The mild nonclassic form of steroid 21-hydroxylase deficiency is one of the most common autosomal recessive disorders in humans, occurring in almost 1% of caucasians and about 3% of Ashkenazi Jews. Many patients with this disorder carry a Val-281----Leu missense mutation in the CYP21 gene. This and most other mutations causing 21-hydroxylase deficiency are normally present in the CYP21P pseudogene and have presumably been transferred to CYP21 by gene conversion. To identify other potential nonclassic alleles, we used recombinant vaccinia virus to express two mutant enzymes carrying the mutations Pro-30----Leu (normally present in CYP21P) and Ser-268----Thr (considered a normal polymorphism of CYP21). Whereas the activity of the protein carrying the Ser----Thr mutation was indeed indistinguishable from the wild type, the enzyme with the Pro----Leu substitution had 60% of wild-type activity for 17-hydroxyprogesterone and about 30% of normal activity for progesterone when assayed in intact cells. When kinetic analysis of the latter mutant enzyme was performed in cellular lysates, the first order rate constants (maximum velocity/dissociation constant) for both substrates were reduced 10- to 20-fold compared with those for the wild-type enzyme. Pro-30 is conserved in many microsomal P450 enzymes and may be important for proper orientation of the enzyme with respect to the aminoterminal transmembrane segment. The Pro----Leu mutation was present in 5 of 18 patients with nonclassic 21-hydroxylase deficiency, suggesting that this mutation indeed acts as a nonclassic deficiency allele.
Nonclassic steroid 21-hydroxylase deficiency is an attenuated adrenal enzyme defect that is commonly the basis of hyperandrogenic syndromes. Inherited as an autosomal recessive trait, it is known to occur with high frequency in the general population and with increased frequency in a number of ethnic groups, including the Yugoslav population. Following expansion of the original data on 21 families in Croatia to a total of 49 Croatian and Serbian families, we establish that this enzymatic disorder is increased in this Slavic population and provide an updated estimate for the gene frequency of 0.092 (0.035\x=req-\ 0.149). Also in keeping with earlier reports, we continue to note the absence of association between nonclassic 21\ x=r eq-\ hydroxylase deficiency occurring among Yugoslavs and HLA-B14;DR1.Nonclassic steroid 21-hydroxylase deficiency is an autosomal recessive disorder that is known to occur with very high frequency generally, and which in addition shows increased prevalence in certain ethnic populations (1). This partial adrenal enzyme defect may or may not be clinically manifest in af¬ fected individuals, but can be identified by hor¬ mone criteria. Mild to moderate elevations of serum androgens result from increased secretion by the adrenal of androgens and of androgenic precursors which undergo peripheral conversion to active hormones. Biochemical indices of reduced adrenal 21-hydroxylation are serum elevations of the steroid intermediates 17a-hydroxyprogesterone (17-OHP), the principal substrate of 21-hy-droxylase, which fails to be converted to 11-deoxycortisol (compound S), the direct precursor of Cor¬ tisol, and also of A4-androstenedione (A4-A), im¬ mediately distal to 17-OHP in the androgenic pathway. Clinical effects arising from 21-hydroxy¬ lase deficiency vary between individuals and the different ages within the same individual.The first population genetic study on nonclassic 21-hydroxylase deficiency (1) identified an in¬ creased incidence among Yugoslavs, estimating the gene frequency among this population to be 0.125 (0.042-0.268 (95% confidence limits)) based on data from 21 families in Zagreb, SR Croatia, Yu¬ goslavia (1). This study observed that positive link¬ age disequilibrium between nonclassic 21-hydroxy¬ lase deficiency and HLA-B14;DR1 existing in other ethnic groups at increased risk, Ashkenazic Jews, Hispanics, and Italians, was absent in the Yu¬ goslav patient group.The population genetic analysis of the original study in 167 families was based on inference of genotype and gene counting as follows: Obligate hétérozygotes (the parents of affected offspring) in each pedigree were genotyped by HLA association and ACTH stimulation hormone testing. Occur¬ rence of the nonclassic deficiency trait in a tested parent identified the presence of a nonclassic de¬ ficiency alíele also on the second haplotype. Con¬ sidering that the second (nontransmitted) haplotypes of known hétérozygotes still represent a Klinika za djecje bolesti REBRO1 and Centar za tipizaciju tkiva REBRO2,
We describe two sisters (40 and 42 years old) heterozygous for adrenoleukodystrophy who have multiple endocrine disorders. In addition to the characteristic neurological symptoms, the younger patient has Addison disease and primary hypothyroidism attributable to autoimmune thyroiditis, and the older one has Graves disease. Both patients have loss of body hair and sparse scalp hair, which have not been reported previously in women heterozygous for adrenoleukodystrophy. After the institution of glucocorticoid replacement therapy, the younger sister, who has adrenal insufficiency, has shown unexpected neurological improvement.
No abstract
The CYP21A2 mutations that are in linkage disequilibrium with particular HLA-A, -B, -DRB1 alleles/haplotypes, cause deficiency of the 21-hydroxylase enzyme (21-OHD) and account for the majority of congenital adrenal hyperplasia (CAH) cases. The aim of this study was to investigate those associations with the p.V282L mutation linked to the non-classical (NC) form of CAH among Croatians. The study included parents of patients with the NC form of CAH, positive for the p.V282L mutation (N = 55) and cadaveric donor samples (N = 231). All subjects were HLA-A, -B, and -DRB1 typed and tested for the presence of the p.V282L mutation. Among parents of patients, 92.73% of subjects were positive for the B*14:02 allele and almost half of them carried the HLA-A*33:01-B*14:02-DRB1*01:02 haplotype. Among cadaveric samples 77 out of 96 subjects positive for the B*14:02 allele had the p.V282L mutation. Among them, 37 were positive for the HLA-A*33:01-B*14:02-DRB1*01:02 haplotype, 23 had the HLA-A*33:01-B*14:02-DRB1*03:01 haplotype, 8 had the B*14:02-DRB1*01:02 combination and 5 were carrying the HLA-A*68:02-B*14:02-DRB1*13:03 haplotype. Only 4 of these subjects were positive for the B*14:02 allele. HLA-B*14:02 was the only single allele with association that reached statistically significant P value (RR = 12.00; P = 0.0024). Haplotypes B*14:02-DRB1*01:02 (P < 0.001) and HLA-A*68:02-B*14:02-DRB1*13:03 (P < 0.001) as well as HLA-A*33:01-B*14:02-DRB1*01:02 and HLA-A*33:01-B*14:02-DRB1*03:01 showed high relative risks (RR = 45.00, RR = 41.63 and RR = 36.96, respectively). Our data support the previously documented association of the HLA-A*33:01-B*14:02-DRB1*01:02 haplotype with the p.V282L mutation, but also point out a high frequency of the p.V282L mutation among Croatians with HLA-A*33:01-B*14:02-DRB1*03:01 and HLA-A*68:02-B*14:02-DRB1*13:03 haplotypes.
Five individuals with the asymptomatic, 'nonclassical', 'cryptic' form of congenital adrenal hyperplasia (CAH) due to 21-hydroxylase (21-OH) deficiency from 5 unrelated families were discovered during hormonal studies and HLA-typing performed in a series of 24 families with CAH due to 21-OH deficiency. Four of the 5 individuals with the 'cryptic' form of CAH belong to families where the index case was a patient with the classical form of CAH due to 21-OH deficiency. The fifth one originated from a family where the index case was a girl with the 'non-classical', 'late-onset' form of the disease. All the 5 individuals had no clinical symptoms in spite of clearcut biochemical signs of 21-OH deficiency: increased 17-OH-progesterone (17-OHP), dehydroepiandrosterone and androstenedione levels, particularly after ACTH-stimulation. The 17-OHP response upon ACTH stimulation of heterozygotes for this 'non-classical' form of 21-OH deficiency did not differ from the response of heterozygous individuals for the classical form of the disease. The results of this study confirm the hypothesis that individuals with the 'cryptic' form of CAH due to 21-OH deficiency are genetic compounds bearing one allele for the severe, classical form, and on the homologous locus, another one for the mild 'nonclassical' form of CAH due to 21-OH deficiency. Their genotype was 21-OHsevere/21-OHmild, The gene for 'cryptic' 21-OH deficiency, as well as the gene for the classical form of the disease is linked to the HLA system, but in our population apparently it is not in genetic disequilibrium with the antigens B 14 DR 1, as it was shown for other populations studied up to now.
We report on a patient with Nevo syndrome manifesting intrauterine and postpartum overgrowth, accelerated osseous maturation, dolichocephaly, highly arched palate, large, low-set ears, cryptorchidism, delayed neuropsychological development, hypotonia, adema, contractures of the hands and feet, a single a transverse palmar crease, and tapering digits. After meningococcal sepsis at age 6 months, he remained decerebrate. Thereafter, overgrowth and especially weight gain were extremely accelerated until his death at age 18 months, at which time his height was 103 cm and his weight was 23 kg. In addition to low plasma concentrations of growth hormone and insulin-like growth factor, severe insulin resistance was observed. It is presumed that a selective defect in insulin-stimulated glucose uptake, with preservation of anabolic effect, was one of the causes of his "overgrowth without growth hormone," at least in the last 12 months of life after severe brain damage. Am.
We describe a 26-year-old patient with 17-ketoreductase deficiency who was raised as a male from 8 months and whose left testis was brought down at the age of 2.5 years and the right testis at the age of 4. Despite the early orchidopexy and not significantly decreased serum testosterone, he was sterile, and biopsy of the testes at the age of 26 revealed absence of spermatogenesis. This case indicates that the absence of spermatogonia in previously reported patients whose testes remained undescended until a later age could not be attributed solely to cryptorchidism. We suggest that decreased intratesticular testosterone due to steroidogenic defect in the developing testis mainly contributes to the arrest of spermatogenesis.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.