Genotype-phenotype correlations in children and adolescents with nonclassical congenital adrenal hyperplasia due to 21-hydroxylase deficiency

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.

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.

Non-PCOS Hyperandrogenic Disorders in Adolescents

Hyperandrogenism-clinical features resulting from increased androgen production and/or action-is not uncommon in peripubertal girls. Hyperandrogenism affects 3 to 20% of adolescent girls and often is associated with hyperandrogenemia. In prepubertal girls, the most common etiologies of androgen excess are premature adrenarche (60%) and congenital adrenal hyperplasia (CAH; 4%). In pubertal girls, polycystic ovary syndrome (PCOS; 20-40%) and CAH (14%) are the most common diagnoses related to androgen excess. Androgen-secreting ovarian or adrenal tumors are rare (0.2%). Early pubic hair, acne, and/or hirsutism are the most common clinical manifestations, but signs of overt virilization in adolescent girls-rapid progression of pubic hair or hirsutism, clitoromegaly, voice deepening, severe cystic acne, growth acceleration, increased muscle mass, and bone age advancement past height age-should prompt detailed evaluation. This article addresses the clinical manifestations of and management considerations for non-PCOS-related hyperandrogenism in adolescent girls. We propose an algorithm to aid diagnostic evaluation of androgen excess in this specific patient population.

Congenital Adrenal Hyperplasia-Current Insights in Pathophysiology, Diagnostics, and Management

Congenital adrenal hyperplasia (CAH) is a group of autosomal recessive disorders affecting cortisol biosynthesis. Reduced activity of an enzyme required for cortisol production leads to chronic overstimulation of the adrenal cortex and accumulation of precursors proximal to the blocked enzymatic step. The most common form of CAH is caused by steroid 21-hydroxylase deficiency due to mutations in CYP21A2. Since the last publication summarizing CAH in Endocrine Reviews in 2000, there have been numerous new developments. These include more detailed understanding of steroidogenic pathways, refinements in neonatal screening, improved diagnostic measurements utilizing chromatography and mass spectrometry coupled with steroid profiling, and improved genotyping methods. Clinical trials of alternative medications and modes of delivery have been recently completed or are under way. Genetic and cell-based treatments are being explored. A large body of data concerning long-term outcomes in patients affected by CAH, including psychosexual well-being, has been enhanced by the establishment of disease registries. This review provides the reader with current insights in CAH with special attention to these new developments.

The way toward adulthood for females with nonclassic congenital adrenal hyperplasia

Females with NC21OHD may present as asymptomatic or develop a wide range of androgen excess expression. Clinical manifestations may become evident in childhood and adolescence and include premature pubarche, precocious puberty, acne, hirsutism, and menstrual disorders or present later in life as oligo-ovulation and infertility. Glucocorticoids have been the mainstay of treatment as they regulate excess androgen expression by dampening ACTH activation. Their use requires a careful dose monitoring to avoid overtreatment and subsequently the risk of obesity, type 2 diabetes, dyslipidemia, hypertension, and osteoporosis. Women with NC21OHD need regular follow up throughout their life in order to overcome the physical and psychological burden of hyperandrogenism.

Clinical outcomes in 21-hydroxylase deficiency

PURPOSE OF REVIEW

The introduction of synthetic glucocorticoids 70 years ago made survival possible in classic 21-hydroxylase deficiency (21OHD). The currently used glucocorticoid therapy may lead to unphysiological dosing with negative consequencies on health in addition to the problems that may arise due to androgen over-exposure.

RECENT FINDINGS

Fertility in females with 21OHD seemed to be impaired, especially in the salt-wasting (SW) phenotype but when pregnancies did occur there was a higher risk for gestational diabetes and cesearean section. Increased fat mass, body mass index, insulin resistance and frequency of autoimmune disorders as well as impaired echocardiographic parameters and lower bone mineral density were found in 21OHD compared to controls. Negative effects on cognitive functions have been identified. Adrenal tumors, especially myelolipomas, were prevalent. Increased knowledge on steroid metabolism in 21OHD and urine steroid profiling may improve assessment of treatment efficacy. Nevanimibe, abiraterone acetate and anastrozole may have a place in the future management of 21OHD. Long-acting glucocorticoids may be a less favorable, especially dexamethasone.

SUMMARY

The various clinical outcomes need regular monitoring. Negative consequencies are to large extent the result of the unphysiological glucocorticoid replacement. Modern management with improved follow-up and future addition of new drugs may improve outcomes.