Congenital Adrenal Hyperplasia

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.

Insulin Resistance in Congenital Adrenal Hyperplasia is Compensated for by Reduced Insulin Clearance

CONTEXT

Congenital adrenal hyperplasia (CAH) patients have potential normal longevity. However, a greater risk for cardiovascular disease has been reported. Insulin resistance and hyperinsulinemia have been described in CAH patients, whereas the prevalence of overt type 2 diabetes is not higher in CAH than in normal population.

OBJECTIVE

To examine the contributions of insulin secretion and of hepatic insulin clearance to compensatory hyperinsulinemia in young insulin-resistant adults with classic CAH due to 21-hydroxylase deficiency (21-OHD).

DESIGN

Cross-sectional.

SETTING

University outpatient clinics.

METHODS

Fifty-one participants: 21 controls, and 30 CAH (15 virilizing and 15 salt-wasting phenotypes), female/male (33/18), age (mean [SD]): 24.0 (3.6) years, body mass index: 24.6 (4.9)kg/m2 with normal glucose tolerance, were submitted to a hyperglycemic clamp study.

MAIN OUTCOME MEASURES

Insulin sensitivity, beta cell function, and hepatic insulin clearance using appropriate modeling.

RESULTS

We found an increased insulin resistance in 21-OHD. The systemic hyperinsulinemia (posthepatic insulin delivery) was elevated in CAH patients. No increases were observed in insulin secretory rate (beta cell function) in the first phase or during the hyperglycemic clamp. The increase in insulin concentrations was totally due to a ~33% reduction in insulin clearance.

CONCLUSION

21-OHD nonobese subjects have reduced insulin sensitivity and beta cell response unable to compensate for the insulin resistance, probably due to overexposure to glucocorticoids. Compensatory hyperinsulinemia is most related with reduced hepatic insulin clearance. The exclusive adaptation of the liver acts as a gating mechanism to regulate the access of insulin to insulin-sensitive tissues to maintain glucose homeostasis.

Assisted Reproduction in Congenital Adrenal Hyperplasia

Congenital Adrenal Hyperplasia (CAH) is a group of autosomal recessive disorders characterized by defects of adrenal steroidogenesis due to mutations in one of the following enzymes: 21-hydroxylase (21OH), 11β-hydroxylase (11βOH), 17α-hydroxylase (17OH; also known as 17, 20-lyase), 3β hydroxysteroid dehydrogenase type 2 (3βHSD2), steroidogenic acute regulatory protein (StAR), P450 cholesterol side-chain cleavage (P450scc), and P450 oxidoreductase (POR). More than 95% of congenital adrenal hyperplasia cases are due to mutations in CYP21A2, the gene encoding the adrenal steroid 21-hydroxylase enzyme (P450c21). This work focuses on this type of CAH given that it is the most frequent one. This disease is characterized by impaired cortisol and aldosterone production as well as androgen excess. A variant of the CAH is the non-classic type of CAH (NCCAH), usually asymptomatic before the 5th year of age, diagnosed during puberty especially in patients visiting a fertility clinic. NCCAH is characterized mainly by anovulatory cycles and/or high androgen concentrations. Both types of CAH are associated with infertility. Given that the incidence of NCCAH is greater than that of CAH, patients suffering from NCCAH are more often diagnosed for the first time in a fertility clinic. Thus, screening for NCCAH should always be considered. The causes of infertility in CAH patients are multi-factorial including virilization of external genitalia, altered psychosocial development, and hormonal disorders. The main challenges encountered in assisted reproduction are the androgen excess-associated anovulatory cycles as well as the increased circulating progesterone concentrations during the follicular phase which impact endometrial receptivity, tubal motility, and cervical thickness. Administration of sufficient substitution dose of glucocorticoids usually resolves these problems and leads not only to successful assisted reproduction treatment but also to spontaneous pregnancy. Patients with CAH should be followed by a multidisciplinary team including gynecologist, endocrinologist, and pediatrician.

Cognitive abilities in women with complete androgen insensitivity syndrome and women with gonadal dysgenesis

BACKGROUND

Many questions regarding the mechanisms behind sex differences in cognitive abilities are still unanswered. On a group level, men typically outperform women on certain spatial tasks, whereas women perform better on certain tests of memory and verbal ability. The prevailing theories concerning the biological predispositions for these and other differences in behaviour and brain function focus on early and prolonged exposure to sex hormones. There is, however, evidence of direct effects of sex chromosomes on sex-typical behaviour in other species.

OBJECTIVES

To study the influence of sex hormones and sex chromosomes on cognition in women with Complete androgen insensitivity (CAIS) and Gonadal dysgenesis (GD).

METHODS

Eighteen women with CAIS, 6 women with 46,XYGD, and 7 women with 46,XXGD were compared with age-matched male and female controls on tests of spatial and verbal abilities, memory functions, and emotion recognition.

RESULTS

Women with CAIS, XYGD, and XXGD performed similar to female controls on cognitive tasks. However, on a test of emotion recognition, women with XXGD outperformed the other groups, whereas women with CAIS and XYGD performed similar to male controls.

CONCLUSION

Our results support theories of androgen effects on cognitive abilities and suggest that factors related to sex chromosomes may influence emotion recognition. Implications of an atypical sex hormone situation and sex chromosome variation are discussed.

Miscarriages in families with an offspring that have classic congenital adrenal hyperplasia and 21-hydroxylase deficiency

BACKGROUND

The most common form of congenital adrenal hyperplasia is 21-hydroxylase deficiency (CAH). Both men and women with classic CAH have lower fertility rates than the general population, and an increased rate of miscarriages has been reported in affected women. There are no data on the incidence rate of miscarriages in families with an offspring that have classic CAH.

METHODS

We studied families with a history of classic CAH. The families came from different parts of Germany and attended the annual meeting of the German CAH support group for parents and patients which was held in Hamburg in September 2014. The data was collected anonymously by a paper-based questionnaire which was completed by the families at home. The families also accepted the responsibility to address this question to their siblings. In all, the data of 50 families with at least one child with classic CAH, and the data of 164 parental siblings were available for evaluation. Miscarriage rates were calculated in relation to the reported pregnancies.

RESULTS

Twenty-two miscarriages were reported from 19 families. At least one miscarriage occurred in 38% of the families, three families experienced two miscarriages and 16 families had one miscarriage each. The mean miscarriage rate was 15.8%. The heterozygous mothers had a total of 90 siblings (41 m, 49 f), while 74 siblings (33 m, 41 f) were reported from the heterozygous fathers. The miscarriage rate was 10.1% in the families of the mothers` siblings, and 11.4% in the families of the fathers` siblings. The genotype was known in all parents that have an offspring with classic CAH, but not defined in 82% of the maternal siblings, and in 86% of the paternal siblings. No child with classic CAH has been diagnosed in any of the sibling's families to date.

CONCLUSION

Our data show that the miscarriage rate in German families with a child with classic CAH is not elevated.

Endocrine Hypertension: A Practical Approach

Elevated blood pressure resulting from few endocrine disorders (endocrine hypertension) accounts for a high proportion of cases of secondary hypertension. Although some features may be suggestive, many cases of endocrine hypertension remain silent until worked up for the disease. A majority of cases result from primary aldosteronism. Other conditions that can cause endocrine hypertension are: congenital adrenal hyperplasia, Liddle syndrome, pheochromocytomas, Cushing's syndrome, acromegaly, thyroid diseases, primary hyperparathyroidism and iatrogenic hormone manipulation. Early identification and treatment of the cause of endocrine hypertension may help to reduce morbidity and mortality related to these disorders. This article gives a comprehensive and practical approach to the diagnosis and management of endocrine hypertension.

High 17-hydroxyprogesterone level in newborn screening test for congenital adrenal hyperplasia

We report a case of a female infant with an elevated 17-hydroxyprogesterone level detected in the newborn screening for 21-hydroxylase deficiency, the most common cause of congenital adrenal hyperplasia. The physical examination was unremarkable including no dysmorphism and no signs of virilisation. In the absence of clinical evidence of androgen excess, as would be expected in a female infant with 21-hydroxylase deficiency, further evaluation was performed and led to the diagnosis of the extremely rare disorder, 3β-hydroxysteroid dehydrogenase deficiency. This case highlights the differential diagnosis of elevated 17-hydroxyprogesterone levels in newborn screening and the importance of correct diagnosis for improving patient care.

Molecular mechanisms associated with 46,XX disorders of sex development

In the female gonad, distinct signalling pathways activate ovarian differentiation while repressing the formation of testes. Human disorders of sex development (DSDs), such as 46,XX DSDs, can arise when this signalling is aberrant. Here we review the current understanding of the genetic mechanisms that control gonadal development, with particular emphasis on those that drive or inhibit ovarian differentiation. We discuss how disruption to these molecular pathways can lead to 46,XX disorders of ovarian development. Finally, we look at recently characterized novel genes and pathways that contribute and speculate how advances in technology will aid in further characterization of normal and disrupted human ovarian development.