IMAGe and Related Undergrowth Syndromes: The Complex Spectrum of Gain-of-Function CDKN1C Mutations.

CDKN1C is a cyclin-dependent kinase Inhibitor and negative regulator of cellular proliferation. Recently, gain-of-function mutations in the PCNA domain of CDKN1C have been reported as the genetic basis of various growth-retarded syndromes including IMAGe syndrome, Russell Silver syndrome as well as a novel undergrowth syndrome that additionally exhibited early adulthood onset diabetes. This review summarizes the key clinical features and the molecular advances that have contributed to our understanding of this complex phenotypic spectrum.

Latent Adrenal Insufficiency: From Concept to Diagnosis.

Primary adrenal insufficiency (PAI) is a rare disease and potentially fatal if unrecognized. It is characterized by destruction of the adrenal cortex, most frequently of autoimmune origin, resulting in glucocorticoid, mineralocorticoid, and adrenal androgen deficiencies. Initial signs and symptoms can be nonspecific, contributing to late diagnosis. Loss of zona glomerulosa function may precede zona fasciculata and reticularis deficiencies. Patients present with hallmark manifestations including fatigue, weight loss, abdominal pain, melanoderma, hypotension, salt craving, hyponatremia, hyperkalemia, or acute adrenal crisis. Diagnosis is established by unequivocally low morning serum cortisol/aldosterone and elevated ACTH and renin concentrations. A standard dose (250 µg) Cosyntropin stimulation test may be needed to confirm adrenal insufficiency (AI) in partial deficiencies. Glucocorticoid and mineralocorticoid substitution is the hallmark of treatment, alongside patient education regarding dose adjustments in periods of stress and prevention of acute adrenal crisis. Recent studies identified partial residual adrenocortical function in patients with AI and rare cases have recuperated normal hormonal function. Modulating therapies using rituximab or ACTH injections are in early stages of investigation hoping it could maintain glucocorticoid residual function and delay complete destruction of adrenal cortex.

News about the genetics of congenital primary adrenal insufficiency.

Primary adrenal insufficiency (PAI) is characterized by impaired production of steroid hormones due to an adrenal cortex defect. This condition incurs a risk of acute insufficiency which may be life-threatening. Today, 80% of pediatric forms of PAI have a genetic origin but 5% have no clear genetic support. Recently discovered mutations in genes relating to oxidative stress have opened the way to research on genes unrelated to the adrenal gland. Identification of causal mutations in a gene responsible for PAI allows genetic counseling, guidance of follow-up and prevention of complications. This is particularly true for stress oxidative anomalies, as extra-adrenal manifestations may occur due to the sensitivity to oxidative stress of other organs such as the heart, thyroid, liver, kidney and pancreas.

Is Diagnosis and Subclassification of Adrenal Insufficiency as Easy as It Looks?

The diagnosis of adrenal insufficiency (AI) is a challenge. Most signs and symptoms are nonspecific and vary considerably depending upon the underlying cause and degree of AI. Identification of AI is crucial because the disease may be life-threatening if left unrecognized. The diagnostic evaluation consists of three steps. The first step is establishing the presence of hypocortisolism. The second step is establishing the level of hypothalamus-pituitary-adrenal axis dysfunction. The third and final step is searching for the exact cause of AI by additional laboratory and imaging techniques. Each diagnostic step can have its own uncertainties. The optimal test in case of intermediate basal cortisol measurements is still a matter of debate. Furthermore, interpretation of the results of the tests is complicated by arbitrary definitions of normal cutoff responses, variability in the analytical accuracy of the cortisol assays used and factors influencing cortisol-binding globulin. This chapter aims to provide a concise stepwise approach for the diagnostic evaluation of AI, taking into account the possible pitfalls associated with the different tests.

[Adrenal insufficiency and treatment with glucocorticosteroid]. / Binyreinsufficiens og behandling med glukokortikosteroid

Lately, it has been revealed that cortisol (hydrocortisone) secretion is lower than previously thought. Replacement doses of 10-15 mg/24 h seem sufficient in non-obese individuals. The day-night variation and in particular the fast oscillations in plasma cortisol concentration may be important for the patient's well-being. The lack of these fluctuations may explain why quality of life in some patients is unsatisfactory despite seemingly adequate substitution. It has been assumed that critical disease and stress such as major surgery require increased doses of hydrocortisone. Recently, this notion has been questioned, and in many patients with serious diseases the amount of hydrocortisone secreted is not increased. At present, there is no documentation for the benefit of high doses (100-400 mg hydrocortisone) in patients with critical disease and adrenal insufficiency.

Primary adrenal insufficiency in children: twenty years experience at the Sainte-Justine Hospital, Montreal.

Primary adrenal insufficiency (PAI) in the pediatric population (0-18 yr) is most commonly attributed to congenital adrenal hyperplasia (CAH), which occurs in about 1 in 15,000 births, followed by Addison's disease, with an assumed autoimmune etiology. However, molecular advances have increased the number of possible diagnoses. The objective of this study was to determine the incidence and etiologies of PAI in our pediatric population. All patients with a diagnosis of PAI followed by the Endocrinology Service at our institution between September 1981 and September 2001 were studied. One hundred three patients (48 boys) were identified, primarily by the Endocrinology Clinic case registry. CAH was the most frequent etiology (71.8%). However, non-CAH etiologies accounted for 28.2%, of which 55% were nonautoimmune in etiology. Importantly, the CAH sex ratio was 1:1, despite the absence of biochemical screening for this condition in Quebec newborns. Patients with autoimmune polyendocrinopathy-candidiasis-ectodermal dysplasia (APECED) developed adrenal insufficiency 4 yr earlier than those with non-autoimmune disease. Finally, we review the rare etiologies of PAI and propose an algorithm to aid in targeted genetic testing.

[Hyporeninemic hypoaldosteronism. Case report and attempt at pathophysiological classification (author's transl)]. / Hipoaldosteronismo hiporreninémico. Presentación de un caso e intento de clasificación fisiopatológica.

A 75 year-old male presented with hyperkalemia unexplained by a moderate renal insufficiency, low basal levels of aldosterone and renin with a subnormal response to walking and saline depletion, and normal glucocorticoid function. The hyperkalemia was corrected by fluorocortisone administration. The concept of hypoaldosteronism is reviewed, defining it as an isolated aldosterone deficiency and thus excluding the combined deficiency of cortisol and aldosterone and the suprarenal enzyme deficits that simultaneously involve mineralocorticoid and glucocorticoid synthesis. Depending on the presence or absence of alterations of the renin-angiotensin axis, this infrequent syndrome can be pathophysiologically classified as low, normal or high renin hypoaldosteronism. The characteristic features of each type are described, and emphasis is made on the need for a high index of suspicion when unexplained hyperkalemia is present in order to perform the appropriate tests to confirm or rule out hypoaldosteronism.

Relative adrenal insufficiency.

PURPOSE OF REVIEW: This article will review the clinical presentation, diagnosis, and treatment of acute adrenal insufficiency and explore the concept of 'relative adrenal insufficiency' in the critically ill. RECENT FINDINGS: Current dogma suggests that as many as 70% of patients in intensive care units with the clinical syndromes of sepsis or cardiogenic shock have 'relative adrenal insufficiency'. This article will explore how this concept came into being and why the concept has no clinical utility. SUMMARY: This article will provide an approach to critically ill patients that will identify adrenal insufficiency when it is part of the pathophysiology of a given patient and, at the same time, prevent the unnecessary treatment of critically ill patients with high doses of glucocorticoids for 'stress' when adrenal insufficiency is not a factor in the illness.

Evaluation of random plasma cortisol and the low dose corticotropin test as indicators of adrenal secretory capacity in critically ill patients: a prospective study.

It is unclear whether a random plasma cortisol measurement and the corticotropin (ACTH) test adequately reflect glucocorticoid secretory capacity in critical illness. This study aimed to determine whether these tests provide information representative of the 24 hour period. Plasma cortisol was measured hourly for 24 hours in 21 critically ill septic patients followed by a corticotropin test with 1 microg dose administered intravenously. Serum and urine were analysed for ACTH and free cortisol respectively. Marked hourly variability in plasma cortisol was evident (coefficient of variation 8-30%) with no demonstrable circadian rhythm. The individual mean plasma cortisol concentrations ranged from 286 +/- 59 nmol/l to 796 +/- 83 nmol/l. The 24 hour mean plasma cortisol was strongly correlated with both random plasma cortisol (r2 0.9, P < 0.0001) and the cortisol response to corticotropin (r2 0.72, P < 0.001). Only nine percent of patients increased their plasma cortisol by 250 nmol/l after corticotropin (euadrenal response). However, 35% of non-responders had spontaneous hourly rises > 250 nmol/l thus highlighting the limitations of a single point corticotropin test. Urinary free cortisol was elevated (865 +/- 937 nmol) in both corticotropin responders and non-responders suggesting elevated plasma free cortisol. No significant relationship was demonstrable between plasma cortisol and ACTH. We conclude that although random cortisol measurements and the low dose corticotropin tests reliably reflect the 24 hour mean cortisol in critical illness, they do not take into account the pulsatile nature of cortisol secretion. Consequently, there is the potential for erroneous conclusions about adrenal function based on a single measurement. We suggest that caution be exercised when drawing conclusions on the adequacy of adrenal function based on a single random plasma cortisol or the corticotropin test.

Emergencia pediátrica: insuficiencia suprarrenal aguda / Pediatric emergency: adrenal insufficiency and adrenal crisis

La insuficiencia suprarrenal aguda es un cuadro originado por deficiencia mineralocorticoidea o glucocorticoidea, cuyo no diagnóstico y adecuado tratamiento lleva a una emergenciagrave con riesgo para la vida del paciente. Se clasifica en insuficiencia suprarrenal primaria, que presenta en general compromiso glucocorticoideo y mineralocorticoideo, y secundaria,sin deficiencia mineralocorticoidea. Los pacientes pueden no presentar síntomas que alerten precozmente, comoanorexia, náuseas, astenia, vómitos y dolor abdominal. De no corregirse, aparecen hipotensión, hipoglucemia, hiponatremia con hipercaliemia, deshidratación y shock. Es indispensable,aun en caso de duda, corregir la hipovolemia, el desequilibrioelectrolítico y la hipoglucemia, y administrar glucocorticoidesa dosis de estrés. Superada la fase aguda, administrar la dosis de corticoides de mantenimiento y, en caso necesario, añadir mineralocorticoides.

Emergencia pediátrica: insuficiencia suprarrenal aguda / Pediatric emergency: adrenal insufficiency and adrenal crisis

La insuficiencia suprarrenal aguda es un cuadro originado por deficiencia mineralocorticoidea o glucocorticoidea, cuyo no diagnóstico y adecuado tratamiento lleva a una emergenciagrave con riesgo para la vida del paciente. Se clasifica en insuficiencia suprarrenal primaria, que presenta en general compromiso glucocorticoideo y mineralocorticoideo, y secundaria,sin deficiencia mineralocorticoidea. Los pacientes pueden no presentar síntomas que alerten precozmente, comoanorexia, náuseas, astenia, vómitos y dolor abdominal. De no corregirse, aparecen hipotensión, hipoglucemia, hiponatremia con hipercaliemia, deshidratación y shock. Es indispensable,aun en caso de duda, corregir la hipovolemia, el desequilibrioelectrolítico y la hipoglucemia, y administrar glucocorticoidesa dosis de estrés. Superada la fase aguda, administrar la dosis de corticoides de mantenimiento y, en caso necesario, añadir mineralocorticoides.(AU)

Metyrapone test with adrenocorticotrophic levels. Separating primary from secondary adrenal insufficiency.

Basal plasma adrenocorticotrophic hormone (ACTH) and cortisol concentrations as well as plasma ACTH and 11-deoxycortisol responses to the administration of a single dose of metyrapone were evaluated in 104 patients with intact pituitary-adrenal axis, in 20 patients with secondary adrenal insufficiency, and in seven patients with primary adrenal insufficiency. In patients with primary adrenal insufficiency, baseline ACTH levels were high. Following metyrapone administration, 11-deoxycortisol concentrations were low and ACTH levels did not change. In patients with secondary adrenal insufficiency, baseline plasma ACTH levels were normal, but neither 11-deoxycortisol nor ACTH levels increased in response to metyrapone. The metyrapone test is not only useful to screen for adrenal insufficiency, it is also useful to differentiate a primary from a secondary cause.

NIH conference. Clinical applications of corticotropin-releasing factor.

Ovine and human corticotropin-releasing factors (CRF) have similar potencies in causing adrenocorticotropic hormone (ACTH) and cortisol secretion in normal humans. Using long-acting ovine CRF (1 microgram/kg body weight as an intravenous bolus), we tested patients with Cushing's syndrome, adrenal insufficiency, and psychiatric conditions with mild hypercortisolism. Over 95% of hypercortisolemic patients with a pituitary adenoma responded with increases in plasma ACTH and cortisol concentrations; patients with the ectopic ACTH syndrome had no ACTH or cortisol responses; patients with ACTH-independent hypercortisolism of adrenal origin had low or undetectable plasma ACTH concentrations before and after CRF without any cortisol response. The differences in responses of patients with adrenal insufficiency of primary, pituitary, or suprapituitary type likewise suggest value of the CFR test in their differential diagnosis. The responses in the psychiatric patients should permit differentiation between Cushing's syndrome and hypercortisolism of psychiatric origin.