP between subgroups were observed. Children of the whole cohort showed increased BMI-SDS during the study period and about half of the reported BP readings were >P95.

CONCLUSION

In children treated with additional salt supplementation, FC and HC dosages are lower during the first months of life but without differences in weight, length and BP until 3 years of age compared to NST children. All children showed an increase in BMI-SDS and a high rate of BP readings >P95 until 3 years, indicating the start of weight gain and negative effects on blood pressure already in very early life.

CONGENITAL ADRENAL HYPERPLASIA WITH COMPOUND HETEROZYGOUS I2 SPLICE AND P453S MUTATIONS

BACKGROUND

Congenital adrenal hyperplasia (CAH) is an autosomal recessive inherited disorder caused by congenital deficiency of enzymes involved in cortisol biosynthesis from cholesterol in the adrenal cortex. In this article, we aimed to present a 29-year-old female patient with I2 splice point mutation detected in one allele and P453S mutation on the other allele of CYP21A2 gene associated with 21-hydroxylase deficiency. Her further investigation revealed that her mother had P453S mutation and her father had I2 splice mutation.

CASE REPORT

A 29-year-old woman with CAH was admitted to our clinic with the request of pregnancy. Her physical examination revealed a height of 151 cm, weight 59 kg, body mass index 25.8 kg/m². According to Tanner staging, she had Stage 3 breast development and pubic hair. Her laboratory test results were as follows: Glucose: 79 mg/dL (70-100 mg/dL), Creatinine: 0.6 (0.5-0.95 mg/dL), Sodium: 138 mEq/L (135-145 mEq/L), Potassium: 4.4 mEq/L (3.5-5.1 mEq/L), Cortisol: 0.05 µg/dL, ACTH: <5.00 pg/mL (5-46 pg/mL), 17-OH progesterone: 7.67 ng/mL (0-3 ng/mL). Chromosome analysis revealed a 46, XX karyotype. CYP21A2 gene mutation analysis was performed for the patient whose clinical history and laboratory results were compatible with congenital adrenal hyperplasia. During the reverse dot blot analysis, I2 splice mutation in one allele and P453S mutation in the other allele were detected.

CONCLUSION

Although the I2 splice mutation detected in our case was mostly associated with a salt-wasting form of CAH, it was thought that the other P453S mutation detected may explain the relatively good clinical course in our case.

Pathogenic variants in the CYP21A2 gene cause isolated autosomal dominant congenital posterior polar cataracts

BACKGROUND

Congenital cataracts are the most common cause of visual impairment worldwide. Inherited cataract is a clinically and genetically heterogeneous disease. Here we report disease-causing variants in a novel gene, CYP21A2, causing autosomal dominant posterior polar cataract. Variants in this gene are known to cause autosomal recessive congenital adrenal hyperplasia (CAH).

METHODS

Using whole-exome sequencing (WES), we have identified disease-causing sequence variants in two families of British and Irish origin, and in two isolated cases of Asian-Indian and British origin. Bioinformatics analysis confirmed these variants as rare with damaging pathogenicity scores. Segregation was tested within the families using direct Sanger sequencing.

RESULTS

A nonsense variant NM_000500.9 c.955 C > T; p.Q319* was identified in CYP21A2 in two families with posterior polar cataract and in an isolated case with unspecified congenital cataract phenotype. This is the same variant previously linked to CAH and identified as Q318* in the literature. We have also identified a rare missense variant NM_000500.9 c.770 T > C; p.M257T in an isolated case with unspecified congenital cataract phenotype.

CONCLUSION

This is the first report of separate sequence variants in CYP21A2 associated with congenital cataract. Our findings extend the genetic basis for congenital cataract and add to the phenotypic spectrum of CYP21A2 variants and particularly the CAH associated Q318* variant. CYP21A2 has a significant role in mineralo- and gluco-corticoid biosynthesis. These findings suggest that CYP21A2 may be important for extra-adrenal biosynthesis of aldosterone and cortisol in the eye lens.

Cardiometabolic Health in Adolescents and Young Adults with Congenital Adrenal Hyperplasia

Background and objectives: Data on long-term cardiometabolic consequences in patients with congenital adrenal hyperplasia (CAH) are controversial. The aim of our study was to evaluate body mass index (BMI), body composition, blood pressure (BP) and insulin sensitivity in adolescents and young adults with CAH in comparison with healthy controls. Methods: Thirty-two patients with classical CAH (13 males; mean of age 26.0 ± 7.1, years (14.0−37.3) were compared to 32 healthy sex and age-matched controls (13 males; mean of age 28.7 ± 4.6 years (14.1−37.2), p = 0.13). Body composition was evaluated in all subjects with DXA (Hologic Inc., Bedford, MA, USA). Elevated BP was defined as BP > 95th percentile in adolescents, and >140/90 mmHg in adults. Comparisons between the two groups were adjusted for age, gender, pubertal stage and height. An oral glucose tolerance test was performed, and fasting insulin levels were evaluated. Insulin sensitivity was determined using a homeostasis model assessment of insulin resistance index (HOMA-IR). Results: The median BMI was significantly higher in subjects with CAH (1.63 (0.3−2.4) SDS and 0.41 (−0.63−1.19) SDS, respectively, p < 0.001). Visceral adipose tissue (VAT) in grams was significantly higher in CAH females versus control females (467 (231−561) vs. 226 (164−295), p = 0.002). Elevated BP was identified in 34% of CAH patients (nine SW and two SV) and 12.5% (n = 4) of controls (p = 0.038). Impaired fasting glycemia was detected in one SW CAH patient and impaired glucose tolerance in three SV CAH patients; normal glucose tolerance was found in all controls. A strong positive correlation was found between median cumulative hydrocortisone (HC) dose equivalents and LDL-cholesterol and a negative association with lean body mass (r = −0.79, p = 0.036) in females with CAH. BMI, VAT, BP and HOMA-IR were not related to median cumulative HC dose equivalents. Conclusions: CAH patients had higher BMI, VAT and frequency of elevated BP compared to controls. Doses of glucocorticoids were related directly to LDL-cholesterol and inversely to lean body mass in CAH females, but not associated with body composition, insulin sensitivity and BP in the whole cohort of CAH patients.

Molecular Diagnosis of Steroid 21-Hydroxylase Deficiency: A Practical Approach

Adrenal insufficiency in paediatric patients is mostly due to congenital adrenal hyperplasia (CAH), a severe monogenic disease caused by steroid 21-hydroxylase deficiency (21-OHD, encoded by the CYP21A2 gene) in 95% of cases. CYP21A2 genotyping requires careful analyses that guaranty gene-specific PCR, accurate definition of pseudogene-gene chimeras, gene duplications and allele dropout avoidance. A small panel of well-established disease-causing alterations enables a high diagnostic yield in confirming/discarding the disorder not only in symptomatic patients but also in those asymptomatic with borderline/positive results of 17-hydroxyprogesterone. Unfortunately, the complexity of this locus makes it today reluctant to high throughput techniques of massive sequencing. The strong relationship existing between the molecular alterations and the degree of enzymatic deficiency has allowed genetic studies to demonstrate its usefulness in predicting/classifying the clinical form of the disease. Other aspects of interest regarding molecular studies include its independence of physiological variations and analytical interferences, its usefulness in the diagnosis of simple virilizing forms in males and its inherent contribution to the genetic counseling, an aspect of great importance taking into account the high carrier frequency of CAH in the general population. Genetic testing of CYP21A2 constitutes an irreplaceable tool to detect severe alleles not just in family members of classical forms but also in mild late-onset forms of the disease and couples. It is also helpful in areas such as assisted reproduction and preimplantation diagnosis. Molecular diagnosis of 21-OHD under expert knowledge definitely contributes to a better management of the disease in every step of the clinical course.

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.

Copy Number Variations in Genetic Diagnosis of Congenital Adrenal Hyperplasia Children

Background: Congenital adrenal hyperplasia (CAH) is a monogenic disorder caused by genetic diversity in the CYP21A2 gene, with 21-hydroxylase deficiency (21-OHD) as the most common type. Early sex assignment and early diagnosis of different genetic variations with a proper technique are important to reduce mortality and morbidity. Proper early sex identification reduces emotional, social, and psychological stress.

Aim: Detection of a spectrum of aberrations in the CYP21A2 gene, including copy number variations, gene conversion, chimeric genes, and point variations.

Methods: The CYP21A2 gene was screened using MLPA assay in 112 unrelated Egyptian children with 21-OHD CAH (33 males and 79 females).

Results: In the studied group, 79.5% were diagnosed within the first month of life. 46.8% of the genetic females were misdiagnosed as males. Among the copy number variation results, large deletions in 15.4% and three types of chimeric genes in 9% (CH-1, CH-7, and CAH-X CH-1) were detected. Regarding gene dosage, one copy of CYP21A2 was found in 5 cases (4.5%), three copies were detected in 7 cases (6.3%), and one case (0.9%) showed four copies. Eight common genetic variants were identified, I2G, large deletions, large gene conversion (LGC), I172N, F306 + T, -113 SNP, 8bp Del, and exon 6 cluster (V237E and M239K) with an allelic frequency of 32.62%, 15.45%, 7.30%, 3.00%, 2.58%, 2.15%, 0.86%, and 0.86%, respectively.

Conclusion: High prevalence of copy number variations highlights the added value of using MLPA in routine laboratory diagnosis of CAH patients.

Genotypic spectrum of 21-hydroxylase deficiency in an endogamous population

BACKGROUND

Congenital adrenal hyperplasia (CAH) due to autosomal recessive 21-hydroxylase deficiency (21-OHD) is caused by defects in the CYP21 (CYP21A2) gene. Several mutations have been identified in the CYP21 (CYP21A2) gene of patients with 21-OHD. We aimed at determining the frequency of these mutations among a group of Egyptian patients and studying the genotype-phenotype correlation.

METHODS

Forty-seven patients with CAH due to 21-OHD from 42 different families diagnosed by clinical and hormonal evaluation and classified accordingly into salt wasting (SW) and simple virilizing (SV) phenotypes were enrolled. Their ages ranged between 1.78 and 18.99 years. Molecular analysis of the CYP21 (CYP21A2) gene was performed for the detection of eleven common mutations: P30L, I2 splice (I2 G), Del 8 bp E3 (G110del8nt), I172N, cluster E6 (I236N, V237E, M239K), V281L, L307 frameshift (F306 + T), Q318X, R356W, P453S, R483P by polymerase chain reaction (PCR) and reverse hybridization.

RESULTS

Disease-causing mutations were identified in 47 patients, 55.31% of them were compound heterozygous. The most frequent mutations were I2 splice (25.43%), followed by cluster E6 (16.66%) and P30L (15.78%). Two point mutations (P453S, R483P) were not identified in any patient. In the SW patients, genotypes were more compatible with their phenotypes.

CONCLUSION

Molecular characterization should be considered along with clinical and biochemical diagnosis of CAH since it could confirm the diagnosis, outline the treatment strategy and morbidity, and ensure proper genetic counseling.