Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0002453 (amenorrhea)
 6,245 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A new CYP17 gene abnormality was found in three Japanese patients with 17 alpha-hydroxylase deficiency (170HD). These patients were children from consanguineous marriages, but from two apparently unrelated families: one patient with 46, XY karyotype, and two siblings with 46, XX and 46, XY karyotypes. They were all raised as girls and presented with amenorrhea, eunuchoid appearance and hypertension. Gene analysis revealed two base-pair (TG) deletion in exon 5 (codons 300, 301) of the CYP17 gene. This deletion could be expected to alter the reading frame resulting in the lack of a haem-binding region (Cys 442) due to a premature stop codon at position 333. This small mutation may account for the patients' clinical manifestations of 170HD.
 ...
PMID:A new variant of the cytochrome P450c17 (CYP17) gene mutation in three patients with 17 alpha-hydroxylase deficiency. 925 Mar 56

Mutations in the CYP17 gene impair steroid biosynthesis in the adrenals and gonads and often cause 17alpha-hydroxylase/17,20-lyase deficiency, leading to amenorrhea, sexual infantilism, and hypokalemic low aldosterone hypertension. Several CYP17 mutations resulting in 17alpha-hydroxylase/17,20-lyase deficiency have been reported previously. In the present study, we found a novel CYP17 mutation from the molecular analysis of a Korean patient with primary amenorrhea with a 46,XX karyotype, and hypokalemic hypertension. We sequenced all 8 exons of the CYP17 gene that were amplified from patient's genomic DNA using polymerase chain reaction (PCR) and found a compound heterozygous mutation in the CYP17 structural gene; a 1-base deletion and a 1-base transversion (TAC-->AA) at codon 329, leading to the production of a truncated protein (1-417 amino acids), and a 3-base deletion (TCC, either 350-351 or 351-352 codon) in the other allele. Restriction enzyme digestion analysis of patient's and parental DNA showed that the 1-base deletion and the 3-base deletion are inherited from mother and father, respectively. Here we conclude that these novel compound heterozygous mutations might account for the patient's clinical manifestations of 17alpha-hydroxylase/17,20-lyase deficiency.
 ...
PMID:A novel compound heterozygous mutation in the CYP17 (P450 17alpha-hydroxylase) gene leading to 17alpha-hydroxylase/17,20-lyase deficiency. 1270 Oct 64

Polycystic ovary syndrome (PCOS) is a common heterogenous endocrine disorder associated with amenorrhoea (or oligomenorrhoea), hyperandrogenism, hirsutism, obesity, insulin resistance, and an approximately 7-fold increased risk of type 2 diabetes mellitus (NIDDM - non-insulin dependent diabetes mellitus). It is a leading cause of female infertility. The prevalence of PCOS among reproductive-age women has been estimated at 4%-12%. Familial aggregation of this syndrome is well established. There are also ethnic and racial variations in the prevalence of the syndrome and its symptoms. Multiple biochemical pathways have been implicated in the pathogenesis of PCOS. Several genes from these pathways have been tested include genes involved in steroid hormone biosynthesis and metabolism (StAR, CYP11, CYP17, CYP19 HSD17B1-3, HSD3B1-2), gonadotropin and gonadal hormones action (ACTR1, ACTR2A-B, FS, INHA, INHBA-B, INHC, SHBG, LHCGR, FSHR, MADH4, AR), obesity and energy regulation (MC4R, OB, OBR, POMC, UCP2-3), insulin secretion and action (IGF1, IGF1R, IGFBPI1-3, INS VNTR, IR, INSL, IRS1-2, PPARG) and many others. Most women with PCOS, both obese and lean, have a degree of insulin resistance. The minisatellite of insulin gene (INS VNTR), especially class III alleles and III/III genotypes might not only determine the predisposition to anovulatory PCOS but also the concomitant risk for development of type 2 diabetes. The function of the insulin receptor (IR) is probably normal in woman with PCOS. However abnormal serine phosphorylation in the receptor may impair signal transduction accounting for a post-binding defect in insulin action. Serine phosphorylation is also involved in the postranslational regulation of 17,20-lyase activity (CYP17). There may be a common aetiology for both insulin resistance and hyperandrogenism. Polymorphic alleles of both IRS-1 and IRS-2 (insulin receptor substrate 1 - 2), alone or in combination, may have a functional impact on the insulin-resistant component of PCOS. There is no evidence to suggest that follistatin gene polymorphisms play a role in the pathogenesis of insulin resistance in PCOS women. PCOS appears to be associated with the absence of the four-repeat-units allele in a polymorphic region of pentanucleotide (TTTTA)n repeats within CYP11A gene, which encodes cytochrome P450scc. It has been hypothesized that up-regulation of this enzyme could lead to increased androgen production. There is no evidence of any association of alleles of CYP19 gene (encoding cytochrome P450arom) with PCOS. Association exists between androgen receptor gene (AR) polymorphisms an androgens action in PCOS. Increased hirustism and decreased CAG repeat length within AR gene has been also demonstrated in women with normal testosterone levels. Expression of estrogen receptor (ERs) as well as 5-alpha-reeducates (SRD5A1-2 genes) activity was analysed in granulosa (GC) and theca cells (TC). The results of this study demonstrate that there are significant alterations in the expression of ERalpha and ERbeta in PCOS that may be related to abnormal follicular development. On the other hand elevated SRD5A activity in polycystic ovaries supported the hypothesis that 5-alpha-reduced androgens may play a role in the pathogenesis of the syndrome. The genetic aetiology of PCOS remains unknown. There are a number of interlinking factors that affects expression of PCOS. Single cause of PCOS is unlikely. Other possible mechanisms in pathogenesis of PCOS are discussed.
 ...
PMID:[Genetic aspects of polycystic ovary syndrome]. 1635 Jul 21

Mutations in the CYP17 gene impair steroid biosynthesis in the adrenals and gonads, resulting in 17alpha-hydroxylase/17,20-lyase (P450c17) deficiency, leading to amenorrhea, sexual infantilism, hypokalemia, and hypertension. To date, more than 50 mutations in the CYP17 gene associated with congenital adrenal hyperplasia have been described. In this study, we analyzed a 36-year-old phenotypic female, genotypic male, with P450c17 deficiency to compare with an additional group of 50 Chinese subjects without P450c17 deficiency in Taiwan. DNA sequence analysis of the CYP17 gene was performed. The result showed that the proband had a compound heterozygous mutations in exon 6 (CGC-->TGC) that resulted in the substitution of arginine by cysteine at codon 362, and in exon 7 (CCG-->CGG) that resulted in the substitution of proline by arginine at codon 409. In conclusion, we have identified a compound heterozygous mutation in the CYP17 gene in one patient with congenital adrenal hyperplasia in Taiwan.
 ...
PMID:A compound heterozygous mutation in the CYP17 (17alpha-hydroxylase/17,20-lyase) gene in a Chinese subject with congenital adrenal hyperplasia. 1737 8