Differences in hormonal levels between heterozygous CYP21A2 pathogenic variant carriers, non-carriers, and females with non-classic congenital hyperplasia

ABSTRACT Objective: CYP21A2 mutation heterozygote carriers seem to have an increased risk of hyperandrogenism. However, the clinical relevance of the heterozygote carrier status and the reliability of hormonal testing in discriminating a carrier from a non-carrier are puzzling questions. We aimed to characterize a population of Portuguese females suspected of having non-classic congenital adrenal hyperplasia (NC-CAH) due to clinical and biochemical criteria and who have undergone CYP21A2 molecular analysis. Subjects and methods: Retrospectively, we have analyzed the clinical records of 131 females (32 girls aged 3-9 and 99 adolescents and premenopausal women aged 13-49) who underwent complete CYP21A2 molecular analysis due to suspicion of NC-CAH. We divided included participants into three groups according to the CYP21A2 molecular analysis: NC-CAH females (46), heterozygous carriers (49), and wild type (36). We then compared clinical signs and symptoms as well as biochemical and molecular data between carriers and NC-CAH individuals and between carriers and wild type females. We measured 17OHP by electrochemiluminescence immunoassay. Results: Clinical features were similar between groups. Heterozygous carriers presented higher basal and post-cosyntropin 17-hydroxyprogesterone (17OHP) than wild type individuals (p < 0.05) and lower basal and stimulated 17OHP levels than NC-CAH patients (p < 0.05). We discovered a considerable overlap between 17OHP levels among groups. The most common pathogenic variant we identified was p.Val282Leu. Conclusion: In this population of hyperandrogenic women and children, heterozygous carriers showed higher basal and stimulated 17OHP than non-carriers although normal basal and stimulated 17OHP responses do not exclude heterozygosity for CYP21A2 pathogenic variants. In this study, only the molecular analysis presented good sensitivity in identifying heterozygotes.

Differences in hormonal levels between heterozygous CYP21A2 pathogenic variant carriers, non-carriers, and females with non-classic congenital hyperplasia.

Objective: CYP21A2 mutation heterozygote carriers seem to have an increased risk of hyperandrogenism. However, the clinical relevance of the heterozygote carrier status and the reliability of hormonal testing in discriminating a carrier from a non-carrier are puzzling questions. We aimed to characterize a population of Portuguese females suspected of having non-classic congenital adrenal hyperplasia (NC-CAH) due to clinical and biochemical criteria and who have undergone CYP21A2 molecular analysis. Methods: Retrospectively, we have analyzed the clinical records of 131 females (32 girls aged 3-9 and 99 adolescents and premenopausal women aged 13-49) who underwent complete CYP21A2 molecular analysis due to suspicion of NC-CAH. We divided included participants into three groups according to the CYP21A2 molecular analysis: NC-CAH females (46), heterozygous carriers (49), and wild type (36). We then compared clinical signs and symptoms as well as biochemical and molecular data between carriers and NC-CAH individuals and between carriers and wild type females. We measured 17OHP by electrochemiluminescence immunoassay. Results: Clinical features were similar between groups. Heterozygous carriers presented higher basal and post-cosyntropin 17-hydroxyprogesterone (17OHP) than wild type individuals (p < 0.05) and lower basal and stimulated 17OHP levels than NC-CAH patients (p < 0.05). We discovered a considerable overlap between 17OHP levels among groups. The most common pathogenic variant we identified was p.Val282Leu. Conclusion: In this population of hyperandrogenic women and children, heterozygous carriers showed higher basal and stimulated 17OHP than non-carriers although normal basal and stimulated 17OHP responses do not exclude heterozygosity for CYP21A2 pathogenic variants. In this study, only the molecular analysis presented good sensitivity in identifying heterozygotes.

Congenital Adrenal Hyperplasia Due to 21-Hydroxylase Deficiency: An Update on Genetic Analysis of CYP21A2 Gene.

Congenital Adrenal Hyperplasia is a group of genetic autosomal recessive disorders that affects adrenal steroidogenesis in the adrenal cortex. One of the most common defects associated with Congenital Adrenal Hyperplasia is the deficiency of 21-hydroxylase enzyme, responsible for the conversion of 17-hydroxyprogesterone to 11-deoxycortisol and progesterone to deoxycorticosterone. The impairment of cortisol and aldosterone production is directly related to the clinical form of the disease that ranges from classic or severe to non-classic or mild late onset. The deficiency of 21-hydroxylase enzyme results from pathogenic variants on CYP21A2 gene that, in the majority of the cases, compromise enzymatic activity and are strongly correlated with the clinical severity of the disease. Due to the exceptionally high homology and proximity between the gene and the pseudogene, more than 90% of pathogenic variants result from intergenic recombination. Around 75% are deleterious variants transferred from the pseudogene by gene conversion, during mitosis. About 20% are due to unequal crossing over during meiosis and lead to duplications or deletions on CYP21A2 gene. Molecular genetic analysis of CYP21A2 variants is of major importance for confirmation of clinical diagnosis, predicting prognosis and for an appropriate genetic counselling. In this review we will present an update on the genetic analysis of CYP21A2 gene variants in CAH patients performed in our department.

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

[This corrects the article on p. 432 in vol. 10, PMID: 31333583.].

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.

CYP21A2 Gene Pathogenic Variants: A Multicenter Study on Genotype-Phenotype Correlation from a Portuguese Pediatric Cohort.

BACKGROUND: Congenital adrenal hyperplasia (CAH) due to 21-hydroxylase deficiency (21OHD) is an autosomal recessive disorder characterized by 3 overlapping phenotypes: salt-wasting (SW), simple virilizing (SV), and non-classic (NC). We aimed at conducting a nationwide genotype description of the CAH pediatric patients and to establish their genotype-phenotype correlation. METHODS: CAH patients were recruited from Portuguese pediatric endocrinology centers and classified as SW, SV, or NC. Genetic analysis was performed by polymerase chain reaction (sequence specific primer, restriction fragment length polymorphism) or direct Sanger sequencing. Genotypes were categorized into 4 groups (0, A, B, and C), according to their predicted enzymatic activity. In each group, the expected phenotype was compared to the observed phenotype to assess the genotype-phenotype correlation. RESULTS: Our cohort comprises 212 unrelated pediatric CAH patients (29% SW, 11% SV, 60% NC). The most common pathogenic variant was p.(Val282Leu; 41.3% of the 424 alleles analyzed). The p.(Val282Leu) variant, together with c.293-13A/C>G, p.(Ile173Asn), p.(Leu308Thr), p.(Gln319*), and large deletions/conversions were responsible for 86.4% of the mutated alleles. Patients' stratification by disease subtype revealed that the most frequent pathogenic variants were c.293-13A/C>G in SW (31.1%), p.(Ile173Asn) in SV (46.9%), and p.(Val282Leu) in NC (69.5%). The most common genotype was homozygosity for p.(Val282Leu; 33.0%). Moreover, we found 2 novel variants: p.(Ile161Thr) and p.(Trp202Arg), in exons 4 and 5, respectively. The global genotype-phenotype correlation was 92.4%. Group B (associated with the SV form) showed the lowest genotype-phenotype correlation (80%). CONCLUSION: Our cohort has one of the largest NC CAH pediatric populations described. We emphasize the high frequency of the p.(Val282Leu) variant and the very high genotype-phenotype correlation observed.

Preimplantation genetic testing for Huntington disease: the perspective of one Portuguese center.

BACKGROUND: Huntington disease (HD) is an autosomal dominant late-onset neurodegenerative disease caused by an unstable cytosine-adenine-guanine trinucleotide repeat expansion in the huntingtin (HTT) gene. Preimplantation genetic testing (PGT) is a diagnostic procedure available for these individuals, because they carry a high risk of transmitting this genetic condition to their offspring. METHODS: Information about 15 HD couples referred for PGT and 21 cycles performed from 2009 to 2018 was collected retrospectively. PGT provide direct testing of embryos obtained after intracytoplasmic sperm injection, using polymerase chain reaction multiplex as the genetic testing protocol. RESULTS: PGT for HD was performed in 15 couples, with no history of previous attempts, in a total of 21 cycles. The mean number of biopsied embryos per cycle was 4.9. The amplification efficiency in blastomeres was 87.4%. From the 90 amplified embryos, 32 were normal and suitable for transfer. The mean number of transferred embryos per couple was 1.2.Overall, 3 positive human chorionic gonadotropin tests were obtained in 3 couples, resulting in 2 clinical pregnancies. The 2 ongoing clinical pregnancies had normal evolution, and culminated in 2 deliveries, resulting in the birth of 2 healthy children. CONCLUSIONS: PGT for HD is considered an effective and safe reproductive option for couples who are at risk of transmitting HD, when proper genetic and reproductive counseling is warranted.

AN69-ST membrane, a useful option in two cases of severe dialysis reactions.

Adverse reactions during hemodialysis (HD) sessions although infrequent can be severe. We report two cases of recurrent adverse reactions to HD biocompatible synthetic membranes. Change to AN-69 dialyzer allowed subsequent uneventful HD sessions. This may be due to the surface treated membrane, which provides greater adsorption capacity and improved biocompatibility.

Complete mole in a dichorionic twin pregnancy after intracytoplasmic sperm injection.

A dichorionic twin pregnancy with complete hydatidiform mole and coexistent fetus is a rare and challenging situation, whose pathogenesis has not been yet fully understood. We present a case of a 39-year-old woman who underwent intracytoplasmic sperm injection with two embryos transfer. The 12-week gestation ultrasound examination revealed normal fetus and placenta with features of hydatidiform mole, leading to pregnancy termination. Autopsy and histological examinations diagnosed a complete mole coexisting with a normal fetus, and the genetic analysis showed a diploid fetus with biparental genome and molar tissue with paternal diploidy. This case highlighted that complete molar pregnancies may still occur even though pregnancy is achieved after intracytoplasmic sperm injection. A review of the literature was performed by collecting data from the few similar reported cases and by commenting on the pathogenesis of this rare condition.

Complete mole in a dichorionic twin pregnancy after intracytoplasmic sperm injection / Mola hidatiforme completa em gravidez bicoriônica após injecção intracitoplasmática de espermatozoides

A dichorionic twin pregnancy with complete hydatidiform mole and coexistent fetus is a rare and challenging situation, whose pathogenesis has not been yet fully understood. We present a case of a 39-year-old woman who underwent intracytoplasmic sperm injection with two embryos transfer. The 12-week gestation ultrasound examination revealed normal fetus and placenta with features of hydatidiform mole, leading to pregnancy termination. Autopsy and histological examinations diagnosed a complete mole coexisting with a normal fetus, and the genetic analysis showed a diploid fetus with biparental genome and molar tissue with paternal diploidy. This case highlighted that complete molar pregnancies may still occur even though pregnancy is achieved after intracytoplasmic sperm injection. A review of the literature was performed by collecting data from the few similar reported cases and by commenting on the pathogenesis of this rare condition.

Uma gravidez bicoriônica com mola hidatiforme completa e feto normal é uma situação rara e desafiadora, cuja patogênese não foi ainda totalmente compreendida. Apresenta-se o caso de uma mulher de 39 anos submetida à injeção intracitoplasmática de espermatozoides com transferência de dois embriões. Na ecografia pré-natal realizada na 12ª semana de gestação, foi identificado um embrião morfologicamente normal e uma placenta com características molares. Esta situação resultou na terminação eletiva da gravidez. A autópsia e o estudo histológico permitiram o diagnóstico definitivo de uma mola hidatiforme completa coexistindo com feto normal. A análise genética mostrou feto diploide com genoma biparental e tecido molar com diploidia paterna. Este caso ressaltou que as gestações com mola hidatiforme completa poderão ainda ocorrer, mesmo que a gravidez seja realizada após uma injeção intracitoplasmática de espermatozoides. Foram realizadas uma revisão dos raros casos descritos na literatura e uma explicação da patogenia desta condição rara.

Application of touch FISH in the study of mosaic tetraploidy and maternal cell contamination in pregnancy losses.

PURPOSE: karyotype is a well established technique in the study of spontaneous miscarriages but is associated with selective overgrowth of maternal cells and other culture artefact (spp) such as tetraploidy, which could mask the true karyotype of the conceptus. METHODS: 328 cases of pregnancy losses were studied by karyotype and Multiplex Ligation Dependent Probe Amplification technique. Touch FISH performed in non-cultured cells was used to evaluate the ploidy complement and sex discrepancies using centromeric probes for chromosomes X, Y and 18. RESULTS: touch FISH confirmed 13 cases of maternal contamination, identified a triploidy and a monosomy X. True tetraploidy was confirmed in 7/14 cases studied. CONCLUSION: touch FISH protocol is extremely accurate in the distinction of genuine mosaicism from tissue culture artifacts namely in cases with suspicion of tetraploidy and can be used to confirm maternal cell contamination in cases with sex discrepancy between karyotype and MLPA.

Aneuploidies detection in miscarriages and fetal deaths using multiplex ligation-dependent probe amplification: an alternative for speeding up results?

OBJECTIVE: The aim of this prospective study was to apply the MLPA technique to products of miscarriages and fetal deaths in order to detect the more frequent chromosome aneuploidies and compare the results to conventional karyotyping. STUDY DESIGN: Multiplex ligation-dependent probe amplification (MLPA) is a relatively new molecular technique for targeted detection of common chromosomal aneuploidies, namely trisomy 13, 18, 21 and sex chromosomal abnormalities. The reliability and high accuracy of this technique constitute an alternative for rapid results in large scale testing. In this study, a total of 489 DNA samples from fetal tissue were used for aneuploidy detection of chromosomes 13, 18, 21, X and Y using a commercial MLPA kit (SALSA P095) and were simultaneously subjected to conventional karyotyping. RESULTS: MLPA was the only result available in 33% of the cases. A cytogenetic result was obtained in only 328/489 samples. MLPA detected 7.8% of chromosome aneuploidies. Among the total samples karyotyped, MLPA failed to detect some aneuploidies and the false-negative rate was 0.82%. As expected, ploidy changes and reciprocal translocations were not detected by this technique, but MLPA gave a conclusive result even in cases of mosaicism. CONCLUSION: The present data confirm that MLPA is a rapid, simple and reliable method for detection of chromosome 13, 18, 21, X and Y abnormalities in fetal tissue.

Treatment of severe dialysis reactions with the AN69-ST membrane: biocompatibility does matter.

Dialysis reactions with biocompatible membranes are rare, and complement activation has been suggested to be a culprit. We report here a case of an incident haemodialysis patient with asthma disease who experienced severe adverse reactions late into dialysis session, with different synthetic membranes (FX 80, Fresenius; Polyflux 17L, Gambro; FX 10, Fresenius; BLS 512, Bellco-Sorin). After replacing the dialyser by the surface-treated AN69 membrane (Nephral ST 500, Hospal), the dialysis sessions became uneventful. The case reinforces the need for biocompatible dialysers with high permeability and adsorptive capacity in susceptible patients experiencing severe dialysis reactions with synthetic membranes.

Aminoterminal B-type natriuretic peptide (NT-proBNP) in end-stage renal failure patients on regular hemodialysis: does it have diagnostic and prognostic implications?

BACKGROUND: Amino-terminal B-type natriuretic peptide (NT-proBNP) quantification is a useful cardiovascular diagnostic and prognostic test. In renal failure its use may have constraints, as it depends on renal clearance. We aimed to evaluate the clinical usefulness of NT-proBNP in hemodialysis (HD) patients. METHODS: We measured NT-proBNP levels in 44 patients before and after a regular high-flux HD. Cardiac parameters were evaluated by echocardiography. Patients were followed up for 656.5 +/- 476.4 days for the occurrence of hospital admission or death. RESULTS: NT-proBNP levels decreased after HD (p < 0.0001) without correlation with ultrafiltration volume, Kt/V index, weight decrease or pulse pressure decrease. Pre- and post-HD NT-proBNP were similar in patients with and without left ventricular hypertrophy. Pre-HD levels were not significantly associated with prognosis, probably due to a type 2 error; post-HD NT- proBNP and NT-proBNP reduction ratio (RR) were predictive of the outcome by Kaplan-Meier analysis, but only RR remained associated with prognosis on multivariate regression analysis (hazard ratio 0.96; 95% confidence interval 0.93-0.99). CONCLUSION: Our results do not support the use of NT-proBNP in the diagnosis of left ventricular hypertrophy or volume status in HD patients, but suggest its utility in prognostic stratification. HD-related variation in NT-proBNP was associated with prognosis.

Identification, characterization and clinical implications of two markers detected at prenatal diagnosis.

OBJECTIVES: Marker chromosomes are relatively rare in the general population as its identification at prenatal diagnosis. In this article, we identified and characterized two de novo supernumerary marker chromosomes in a mosaic form at prenatal diagnosis. METHODS: The two cases presented were detected during prenatal diagnosis at 17 and 15 weeks of gestation. The analyses were performed due to the advanced maternal age. In both cases, parent's karyotypes were normal. The identification of the marker chromosomes was possible by FISH techniques. RESULTS: One marker chromosome was derived from chromosome 5 and the other from chromosome 6. Both children are well at the moment. CONCLUSION: The two cases described in the present paper, join to the ones already described in the literature. However these results are the first ones without any phenotypical anomalies, at least until the present. Every new characterization of marker chromosomes at prenatal diagnosis should be reported for determining a genotype-phenotype correlation, and thus be used for genetic counselling and risk evaluation.