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Query: UMLS:C0042755 (
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2,562
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The possibility of using TaqI restriction fragment length polymorphism (RFLP) analysis of the HLA-B locus and the HLA-DR-DQ subregions, flanking the 21-hydroxylase genes, for predicting disease in siblings of children with 21-hydroxylase deficiency was analyzed in 12 nuclear families with at least one affected child and a total of 18 at-risk off-spring. As part of the study allelic TaqI HLA-B RFLP patterns were determined in homozygous cell lines and families. The frequencies of individuals homozygous for TaqI allelic patterns of the different investigated
HLA
loci, each locus alone and in various combinations, were determined in 100 random controls. In all 12 families it was possible to make correct genetic diagnosis by the use of only one restriction enzyme, TaqI, and two locus-specific
HLA
cDNA probes, HLA-B and -DRB. In all families four haplotypes were obtained. Thus, affected siblings as well as carriers could be identified. Seven of the eight sibling pairs concordant for 21-hydroxylase deficiency had pairwise identical TaqI HLA-B-DRB-DQA-DQB haplotypes. The last disease-concordant sibling pair had inherited different haplotypes from their mother, who had nonclassical 21-hydroxylase deficiency. None of the ten healthy children shared both haplotypes with their affected sibling(s). Early prenatal suppression of the fetal adrenal cortex with fluorinated corticosteroids can prevent
virilization
of female fetuses with 21-hydroxylase deficiency. In most cases RFLP analysis of the 21-hydroxylase genes is not informative enough for prenatal diagnosis. Our results from the present retrospective family study indicate that TaqI HLA-B and -DRB RFP analysis will be a valuable tool for first trimester assessment of 21-hydroxylase deficiency. TagI HLA-B and -DRB RFLP analysis can be performed on DNA from chorionic villi biopsies obtained in the 8th week of pregnancy. Supplemented with sex determination, early withdrawal of prophylactic steroid therapy will thus be feasible when the mother carries a male or an unaffected female fetus.
...
PMID:TaqI HLA-B and -DRB RFLP analysis can predict disease in siblings of affected children with 21-hydroxylase deficiency. 197 80
A mother at risk for 21-hydroxylase deficiency was treated with oral dexamethasone (0.5 mg 12 hourly) from early pregnancy, in an attempt to prevent in utero
virilization
in case of a female fetus. Fetal karyotype was 46,XX, and because of a possible intra
HLA
recombination, treatment was continued to term. The newborn had a modest
virilization
and hormonal studies confirmed the diagnosis of congenital adrenal hyperplasia (CAH). This observation and review of the literature suggest that efficient prenatal treatment of CAH requires a higher and more frequent dosage of dexamethasone.
...
PMID:Prenatal treatment of congenital adrenal hyperplasia: report of a new case. 240 46
The adrenogenital syndrome (AGS) is a relatively common inherited metabolic disease, generally caused by a deficiency of the adrenocortical enzyme steroid 21-hydroxylase. This results in an insufficient biosynthesis of several important steroid hormones such as cortisol and aldosterone, and, on the other hand, in a strongly increased production of androgens (testosterone). In girls,
virilization
of the external genitals is usually seen. In some patients, severe salt loss occurs shortly after birth, and a life-threatening crisis may develop. Mild variants of the disease have also been described. Steroid 21-hydroxylase is encoded by a gene within the
HLA
complex on the short arm of chromosome 6.
HLA
typing thus allows the study of the hereditary transmission of several forms of the AGS. In addition, molecular biology at present opens new perspectives to fundamental and clinical genetic research.
...
PMID:[Adrenogenital syndrome. I. Introduction, enzymology and heredity]. 267 99
Congenital adrenal hyperplasia due to 21-hydroxylase deficiency can result in marked
virilization
of the external genitalia of affected female subjects. Theoretically, suppression of the fetal pituitary-adrenal axis with glucocorticoid during gestational weeks 9 to 17 should prevent the development of ambiguous genitalia in the female fetus. Prenatal diagnosis of congenital adrenal hyperplasia can be made on elevated amniotic fluid 17-hydroxyprogesterone and adrenal androgen concentrations, and
HLA
typing of cultured amniotic fluid cells. However, these tests cannot be completed before 16 to 17 weeks of gestation, and maternal therapy would have to be instituted before the exact genetic status of the fetus is known. Chorionic villus sampling during the first trimester provides an alternative to second trimester diagnosis in patients who are at risk for bearing offspring with congenital adrenal hyperplasia. We report the use of dexamethasone suppression at 8 weeks of gestation in a 34-year-old woman whose son had congenital adrenal hyperplasia due to severe salt-losing 21-hydroxylase deficiency and whose biopsy revealed a 46XX chromosomal pattern. Cultured cells from the biopsy confirmed the fetus to be of identical
HLA
haplotype to the previous affected sibling. At 41 weeks the patient delivered a female neonate with minimal prominence of the clitoris, mildly rugated labia, a single perineal opening and minimal posterior labial fusion. Postnatal tapering of maternal steroids was performed with no long-term sequelae.
...
PMID:Prenatal fetal adrenal suppression following in utero diagnosis of congenital adrenal hyperplasia. 274 96
Prenatal treatment with dexamethasone starting with gestation week 5 has been proposed to prevent
virilization
of female fetuses with congenital adrenal hyperplasia (CAH) due to 21-hydroxylase deficiency. We report dexamethasone treatment in a mother during her third pregnancy; this treatment could not be started before the 12th week of gestation. The second child (index case) had a simple virilizing 21-hydroxylase deficiency CAH and Prader IV genitalia. Because after amniocentesis a normal female karyotype and
HLA
identity with the index case were found, the dexamethasone treatment (3 x 0.5 mg/die) was continued until delivery.-In contrast to patients with salt-wasting CAH, the 17-alpha-hydroxyprogesterone level in the amniotic fluid was within the normal range. Decreased maternal plasma and urine estriol concentrations, as well as the plasma cortisol values, demonstrated adequate suppression of the fetal and maternal adrenal gland. No side effects were found in the mother as a result of the dexamethasone treatment. The newborn had
virilization
of the external genitalia according to Prader III but without hypertrophy of the clitoris. The degree of rugated scrotum was less marked in relation to the index case and the sinus urogenitalis was more distally shifted. Thus, surgery on the clitoris could be avoided. The conditions for further surgery (vaginoplasty) could probably be improved. Therefore, dexamethasone treatment of a mother with a female CAH fetus due to 21-hydroxylase deficiency seems to be justified starting at the 12th week of gestation. However, the optimal beginning of therapy is in early pregnancy.
...
PMID:[The effect of maternal dexamethasone treatment after the 12th week of pregnancy on fetal genital development in adrenogenital syndrome with 21-hydroxylase deficiency]. 278 92
Late-onset 21-hydroxylase deficiency (21OHD) presents biochemical evidence of 21OHD and
virilization
in peri-or postpubertal age; it has been demonstrated that late-onset 21OHD is linked to
HLA
system. We present the
HLA
typing, the baseline and the ACTH-stimulated hormonal levels in 5 patients with late-onset 21OHD and in their family members. We identified 3
HLA
identical male sibs within their respective families, 2 sibs sharing one haplotype with the affected member and 2 homozygous normal sibs. We observed elevated baseline (greater than 4 ng/ml) and ACTH-stimulated 17-hydroxyprogesterone levels, increased baseline Androstenedione levels, slightly elevated or normal DHEA-S and Testosterone values and subnormal response of Cortisol levels to ACTH in patients and in the
HLA
-identical sibs, reduced SHBG levels in patients but not in their identical sibs. The heterozygous family members presented hyperresponsiveness of 17-hydroxyprogesterone but not of androgens after ACTH. We confirm that late-onset of 21OHD is an autosomal recessive disease linked to HLA-B; there is in fact biochemical evidence of mild 21OHD in patients and in their
HLA
identical sibs and 17-hydroxyprogesterone levels in the range of heterozygotes for classical 21OHD in parents and sibs predicted by
HLA
to be carriers. Thus
HLA
typing and hormonal data, particularly 17-hydroxyprogesterone, are useful, also in this form of congenital hyperplasia, in detecting heterozygotes.
...
PMID:HLA and hormonal studies in 5 patients with late-onset 21-hydroxylase deficiency syndrome (21OHDS). 300 98
Most patients with male pseudohermaphroditism (MPH) due to 17-ketosteroid reductase (17-KSR) deficiency were diagnosed at or after puberty when significant
virilization
occurred. We report 2 prepubertal sibs (Case 1, 4 yr and Case 2, 10 yr) unambiguously raised as females, with clitoral enlargement, separate urethral and vaginal orifices and gonads palpable at the inguinal canal bilaterally. Basal serum LH, FSH, 17-hydroxyprogesterone, testosterone (T), dihydrotestosterone and dehydroepiandrosterone (DHEA) were normal for age. delta 4-Androstenedione (delta 4-A) was slightly elevated in Case 2 but nondiagnostic. Steroid measurements after human chorionic gonadotropin (hCG) stimulation were compared with those of boys with male external genitalia submitted to the same hCG protocol: peak T was subnormal (Case 1, 80, Case 2, 91, vs normal 329 +/- 129 ng/dl, mean +/- 1SD), peak delta 4-A elevated (Case 1, 477, Case 2, 264, vs normal 44 +/- 26 ng/dl) resulting in an abnormally elevated delta 4-A/T ratio (Case 1, 6.0, Case 2, 2.9, vs normal 0.12 +/- 0.09) and establishing the diagnosis of 17-KSR deficiency. This diagnosis was confirmed in vitro by minimal T production when testicular tissue of both patients was incubated with tritiated delta 4-A. The 2 sibs did not share a single haplotype for the
HLA
complex indicating lack of association between
HLA
and the locus of the gene for 17-KSR. In conclusion, in 2 sibs with MPH the subnormal T and elevated delta 4-A response to the hCG test indicated the diagnosis of 17-KSR deficiency followed by orchiectomy to avoid later
virilization
at puberty.
...
PMID:Prepubertal male pseudohermaphroditism due to 17-ketosteroid reductase deficiency: diagnostic value of a hCG test and lack of HLA association. 316 23
Impairment of 21-hydroxylation is the most common enzymatic deficiency resulting in the syndrome of CAH, which may present either in the classical form in infants or in the nonclassical form in older individuals. Variable signs and symptoms of androgen excess are common to both types of the disorder, which are transmitted as autosomal recessive traits linked to
HLA
.
Virilization
begins in the second month of gestational life in classical 21-OHD, but postnatally in the nonclassical form. Salt wasting is a feature of the disease in a large number of classical patients; in the simple virilizing form aldosterone biosynthesis, a function of the adrenal zona glomerulosa, is intact. Additionally, no patient with nonclassical 21-OHD has been found to have salt wasting. Levels of precursor hormones are less markedly elevated in nonclassical 21-OHD, reflecting a less severe enzyme deficiency; coordinates of basal and stimulated 17-OHP are plotted on a nomogram to ascertain diagnostic category within a family. Confirmatory evidence of heterozygosity within the family of an affected proband is found by performing
HLA
typing. Specific linkage disequilibria exist for the classical and nonclassical forms of 21-OHD. Frequency of the classical disease is 1/5,000-1/15,000 in Caucasians, whereas the nonclassical disease is found in approximately 1/100 individuals in the Caucasian population, placing the latter disorder among the most common autosomal recessive disorders in man. A deletion of the active 21-hydroxylase gene has been detected in some classical patients; further investigations are in progress to elucidate the molecular genetics of this disease.
...
PMID:Genetics of adrenal steroid 21-hydroxylase deficiency. 352 88
We describe three different forms of 21-hydroxylase deficiency-classical congenital adrenal hyperplasia (CAH), late-onset 21-hydroxylase deficiency, and cryptic 21-hydroxylase deficiency-and we present hormonal standards by which to assign the appropriate 21-hydroxylase deficiency genotype for these disorders. The late-onset and cryptic forms of 21-hydroxylase deficiency are biochemically indistinguishable, although patients with the late-onset disorder present with marked clinical symptoms (e.g.
virilization
) whereas patients with cryptic 21-hydroxylase deficiency are clinically asymptomatic. Our latest studies suggest that late-onset 21-hydroxylase deficiency, like the classical and cryptic 21-hydroxylase deficiencies, is also genetically linked to
HLA
, the major histocompatibility complex of man. Our biochemical findings provide evidence that a spectrum of 21-hydroxylase deficiencies exist in the population.
...
PMID:The biochemical basis for genotyping 21-hydroxylase deficiency. 626 88
Serum androgens and 17-hydroxyprogesterone concentrations and
HLA
genotypes were determined in 124 families of patients with congenital adrenal hyperplasia due to 21-hydroxylase deficiency (CAH). In 8 pedigrees, we discovered 16 pubertal or postpubertal family members of either sex who had biochemical evidence of 21-hydroxylase deficiency but were without clinical symptoms of excess
virilism
, amenorrhea, or infertility. We designated these family members as individuals with cryptic 21-hydroxylase deficiency. Within each generation, the family members with cryptic 21-hydroxylase deficiency were
HLA
identical. It is proposed that these family members are genetic compounds, having 21-hydroxylase deficiency as a result of two recessive gene defects: 1) a severe 21-hydroxylase gene defect present in the index case with classical CAH (21-OHCAH) and 2) a mild 21-hydroxylase gene defect (21-OHCRYPTIC). Thus, the CAH genotype in the family members with cryptic 21-hydroxylase deficiency is 21-OHCAH/21-OHCRYPTIC. Lod score analysis for linkage between the cryptogenic 21-OH trait and
HLA
gave a combined Lod score for males and females of theta = 0.00 of 3.409. Close genetic linkage between
HLA
and 21-OHCRYPTIC was thus established. This study provides support for the previously reported heterogeneity of 21-hydroxylase deficiency which may result from allelic variability at the locus for steroid 21-hydroxylase.
...
PMID:Cryptic 21-hydroxylase deficiency in families of patients with classical congenital adrenal hyperplasia. 644 18
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