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Mutations in the type II 3β‐hydroxysteroid dehydrogenase (HSD3B2) gene can cause premature pubarche in girls
Author(s) -
Suemi Marui,
Margaret de Castro,
Ana Cláudia Latronico,
Lucila Leico Kagohara Elias,
Ivo Jorge Prado Arnhold,
Ayrton Custódio Moreira,
B. B. Mendonça
Publication year - 2000
Publication title -
clinical endocrinology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.055
H-Index - 147
eISSN - 1365-2265
pISSN - 0300-0664
DOI - 10.1046/j.1365-2265.2000.00873.x
Subject(s) - endocrinology , medicine , exon , biology , mutation , dehydrogenase , gene , gene mutation , precocious puberty , hormone , genetics , enzyme , biochemistry
OBJECTIVE Most previous studies have failed to demonstrate any mutations in the type II 3β hydroxysteroid dehydrogenase (HSD3B2) gene in patients satisfying the hormonal criteria of nonclassic 3β‐hydroxysteroid dehydrogenase deficiency, suggesting that a mutant 3β‐hydroxysteroid dehydrogenase protein is not the cause of this disorder. We screened the HSD3B2 gene for mutations in girls with premature pubarche and a hormonal diagnosis of 3β‐hydroxysteroid dehydrogenase deficiency. DESIGN From 30 girls with premature pubarche, we selected 9 whose ACTH‐stimulated 17‐hydroxypregnenolone levels were elevated (≥6 SD) and screened the HSD3B2 gene for mutations. MEASUREMENTS All patients were submitted to a standard ACTH stimulation test. Serum steroids were measured and compared to the mean level of pubertal stage matched control subjects. The four exons and exon‐intron boundaries of the HSD3B2 gene were amplified by polymerase chain reaction and screened for mutations by denaturing gradient gel electrophoresis. The fragments with abnormal migration on denaturing gradient gel electrophoresis were directly sequenced. RESULTS A homozygous T259M mutation was identified in one girl and a new compound heterozygous G129R/P222H mutation was identified in two sisters. The highest ACTH‐stimulated 17‐hydroxypregnenolone levels, 147, 339 and 351 nmol/l, were found in those patients with mutations in the HSD3B2 gene. In the patients without mutations, ACTH‐stimulated 17‐hydroxypregnenolone ranged from 48 to 111 nmol/l. ACTH‐stimulated dehydroepiandrosterone levels had an overlap among the girls with and without mutations and the normal controls. CONCLUSIONS Premature pubarche can be caused by mutations in the type II 3β hydroxysteroid dehydrogenase gene.