Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound

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Query: UMLS:C0235394 (wasting)
8,040 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

We have designed a rapid and convenient strategy to determine nine of the most common mutations in the 21-hydroxylase gene (CYP21). The frequency of the mutations was investigated in 34 Japanese patients affected with congenital adrenal hyperplasia (CAH) caused by 21-hydroxylase deficiency. We characterized 82% of the CAH chromosomes. The most frequent mutations were a C/A to G substitution in intron 2 in the salt-wasting form of the disease and an I172N in the simple virilizing form. Three de novo mutations were found. Two homozygous mutations (S268T and N493S) were detected by direct sequencing of all exons of CYP21 in two siblings, who had a normal genotype at all positions screened. We successfully applied these methods for prenatal diagnosis in one family. These procedures proved to be sensitive and rapid for the detection of the most common known mutations in the CYP21 gene and may be useful for genetic screening.
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PMID:Molecular analysis of Japanese patients with steroid 21-hydroxylase deficiency. 1049 74

Congenital adrenal hyperplasia (CAH) is a group of autosomal recessive disorders. CAH is most often caused by deficiency of steroid 21-hydroxylase. The frequency of CYP21-inactivating mutations and the genotype-phenotype relationship were characterized in 155 well defined unrelated CAH patients. We were able to elucidate 306 of 310 disease-causing alleles (diagnostic sensitivity, 98.7%). The most frequent mutation was the intron 2 splice site mutation (30.3%), followed by gene deletions (20.3%), the I172N mutation (19.7%) and large gene conversions (7.1%). Five point mutations were detected that have not been described in other CAH cohorts. Genotypes were categorized in 4 mutation groups (null, A, B, and C) according to their predicted functional consequences and compared to the clinical phenotype. The positive predictive value for null mutations (ppv(null)) was 100%, as all patients with these mutations had a salt-wasting phenotype. In mutation group A (intron 2 splice site mutation in homozygous or heterozygous form with a null mutation), the ppv(A) to manifest with salt-wasting CAH was 90%. In group B predicted to result in simple virilizing CAH (I172N in homozygous or compound heterozygous form with a more severe mutation), ppv(B) was 74%. In group C (P30L, V281L, P453S in homozygous or compound heterozygous form with a more severe mutation), ppv(C) was 64.7% to exhibit the nonclassical form of CAH, but 90% when excluding the P30L mutation. Thus, in general, a good genotype-phenotype relationship is shown in patients with either the severest or the mildest mutations. A considerable degree of divergence is observed within mutation groups of intermediate severity. As yet undefined factors modifying 21-hydroxylase gene expression and steroid hormone action are likely to account for these differences in phenotypic expression.
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PMID:Predicting phenotype in steroid 21-hydroxylase deficiency? Comprehensive genotyping in 155 unrelated, well defined patients from southern Germany. 1072 40

More than 90% of cases of congenital adrenal hyperplasia (CAH, the inherited inability to synthesize cortisol) are caused by 21-hydroxylase deficiency. Females with severe, classic 21-hydroxylase deficiency are exposed to excess androgens prenatally and are born with virilized external genitalia. Most patients cannot synthesize sufficient aldosterone to maintain sodium balance and may develop potentially fatal "salt wasting" crises if not treated. The disease is caused by mutations in the CYP21 gene encoding the steroid 21-hydroxylase enzyme. More than 90% of these mutations result from intergenic recombinations between CYP21 and the closely linked CYP21P pseudogene. Approximately 20% are gene deletions due to unequal crossing over during meiosis, whereas the remainder are gene conversions--transfers to CYP21 of deleterious mutations normally present in CYP21P. The degree to which each mutation compromises enzymatic activity is strongly correlated with the clinical severity of the disease in patients carrying it. Prenatal diagnosis by direct mutation detection permits prenatal treatment of affected females to minimize genital virilization. Neonatal screening by hormonal methods identifies affected children before salt wasting crises develop, reducing mortality from this condition. Glucocorticoid and mineralocorticoid replacement are the mainstays of treatment, but more rational dosing and additional therapies are being developed.
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PMID:Congenital adrenal hyperplasia due to 21-hydroxylase deficiency. 1085 54

A female newborn (46, XX) with ambiguous genitalia was initially diagnosed by biochemical criteria as having classical congenital adrenal hyperplasia caused by 11beta-hydroxylase deficiency. Shortly after effective treatment was administered, she developed a salt-wasting crisis with severe electrolyte imbalance. DNA analysis revealed a homozygous splice mutation in the second intron of the CYP21 gene, for which both parents were heterozygous. No mutations were found in the entire CYP11B1 gene, thus proving that the 11beta-hydroxylase deficiency was not caused by a gene mutation but rather was a secondary event, possibly due to androgen suppression of 11beta-hydroxylase activity.
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PMID:Combined 21-hydroxylase and 11beta-hydroxylase deficiency: patient report and molecular basis. 1096 84

To facilitate a rapid and practical molecular diagnosis of 21-hydroxylase deficiency (21-OHD), we developed a polymerase chain reaction (PCR) test in which only the 21-OH gene (CYP21) is amplified. We applied the test to diagnose 23 patients with salt-wasting type of 21-OHD. The upstream and downstream sequences of CYP21 have been specifically amplified by using a primer set containing the 8-bp deletion sequence of exon 3, which is distinct from its pseudogene CYP21P. The amplified PCR products were further subjected to mutation detection by restriction analysis: E1PL by AciI, I2g by PstI, E63a by DraIII, E7VL by ApaLI, E8non by PstI, and E8RW by AciI. To detect delections and/or gene conversions occurring on exon 3, we used the method described by Rumsby and Honour [1990: J Med Genet 27:676-678]. Our method is able to elucidate 8 common CYP21 mutations by using only 3 primer pairs and 4 restriction enzymes. The overall detection ratio of abnormal haplotypes by this method was over 95%, indicating that our method is practical and useful, particularly for carrier detection.
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PMID:Rapid screening method to detect mutations in CYP21, the gene for 21-hydroxylase. 1098 78

We determined the frequency of large rearrangements and point mutations in 130 Brazilian patients with 21-hydroxylase deficiency and correlated genotype with phenotype. The frequency of CYP21 deletions was lower (4.4%) than in most of the previous series described, whereas the frequency of large gene conversions was similar to the frequency reported in the literature (6.6%). The most frequent point mutations were I2 splice (41.8% in salt wasting - SW), I172N (32.6% in simple virilizing - SV) and V281L (40.2% in the late onset form - LO). The frequency of the nine most common point mutations was similar to that reported for other countries. The 93 fully genotyped patients were classified into 3 mutation groups based on the degree of enzymatic activity (A<2%, B approximately 2%, C>20%). In group A, 62% of cases presented the SW form; in group B, 96% the SV form, and in group C, 88% the LO form. We diagnosed 80% of the affected alleles after screening for large rearrangements and 15 point mutations. To diagnose these remaining alleles we sequenced the CYP21 gene of one patient with the SV form and identified a heterozygous G-->A transition in codon 424. This mutation leads to a substitution of glycine by serine in a conserved region and was also found in a compound heterozygous state in 4 other patients. The mutation G424S presented a linkage disequilibrium with CYP21P and C4A gene deletions and HLA DR17, suggesting a probable founder effect. Search for the G424S mutation in other populations will reveal if it is restricted to the Brazilian patients or if it has a wider ethnic distribution.
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PMID:21-Hydroxylase deficiency in Brazil. 1100 22

Studies which evaluate the psychosocial development and integration of adult female congenital adrenal hyperplasia (CAH) patients are rare but show that patients with the salt wasting form are significantly more virilized and more frequently single and childless. Major complaints are irregular menstruation, hirsutism, acne, obesity, deep voice, and cushingoid features. Surprisingly, a higher prevalence of psychosomatic disorders has not yet been described. Since anorexia nervosa (AN) has not yet been described in patients with CAH, we here report 4 cases of female CAH patients who developed AN during adolescence. Diagnosis of CAH was made between the age of 10 days and 3 years. Three patients suffer from the simple-virilizing form of CAH, one patient has a mild salt wasting CAH. Genital malformation varied from Prader stage II to IV. All 4 patients were compound heterozygotes for mutations/deletions of the CYP21B gene. Control of substitution therapy consisting of hydrocortisone and fluorocortisone was good. AN developed at ages 12, 13, 17, and 21 years (ICD 10 criteria for AN are BMI below 17.5 kg/m2, deliberate weight loss, body image disturbance, and primary or secondary amenorrhoea). Diagnosis of AN was established by psychiatrists and/or psychologists. All four patients showed an impressive and deliberate weight loss between 13 and 20 kg within 6 months, had primary or secondary amenorrhoea, and presented with BMI between 13 and 17.9 kg/m2. All patients received psychological treatment and recovered. However, one patient had a severe relapse of AN. Two patients are now married and one has a healthy son. These cases demonstrate that the diagnosis of CAH is compatible with the development of AN and illustrate the importance of providing treatment for CAH patients that encompasses not only medical but also psychological and social care.
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PMID:Anorexia nervosa in congenital adrenal hyperplasia: long-term follow-up of 4 cases. 1102 57

A case of nonclassic (NC) 21-hydroxylase deficiency, with a moderately elevated 17-hydroxyprogesterone level (145 nmol/L in filter paper blood spot), was detected in newborn screening. The newborn's phenotype was female, with no sign of virilization. Confirmatory diagnosis revealed elevated serum levels of 17-hydroxyprogesterone and of 21-desoxycortisol, whereas cortisol, PRA, and electrolytes were normal. Hydrocortisone substitution was considered at the age of 6 months, when virilization became obvious. For clinical reasons, this case had to be classified as late-onset congenital adrenal hyperplasia (CAH) with unusually early manifestation. However, the diagnosis of classic 21-hydroxylase deficiency was obtained by Southern blotting studies, showing that she was homozygous for the 30-kb deletion, including the 3' end of CYP21P pseudogene, the C4B gene, and the 5' end of the functional CYP21 gene. Further studies, using PCR and sequencing, were conducted to explain the discrepancy between this genotype, usually associated with a classic salt-wasting form, and the girl's phenotype. Typically, patients homozygous for the 30-kb deletion encoding classic CAH possess a unique CYP21P/21 hybrid gene with the junction site located after the third exon, yielding a nonfunctional pseudogene. The girl in question, however, was heterozygous for the 8-bp deletion, suggesting that the chimeric pseudogene on one allele had a junction site before the third exon. She was compound heterozygous for a 30-kb deletion encoding classic CAH on the paternal allele, and a 30-kb deletion encoding NC CAH on the maternal allele. This novel maternal CYP21P/21 hybrid gene is characterized by a junction site before intron 2 and differs from the normal CYP21 gene only by the P30L mutation in exon 1 and the promoter region of the CYP21P pseudogene. Because the P30L mutation has been described to result in an enzyme with 30-60% activity of the normal P450c21 enzyme, and the CYP21P promoter reduced the transcription to 20% of normal, this puzzling phenotype of a NC CAH with early onset may be fully explained by the genotype of the patient and considered as an intermediate form between the simple virilizing and NC form.
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PMID:How a patient homozygous for a 30-kb deletion of the C4-CYP 21 genomic region can have a nonclassic form of 21-hydroxylase deficiency. 1113 9

Congenital adrenal hyperplasia (CAH) is the commonest cause of female pseudohermaphroditism. It is most often due to steroid 21-hydroxylase deficiency resulting from mutations in the CYP21 gene. This study was conducted to characterize mutations in the CYP21 gene, determine their frequency and correlate genotype with phenotype in Indian children with CAH. Twenty-eight patients with salt-wasting (SW) or simple-virilizing (SV) forms of the disease as well as parents and siblings were studied. Allele specific PCR was carried out and rapid characterization of six mutations was achieved in 23 patients. Twelve patients were homozygous for the mutations and 11 were heterozygous, of whom eight were compound heterozygotes and three were hemizygotes; no mutation was found in five patients. The homozygosity of the mutations was found to be high in our population. The most common mutation was Ile173Asn (31.8%), followed by intron2 splice (27.2%), Gln319stop (22.7%), gene deletion (15.9%) and Pro31Leu (2.2%). Genotype-phenotype correlations showed that the most frequent mutations in the SW group were intron2 splice and Gln319stop mutations (33.3% each) and Ile173Asn (71.4%) in the SV group.
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PMID:Molecular characterization of mutations in Indian children with congenital adrenal hyperplasia due to steroid 21-hydroxylase deficiency. 1122 Jul 1

Defective steroid synthesis due to 21-hydroxylase deficiency is the most common form of congenital adrenal hyperplasia. Knowledge of the molecular defects causing 21-hydroxylase deficiency in different populations is of both theoretical and practical interest. The types and the relative frequencies of molecular defects and the correlation between the genotype and the phenotype were examined in the Hellenic population. We searched for deletions, conversions, and 11 of the most frequent mutations of the CYP21 gene by Southern blot and allele-specific PCR in 222 chromosomes from 111 unrelated subjects and their parents. The most frequent molecular defects were 1) in the salt wasting form, I(2) splice (42.9%), deletions and conversions (24.5%), and Q318stop (14.3%); 2) in the simple virilizing form, I172N (35.3%), I(2) splice (29.4%), and P30L (19.1%); and 3) in the nonclassical form, V281L (41.1%), P30L (21.4%), and P453S (14.3%). Compared with other populations, Greek patients had a higher frequency of Q318stop in the salt-wasting form, of P30L in both simple virilizing and nonclassical forms and of P453S in the nonclassical form. The concordance of genotype to phenotype in the total sample was 87%. However, the concordance rate was different in the three forms of the disease. Thus, complete concordance was detected in the genotypes predicting the salt-wasting phenotype, a slightly lower concordance (95.2%) was detected in the genotypes predicting the simple virilizing phenotype, and the lowest concordance (67.6%) was observed in genotypes predicting the nonclassical phenotype. In conclusion, the concordance between genotype and phenotype decreases as the severity of the disease diminishes. This should be taken into consideration in genetic counseling and antenatal intervention.
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PMID:The spectrum of molecular defects of the CYP21 gene in the Hellenic population: variable concordance between genotype and phenotype in the different forms of congenital adrenal hyperplasia. 1139 97


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