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5-Alpha Reductase

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David W. Russell – One of the best experts on this subject based on the ideXlab platform.

Dagmar Struve – One of the best experts on this subject based on the ideXlab platform.

Olaf Hiort – One of the best experts on this subject based on the ideXlab platform.

  • Nonisotopic single strand conformation analysis of the 5 alpha-Reductase type 2 gene for the diagnosis of 5 alpha-Reductase deficiency.
    The Journal of Clinical Endocrinology and Metabolism, 1996
    Co-Authors: Olaf Hiort, Gernot H G Sinnecker, Holger Willenbring, A. Lehners, Alfred Zollner, Dagmar Struve
    Abstract:

    5 alpha-Reductase deficiency is a rare autosomal recessive disorder of defective virilization in karyotypic males due to reduced conversion of testosterone to dihydrotestosterone. The gene encoding the affected 5 alpha-Reductase type 2 enzyme has recently been cloned, and mutations within the coding region have been discovered as the cause of this disease. We address the possibility of a rapid nonradioactive molecular genetic screening technique for initial diagnosis and report different point mutations in this gene in eight unrelated patients with clinical features of 5 alpha-Reductase deficiency. For molecular genetic analysis, DNA from peripheral blood leukocytes was studied. The coding region of the 5 alpha-Reductase type 2 gene was characterized by exon-specific PCR amplification, nonradioactive single strand conformation analysis, and direct sequencing. In seven patients, homozygous point mutations were identified (Leu55-Gln, delta Met157, Gly196-Ser, Arg227-Gln, Ala228-Thr, and His231-Arg). One ind…

  • nonisotopic single strand conformation analysis of the 5 alpha Reductase type 2 gene for the diagnosis of 5 alpha Reductase deficiency
    The Journal of Clinical Endocrinology and Metabolism, 1996
    Co-Authors: Olaf Hiort, Gernot H G Sinnecker, Holger Willenbring, A. Lehners, Alfred Zollner, Dagmar Struve
    Abstract:

    5 alpha-Reductase deficiency is a rare autosomal recessive disorder of defective virilization in karyotypic males due to reduced conversion of testosterone to dihydrotestosterone. The gene encoding the affected 5 alpha-Reductase type 2 enzyme has recently been cloned, and mutations within the coding region have been discovered as the cause of this disease. We address the possibility of a rapid nonradioactive molecular genetic screening technique for initial diagnosis and report different point mutations in this gene in eight unrelated patients with clinical features of 5 alpha-Reductase deficiency. For molecular genetic analysis, DNA from peripheral blood leukocytes was studied. The coding region of the 5 alpha-Reductase type 2 gene was characterized by exon-specific PCR amplification, nonradioactive single strand conformation analysis, and direct sequencing. In seven patients, homozygous point mutations were identified (Leu55-Gln, delta Met157, Gly196-Ser, Arg227-Gln, Ala228-Thr, and His231-Arg). One individual was a compound heterozygote carrier of two mutations (Ile112-Asn and Gln126-Arg). We conclude that molecular genetic characterization of point mutations in the 5 alpha-Reductase type 2 gene may be used as an additional valuable procedure for the diagnosis of this disorder.

Julianne Imperato-mcginley – One of the best experts on this subject based on the ideXlab platform.

Anice E. Thigpen – One of the best experts on this subject based on the ideXlab platform.

  • Cell type specific expression of steroid 5 alpha-Reductase 2.
    The Journal of urology, 1994
    Co-Authors: R I Silver, Anice E. Thigpen, E L Wiley, J M Guileyardo, J D Mcconnell, David W. Russell
    Abstract:

    Isozymes of steroid 5 alpha-Reductase (5 alpha-Reductase) have crucial roles in androgen physiology by synthesizing the potent hormone dihydrotestosterone. The expression pattern of the 5 alpha-Reductase type 2 isozyme was determined in genital and extragenital tissues by developing an immunohistochemical assay using formalin-fixed tissue and affinity purified polyclonal antibodies that specifically recognize this isozyme. Expression was detected in basal epithelial and stromal cells of the normal prostate but not in luminal epithelial cells. Stromal cells of the seminal vesicle also expressed the type 2 isozyme. In contrast, staining was detected in epithelial cells of the epididymis but not in the surrounding stroma. Myofibroblasts in foreskin samples of normal and hypospadiac individuals expressed antigen and were distributed in bands throughout the prepuce, suggesting a clonal origin. In most cells the type 2 isozyme exhibited a perinuclear subcellular distribution. However, in liver hepatocytes the protein was distributed throughout the intracellular membrane compartment.

  • Expression and regulation of steroid 5 alpha-Reductase 2 in prostate disease.
    The Journal of urology, 1994
    Co-Authors: R I Silver, David W. Russell, Anice E. Thigpen, Daphne L. Davis, E L Wiley, J D Mcconnell
    Abstract:

    The androgen dihydrotestosterone is synthesized by the enzyme steroid 5 alpha-Reductase, and it is required for growth and development of the prostate. We used immunohistochemistry to examine the expression of the type 2 isozyme of 5 alpha-Reductase in benign prostatic hyperplasia and prostate cancer. The type 2 isozyme is highly expressed within stromal cells in both disease states. No type 2 isozyme is detectable in a lymph node metastasis. Immunoblotting studies show that androgen ablation therapies substantially decrease isozyme expression in the epididymis but have a lesser effect on expression in the prostate. Finasteride therapy (2 weeks to 3 years) did not abolish expression of the prostatic type 2 isozyme nor did this drug treatment induce expression of the type 1 isozyme.

  • tissue distribution and ontogeny of steroid 5 alpha Reductase isozyme expression
    Journal of Clinical Investigation, 1993
    Co-Authors: Anice E. Thigpen, Richard I Silver, Joseph M Guileyardo, M L Casey, John D Mcconnell, David W. Russell
    Abstract:

    The synthesis of dihydrotestosterone is catalyzed by steroid 5 alpha-Reductase isozymes, designated types 1 and 2. Mutation of type 2 results in male pseupseudohermaphroditism, in which the external genitalia are phenotypically female at birth. Two striking and unexplained features of this disorder are that external genitalia of affected males undergo virilization during puberty and that these individuals have less temporal hair regression. The tissue-specific and developmental expression patterns of the 5 alpha-Reductase isozymes were investigated by immunoblotting. The type 1 isozyme is not detectable in the fetus, is transiently expressed in newborn skin and scalp, and permanently expressed in skin from the time of puberty. There was no qualitative difference in 5 alpha-Reductase type 1 expression between adult balding vs. nonbalding scalp. The type 2 isozyme is transiently expressed in skin and scalp of newborns. Type 2 is the predominant isozyme detectable in fetal genital skin, male accessory sex glands, and in the prostate, including benign prostatic hyperplasia and prostate adenocarcinoma tissues. Both isozymes are expressed in the liver, but only after birth. These results are consistent with 5 alpha-Reductase type 1 being responsible for virilization in type 2-deficient subjects during puberty, and suggest that the type 2 isozyme may be an initiating factor in development of male pattern baldness.