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Bone health should be an important concern in the care of patients affected by 21 hydroxylase deficiency.

ABSTRACT: Osteoporosis has been an understandable concern for children and adult patients with congenital adrenal hyperplasia (CAH) who may receive or have received supraphysiological doses of glucocorticoids. Some previous reports on bone mineral density (BMD) in adult CAH patients showed no significant differences in BMD between patients with CAH and controls, but others have found lower BMD in CAH patients. In reports documenting the BMD reduction, this outcome has been attributed to an accumulated effect of prolonged exposure to excess glucocorticoids during infancy and childhood. We recently conducted a trial to establish the role of the total cumulative glucocorticoid dose on BMD. We established for the first time that there was a negative relationship between total cumulative glucocorticoid dose and lumbar and femoral BMD. Women might benefit from the preserving effect of estrogens compared to men. BMI (Body Mass Index) also appeared to protect patients from bone loss. In light of this, physicians should bear in mind the potential consequences of glucocorticoids on bone and therefore adjust the treatment and improve clinical and biological surveillance from infancy. Furthermore, preventive measures against corticosteroid-induced osteoporosis should be discussed right from the beginning of glucocorticoid therapy.

SUBMITTER: Bachelot A

PROVIDER: S-EPMC2948879 | biostudies-literature | 2010

REPOSITORIES: biostudies-literature

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Bone health should be an important concern in the care of patients affected by 21 hydroxylase deficiency.

Bachelot Anne A Chakhtoura Zeina Z Samara-Boustani Dinane D Dulon Jérome J Touraine Philippe P Polak Michel M

International journal of pediatric endocrinology 20100928

Osteoporosis has been an understandable concern for children and adult patients with congenital adrenal hyperplasia (CAH) who may receive or have received supraphysiological doses of glucocorticoids. Some previous reports on bone mineral density (BMD) in adult CAH patients showed no significant differences in BMD between patients with CAH and controls, but others have found lower BMD in CAH patients. In reports documenting the BMD reduction, this outcome has been attributed to an accumulated eff ...[more]

PMID: 20936142

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Project description:Congenital adrenal hyperplasia due to 21-hydroxylase deficiency is caused by deletions, large gene conversions or mutations in CYP21A2 gene. The human gene is located at 6p21.3 within a locus containing the genes for putative serine/threonine Kinase RP, complement C4, steroid 21-hydroxylase CYP21 tenascin TNX, normally, in a duplicated cluster known as RCCX module. The CYP21 extra copy is a pseudogene (CYP21A1P). In Brazil, 30-kb deletion forming monomodular alleles that carry chimeric CYP21A1P/A2 genes corresponds to ~9% of disease-causing alleles. Such alleles are considered to result from unequal crossovers within the bimodular C4/CYP21 locus. Depending on the localization of recombination breakpoint, different alleles can be generated conferring the locus high degree of allelic variability. The purpose of the study was to investigate the variability of deleted alleles in patients with 21-hydroxylase deficiency.We used different techniques to investigate the variability of 30-kb deletion alleles in patients with 21-hydroxylase deficiency. Alleles were first selected after Southern blotting. The composition of CYP21A1P/A2 chimeric genes was investigated by ASO-PCR and MLPA analyses followed by sequencing to refine the location of recombination breakpoints. Twenty patients carrying at least one allele with C4/CYP21 30-kb deletion were included in the study.An allele carrying a CYP21A1P/A2 chimeric gene was found unusually associated to a C4B/C4A Taq I 6.4-kb fragment, generally associated to C4B and CYP21A1P deletions. A novel haplotype bearing both p.P34L and p.H62L, novel and rare mutations, respectively, was identified in exon 1, however p.P30L, the most frequent pseudogene-derived mutation in this exon, was absent. Four unrelated patients showed this haplotype. Absence of p.P34L in CYP21A1P of normal controls indicated that it is not derived from pseudogene. In addition, the combination of different approaches revealed nine haplotypes for deleted 21-hydroxylase deficiency alleles.This study demonstrated high allelic variability for 30-kb deletion in patients with 21-hydroxylase deficiency indicating that a founder effect might be improbable for most monomodular alleles carrying CYP21A1P/A2 chimeric genes in Brazil.

Project description:Phenylalanine hydroxylase (PAH) deficiency is a genetic disorder characterized by deficiency of the PAH enzyme. Patients follow a phenylalanine-restricted diet low in intact protein, and must consume synthetic medical food (MF) to supply phenylalanine-free protein. We assessed relationships between dietary intake and nutrient source (food or MF) on bone mineral density (BMD) and bone turnover markers (BTM) in PAH deficiency. Blood from 44 fasted females 11-52 years of age was analyzed for plasma phenylalanine, serum BTM [CTx (resorption), P1NP (formation)], vitamin D, and parathyroid hormone (PTH). BTM ratios were calculated to assess resorption relative to formation (CTx/P1NP). Dual energy X-ray absorptiometry measured total BMD and age-matched Z-scores. Three-day food records were analyzed for total nutrient intake, nutrients by source (food, MF), and compliance with MF prescription. Spearman's partial coefficients (adjusted for age, BMI, energy intake, blood phenylalanine) assessed correlations. All had normal BMD for age (Z-score >-2). Sixty-four percent had high resorption and normal formation indicating uncoupled bone turnover. CTx/P1NP was positively associated with food phenylalanine (r 2 = 0.39; p-value = 0.017), energy (r 2 = 0.41; p-value = 0.011) and zinc (r 2 = 0.41; p-value = 0.014). CTx/P1NP was negatively associated with MF fat (r 2 = -0.44; p-value = 0.008), MF compliance (r 2 = -0.34; p-value = 0.056), and positively with food sodium (r 2 = 0.43; p-value = 0.014). CTx/P1NP decreased significantly with age (p-value = 0.002) and higher PTH (p-value = 0.0002). Phenylalanine was not correlated with any bone indicator. Females with PAH deficiency had normal BMD but elevated BTM, particularly resorption. More favorable ratios were associated with nutrients from MF and compliance. Younger females had less favorable BTM ratios. Promoting micronutrient intake through compliance with MF may impact bone metabolism in patients with PAH deficiency.SynopsisBone mineral density was normal in 44 females with PAH deficiency; however, bone turnover markers suggested uncoupling of bone resorption and formation, particularly in younger patients. Adequate nutrient intake from medical food and overall medical food compliance may positively impact bone turnover.

Project description:BACKGROUND:Chimeric CYP21A1P/CYP21A2 genes, caused by homologous recombination between CYP21A2 (cytochrome P450, family 21, subfamily A, polypeptide 2) and its highly homologous pseudogene CYP21A1P (cytochrome P450, family 21, subfamily A, polypeptide 1 pseudogene), are common in patients with congenital adrenal hyperplasia (CAH) due to 21-hydroxylase deficiency (21-OHD). A comprehensive junction site analysis of chimeric CYP21A1P/CYP21A2 genes is needed for optimizing genetic analysis strategy and determining clinical relevance. METHODS:We conducted a comprehensive genetic analysis of chimeric CYP21A1P/CYP21A2 genes in a cohort of 202 unrelated 21-OHD patients. Targeted CYP21A2 mutation analysis was performed, and genotyping of chimeric CYP21A1P/CYP21A2 genes was cross-confirmed with Southern blot, RFLP, and multiplex ligation-dependent probe amplification analyses. Junction sites of chimera genes were determined by sequencing the long-PCR products amplified with primers CYP779f and Tena32F. An updated bioinformatics survey of Chi-like sequences was also performed. RESULTS:Of 100 probands with a chimeric allele, 96 had a chimera associated with the severe classic salt-wasting form of CAH, and the remaining 4 carried an uncommon attenuated chimera with junction sites upstream of In2G (c.293-13A/C>G), which is associated with a milder phenotype. In addition to 6 of 7 reported chimeras, we identified a novel classic chimera (CH-8) and a novel attenuated chimera (CH-9). Attenuated chimeras explained prior genotype-phenotype discrepancies in 3 of the patients. Sequencing the CYP779f/Tena32F amplicons accurately differentiated between classic and attenuated chimeras. The bioinformatics survey revealed enrichment of Chi-like sequences within or in the vicinity of intron 2. CONCLUSIONS:Junction site analysis can explain some genotype-phenotype discrepancies. Sequencing the well-established CYP779f/Tena32F amplicons is an unequivocal strategy for detecting attenuated chimeric CYP21A1P/CYP21A2 genes, which are clinically relevant.

Project description:ContextChronic supraphysiological glucocorticoid therapy controls the androgen excess of 21-hydroxylase deficiency (21OHD) but contributes to the high prevalence of obesity, glucose intolerance, and reduced bone mass in these patients. Abiraterone acetate (AA) is a prodrug for abiraterone, a potent CYP17A1 inhibitor used to suppress androgens in the treatment of prostate cancer.ObjectiveThe objective of the study was to test the hypothesis that AA added to physiological hydrocortisone and 9α-fludrocortisone acetate corrects androgen excess in women with 21OHD without causing hypertension or hypokalemia.DesignThis was a phase 1 dose-escalation study.SettingThe study was conducted at university clinical research centers.ParticipantsWe screened 14 women with classic 21OHD taking hydrocortisone 12.5-20 mg/d to enroll six participants with serum androstenedione greater than 345 ng/dL (>12 nmol/L).InterventionAA was administered for 6 days at 100 or 250 mg every morning with 20 mg/d hydrocortisone and 9α-fludrocortisone acetate.Main outcome measureThe primary endpoint was normalization of mean predose androstenedione on days 6 and 7 (< 230 ng/dL [<8 nmol/L)] in greater than 80% of participants. Secondary end points included serum 17-hydroxyprogesterone and testosterone (T), electrolytes, plasma renin activity, and urine androsterone and etiocholanolone glucuronides.ResultsWith 100 mg/d AA, mean predose androstenedione fell from 764 to 254 ng/dL (26.7-8.9 nmol/L). At 250 mg/d AA, mean androstenedione normalized in five participants (83%) and decreased from 664 to 126 ng/dL (23.2-4.4 nmol/L), meeting the primary end point. Mean androstenedione declined further during day 6 to 66 and 38 ng/dL (2.3 and 1.3 nmol/L) at 100 and 250 mg/d, respectively. Serum T and urinary metabolites declined similarly. Abiraterone exposure was strongly negatively correlated with mean androstenedione. Hypertension and hypokalemia were not observed.ConclusionAA 100-250 mg/d added to replacement hydrocortisone normalized several measures of androgen excess in women with classic 21OHD and elevated serum androstenedione.

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Bone health should be an important concern in the care of patients affected by 21 hydroxylase deficiency.

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Bone health should be an important concern in the care of patients affected by 21 hydroxylase deficiency.

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