title: P450c17 deficiency in Brazilian patients: biochemical diagnosis through progesterone levels confirmed by CYP17 genotyping.
abstract: P450c17 deficiency is an autosomal recessive disorder and a rare cause of congenital adrenal hyperplasia characterized by hypertension, hypokalemia, and impaired production of sex hormones. We performed a clinical, hormonal, and molecular study of 11 patients from 6 Brazilian families with the combined 17alpha-hydroxylase/17,20-lyase deficiency phenotype. All patients had elevated basal serum levels of progesterone (1.8-38 ng/ml; 0.57-12 pmol/liter) and suppressed plasma renin activity. CYP17 genotyping identified 5 missense mutations. The compound heterozygous mutation R362C/W406R was found in 1 family, whereas the homozygous mutations R96W, Y329D, and P428L were seen in the other 5 families. The R96W mutation has been described as the cause of p450c17 deficiency in Caucasian patients. The other mutations were not found in 50 normal subjects screened by allele-specific oligonucleotide hybridization (Y329D, R362C, and W406R) or digestion with HphI (P428L) and were recently found in other Brazilian patients. Therefore, we elucidated the genotype of 11 individuals with p450c17 deficiency and concluded that basal progesterone measurement is a useful marker of p450c17 deficiency and that its use should reduce the misdiagnosis of this deficiency in patients presenting with male pseudohermaphroditism, primary or secondary amenorrhea, and mineralocorticoid excess syndrome.
authors.affiliation: Unidade de Endocrinologia do Desenvolvimento, Divisão de Endocrinologia, Hospital das Clínicas da Faculdade de Medicina da Universidade de Sao Paulo, Sao Paulo, SP, Brazil. reginamm@usp.br
authors.forename: Regina M
authors.initials: RM
authors.lastname: Martin
authors.forename: Chin J
authors.initials: CJ
authors.lastname: Lin
authors.forename: Elaine M F
authors.initials: EM
authors.lastname: Costa
authors.forename: Maria Leocadia
authors.initials: ML
authors.lastname: de Oliveira
authors.forename: Alexandre
authors.initials: A
authors.lastname: Carrilho
authors.forename: Heloisa
authors.initials: H
authors.lastname: Villar
authors.forename: Carlos A
authors.initials: CA
authors.lastname: Longui
authors.forename: Berenice B
authors.initials: BB
authors.lastname: Mendonca
mesh_terms: D000293:Adolescent; D000312:Adrenal Hyperplasia, Congenital / Q000097:blood / Q000150:complications / Q000175:diagnosis* / Q000235:genetics*; D000328:Adult; D001483:Base Sequence / Q000235:genetics; D001938:Brazil; D016022:Case-Control Studies; D002648:Child; D002675:Child, Preschool; D003937:Diagnosis, Differential; D012734:Disorders of Sex Development / Q000209:etiology; D005260:Female; D005838:Genotype; D006579:Heterozygote; D006720:Homozygote; D006728:Hormones / Q000097:blood; D006801:Humans; D008297:Male; D020125:Mutation, Missense; D011374:Progesterone / Q000097:blood*; D013254:Steroid 17-alpha-Hydroxylase / Q000235:genetics*
chemical_list: D006728:Hormones; D011374:Progesterone; D013254:Steroid 17-alpha-Hydroxylase