ABSTRACT
OBJECTIVES: (1) Characterize serum (S) and urinary (U) steroid metabolites in complete CYP17 deficiency (cCYP17D); (2) analyze the relative 17α-hydroxylase (17OH) and 17,20-lyase (17,20L) activities in vivo; and (3) comparedata from the two most prevalent mutations in Brazil. SUBJECTS AND METHODS: 20 genotyped cCYP17D patients from a previously reported cohort were homozygous for W406R or R362C; 11 controls were CYP17 wild types (WT). WT and cCYP17D patients had S and U samples drawn to measure: cortisol (F), corticosterone (B), deoxycorticosterone (DOC), 18OH-B, 18OH-DOC, and 17OHP; and tetrahydro (TH)-B, THA, THDOC, THF+5α-THF, TH-cortisone, androsterone, etiocholanolone, 5-pregnenediol, 17OH-pregnenolone and pregnanetriol. RESULTS: Compared to WT, cCYP17D patients had marked elevations of B, DOC, 18OH-B and 18OH-DOC, whereas 17OHP, F and adrenal androgens (AA) were reduced; U steroids parallel S findings. Metabolite ratios revealed that both 17OH and 17,20L activities were impaired in cCYP17D. There were nodifferences between W406R andR362C mutations. CONCLUSIONS: cCYP17D patients show parallel overproduction/overexcretion of 17-deoxysteroids, and marked reduction of F and AA. In addition to 17OH, 17,20-L activity was also impaired in cCYP17D. W406 and R362C mutations disclose similar Sand U patterns.
OBJETIVOS: (1) Caracterizar os esteroides séricos (S) e urinários (U) na deficiência completa da CYP17 (DcCYP17); (2) analisar as atividades da 17α-hidroxilase (17OH) e 17,20-liase (17, 20 L) in vivo; e (3) comparar as duas mutações mais prevalentes no Brasil. SUJEITOS E MÉTODOS: 20 pacientes genotipados para a DcCYP17, de uma coorte anterior, eram homozigotos para W406R ou R362C (8 cada); 11 controles eram CYP17 wild types (WT). Amostras de S e U foram colhidas dos WT e pacientes para dosagem de: cortisol (F), corticosterona (B), deoxicorticosterona (DOC), 18-OH-B, 18OH-DOC e 17OHP; e tetraidro(TH)-B, THA, TH-DOC, THF+5α-THF, THE, androsterona, etiocolanolona, 5-pregnenediol, 17OH-pregnenolona e pregnanetriol. RESULTADOS: Comparados aos WT, os pacientes com DcCYP17 revelaram elevações acentuadas de B, DOC, 18OHB e 18OHDOC, enquanto 17OHP, F e andrógenos adrenais (AA) estavam reduzidos. Os esteroides na U acompanham os achados no S. As relações de metabólitos mostraram que as atividades de 17OH e 17,20L estavam reduzidas em pacientes com DcCYP17. Não houve diferenças entre pacientes com as mutações W406R e R362C. CONCLUSÕES: Na DcCYP17, a produção e a excreção dos 17-deoxiesteroides estão aumentadas em paralelo, em contraste com a reduzida produção/excreção de F e AA. As atividades da 17OH e 17,20-L estão diminuídas na DcCYP17. As mutações W406 e R362C apresentam achados semelhantes em S e U.
Subject(s)
Adolescent , Adult , Female , Humans , Male , Middle Aged , Young Adult , Adrenal Hyperplasia, Congenital/urine , /urine , Adrenal Hyperplasia, Congenital/genetics , Androgens/urine , Case-Control Studies , Hydrocortisone/urine , Mutation/genetics , /geneticsABSTRACT
Objective To study the molecular genetic mechanism of a patient with 17? hydroxylase (CYP17) deficiency. Methods Genomic DNA were abstracted from the blood of the patient, her parents and healthy control. The 8 exons of CYP17 gene were amplified, using 5 pairs of designed primers, with polymerase chain reaction (PCR), and the 8 exons were sequenced by the dideoxy terminator method to determined the mutation sites. The corresponding exons of the parents of the patients were also amplified and sequenced to determine the zygosity of the patient and the source of the gene variances. Results The analysis revealed that the patient (46, XY) was a compound heterozygote carrying two different inherited mutations on CYP17 gene, one from mother containing a point mutation Arg 96 (C G G)→ Gln(C A G) and the other from father containing a nine base deletion (CACTCTTTC) at amino acid position 487～489 (Asp Ser Phe) near the carboxyl terminus of P450c17. Conclusion The CYP17 gene of the patient with 17? hydroxylase deficiency is a compound heterozygous mutation. The mutation changes the amino acid sequence of P450c17 enzyme, which in turn affected the enzymatic activity. Arg 96 is essential in P450c17 enzyme activity. Deletion of Asp 487 Ser 488 Phe 489 in exon 8 may be a prevalent mutation causing P450c17 deficiency in Southeast Asia.