Variable ACTH-stimulated 17-hydroxyprogesterone values in 21-hydroxylase deficiency carriers are not related to the different CYP21 gene mutations.

The currently used cutoff level for ACTH-stimulated 17- hydroxyprogesterone (17OHP) for the diagnosis of the nonclassical (NC) form of 21-hydroxylase deficiency (21OHD), established before molecular studies, is based on the mean + 2 SD of 17OHP levels of obligate heterozygotes. However, carriers of CYP21 mutations present variable ACTH-stimulated 17OHP levels, ranging from normal values up to 30 nmol/liter. The aim of this study was to determine whether ACTH-stimulated 17OHP levels in obligate carriers for 21OHD would be correlated with the impairment of the enzyme activity caused by these mutations, which would affect the 17OHP cutoff level for the diagnosis of the NC form. Fifty-nine parents of patients with the classical and NC forms of 21OHD had their DNA screened for the mutations found in the index case and were divided into three mutation groups according to the impairment of enzyme activity (A = 0%, B = 3%, and C > 20%). All parents carried mutations in one allele (29 of group A, 9 of group B, and 21 of group C). Blood samples were collected at baseline condition and 60 min after ACTH (250 microg i.v.) to measure 17OHP levels. The levels among groups A, B, and C were compared using the Kruskall Wallis test. ACTH-stimulated 17OHP levels identified 39% of the carriers (9 in group A, 2 in group B and 12 in group C). The mean +/- SD basal 17OHP levels in groups A, B, and C were: 2.94 +/- 1.89, 1.77 +/- 0.81 and 3.90 +/- 2.43 nmol/liter, respectively (P > 0.05) and for ACTH-stimulated levels were 12.6 +/- 7.2, 13.2 +/- 12.9 and 16.8 +/- 7.8 nmol/liter, respectively (P > 0.05). Two carriers presented ACTH-stimulated 17OHP levels between 30 and 45 nmol/liter and their entire CYP21 sequencing revealed only one mutation in heterozygous state indicating that the current cutoff level might overestimate the diagnosis of the NC form. We conclude that the variable ACTH-stimulated 17-OHP levels in carriers are not related to CYP21 gene mutations with different impairment of enzyme activity.

Tratamento da hiperplasia supra-renal congênita por deficiência da 21-hidroxilase / Treatment of congenital adrenal hyperplasia by 21-hydroxylase deficiency

O tratmento da hiperplasia supra-renal congênita por deficiência da 21-hidroxilase (HSRC-21 OH) tem como objetivos repor glico e mineralocorticóides, ecitar a virilizaçäo dos genitais externos, prevenir a desidratacao por perda de sal, controlar o hiperandrogenismo sem afetar a velocidade d crescimento, preservar a funçäo gonadal, fertilidade e estatura final. Relatamos a nossa experiência no acompanhamento de 96 pacientes com HSRC-21OH. nas crianças utilizamos como glicocorticóide o acetato de cortisona (18-20 mg/m2/dia) e nos adultos a dexametasona (0,25-0,75 mg/dia). quando necessário, a reposiçäo do mineralocorticóide foi feita com 9 alfa-fluor-hidrocortisona50-250µg/dia dependendo da faiza etária. Apesar da substiruiçäo adequadacom glico e/ou minerolocorticides o resultado final do tratamento da HSRC-21OH ainda deixa a desejar, principalmente em relaçäo ao crescimento, já que a estatura final na maior parte das caduísticas está entre -1 e -2 DP em relaçäo a estatura alvo. Novas terapêuticas da HSRC-21OH, como a associaçäo de hidrocortisona, fludocortisona , flutamida e tstolactona ou a supra rrenalectomia cirúrgica, ainda estäo em fase experimental e a evoluçäo a longo prazo é necessária para avaliar seu real efeito.