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A detailed genotype-phenotype evaluation is presented by studying the enzyme activities of five rare amino acid substitutions (Arg233Gly, Ala265Ser, Arg341Trp, Arg366Cys and Met473Ile) identified in the CYP21A2 gene in patients investigated for Congenital adrenal hyperplasia (CAH).To investigate whether the mutations identified in the CYP21A2 gene are disease causing and to establish a gradient for the degree of enzyme impairment to improve prediction of patient phenotype.The CYP21A2 genes of seven patients investigated for CAH were sequenced and five mutations were identified. The mutant proteins were expressed in vitro in COS-1 cells, and the enzyme activities towards the two natural substrates were determined to verify the disease-causing state of the mutations. The in vitro activities of these rare mutations were also compared with the activities of four mutations known to cause nonclassic CAH (Pro30Leu, Val281Leu, Pro453Ser and Pro482Ser) in addition to an in silico structural evaluation of the novel mutants.To verify the disease-causing state of novel mutations.Five CYP21A2 mutations were identified (Arg233Gly, Ala265Ser, Arg341Trp, Arg366Cys and Met473Ile). All mutant proteins exhibited enzyme activities above 5%, and four mutations were classified as nonclassic and one as a normal variant. By comparing the investigated protein changes with four common mutations causing nonclassic CAH, a gradient for the degree of enzyme impairment could be established. Studying rare mutations in CAH increases our knowledge regarding the molecular mechanisms that render a mutation pathogenic. It also improves phenotype predictions and genetic counselling for future generations.

OBJECTIVE: Resistance to androgens has been suggested as a possible cause of male infertility. This hypothesis is based mainly on binding studies in genital skin fibroblasts but the molecular evidence is sparse. DESIGN: Molecular studies of the androgen receptor gene were performed in 10 azoo- or oligozoospermic men, precenting with clinical signs of low androgen activity - poor virilization and high serum LH despite elevated testosterone levels, but without genitel malformations. PATIENTS: Ten men with serum LH >10 IU/l and testosterone >30 nmol/l as well as a low sperm concentration

OBJECTIVE The development and progression of sporadic adrenocortical tumours are poorly understood. In autopsy studies adrenocortical tumours are found in between 2 and 9% of the general population. In congenital adrenal hyperplasia (CAH), decreased production of cortisol leads to increased secretion of ACTH from the pituitary, resulting in hyperplasia of the adrenals. More than 95% of all cases of CAH are due to steroid 21-hydroxylase deficiency, resulting from mutations in the CYP21 gene. In subjects homozygous and heterozygous for CYP21 mutations, adrenocortical tumours have been found in a high frequency compared to the general population, suggesting that chronic ACTH stimulation may play a role in the development of this tumour form. In order to test whether mild undiagnosed CAH is a common predisposing factor, we screened 27 patients with sporadic adrenocortical tumours for CYP21 mutations. DESIGN A retrospective study. PATIENTS We screened 27 patients with sporadic adrenocortical tumours, representing both benign and malignant as well as hormonally active and silent lesions. MEASUREMENTS Mutation analyses of the CYP21 gene was performed by allele-specific PCR on high molecular weight DNA. The method used detects the nine CYP21 mutations that are responsible for 95% of all disease-causing alleles in CAH. RESULTS No mutations were detected in any of the 23 DNA samples that were prepared from leucocytes. In 4 cases where no leucocyte DNA was available, tumour tissue was analysed. In one of these tumours, two CYP21 mutations, V281 L and L307insT, were found in heterozygous form. CONCLUSION Our data indicate that mild undiagnosed congenital adrenal hyperplasia is not a common underlying factor predisposing to adrenocortical tumours, at least not in the Swedish population.

BACKGROUND: The androgen receptor (AR) is essential for the differentiation of male external and internal genitalia. It is normally present in two forms, a full-length form B and an N-terminal truncated form A with still unknown function. Mutations in the AR gene cause androgen insensitivity syndrome (AIS), which is divided into subgroups according to the degree of undermasculinization. Patients with completely female external genitalia are classified as complete AIS (CAIS). However, a recent study has shown that some CAIS patients have signs of internal male genital differentiation due to missense mutations that show some degree of residual function. OBJECTIVE: We aimed to study the expression of the different forms of the AR in two CAIS patients in relation to the development of male internal genital structures. One patient had a mutation (L7fsX33) that affects only the full-length AR-B form of the AR, whereas the other had a nonsense mutation (Q733X) affecting both isoforms. MEASUREMENTS AND RESULTS: We thoroughly analysed internal genitalia at surgery and by histological examination. No signs of Wolffian duct (WD) development were present in any of the patients. Western blotting of proteins from gonadal and genital skin fibroblasts was performed with AR antibodies directed against different AR epitopes. The N-terminally truncated A form was expressed in normal amounts in the patient with the L7fsX33 mutation while no AR was detected in the other patient. CONCLUSION: The presence of the AR-A form does not seem to be sufficient for WD maintenance and differentiation.

Resistance to androgens has been suggested as a possible cause of male infertility. This hypothesis is based mainly on binding studies in genital skin fibroblasts but the molecular evidence is sparse.Molecular studies of the androgen receptor gene were performed in 10 azoo- or oligozoospermic men, presenting with clinical signs of low androgen activity-poor virilization and high serum LH despite elevated testosterone levels, but without genital malformations.Ten men with serum LH10 IU/l and testosterone30 nmol/l as well as a low sperm concentration20 x 106/ml.Genomic DNA was prepared from peripheral leucocytes and PCR-amplification of the coding region of androgen receptor was performed, followed by direct sequencing. Identified mutations were reconstructed by site-directed mutagenesis and the functional properties of the mutants were analysed, using transient expression in COS-1 cells and subsequent transactivation assays. Hormone binding assays were performed in genital skin fibroblasts from the patients.Two of the 10 men were shown to have a mutation in the androgen receptor gene. Subject 1, who presented with azoospermia, serum testosterone (T) 50 nmol/l and LH 20 IU/l, had a mutation in exon 1, changing amino acid asparagine 233 to lysine (N233K). In fibroblasts cultured from genital skin, the receptor affinity for 5alpha-dihydrotestosterone (DHT) was normal as compared to healthy controls, but the receptor-hormone complex was thermolabile at 42 degrees C. Subject 2 exhibited severe oligozoospermia and a similar endocrine pattern (T = 50 nmol/l and LH = 25 IU/l). He had a mutation in exon 5 changing asparagine 756 to serine (N756S). The affinity for DHT in cultured genital fibroblasts from this patient was reduced. Transactivation was abnormal for both mutants, N233K reaching 46% and N756S 38% of wild type activity when stimulated with 10 nmol/l DHT.Androgen receptor mutations may affect sperm production without resulting in genital malformations. Thus, in infertile men with a clinical presentation of poor androgen activity and an endocrine profile compatible with androgen resistance, mutations in the androgen receptor should be taken into consideration.

The development and progression of sporadic adrenocortical tumours are poorly understood. In autopsy studies adrenocortical tumours are found in between 2 and 9% of the general population. In congenital adrenal hyperplasia (CAH), decreased production of cortisol leads to increased secretion of ACTH from the pituitary, resulting in hyperplasia of the adrenals. More than 95% of all cases of CAH are due to steroid 21-hydroxylase deficiency, resulting from mutations in the CYP21 gene. In subjects homozygous and heterozygous for CYP21 mutations, adrenocortical tumours have been found in a high frequency compared to the general population, suggesting that chronic ACTH stimulation may play a role in the development of this tumour form. In order to test whether mild undiagnosed CAH is a common predisposing factor, we screened 27 patients with sporadic adrenocortical tumours for CYP21 mutations.A retrospective study.We screened 27 patients with sporadic adrenocortical tumours, representing both benign and malignant as well as hormonally active and silent lesions.Mutation analyses of the CYP21 gene was performed by allele-specific PCR on high molecular weight DNA. The method used detects the nine CYP21 mutations that are responsible for 95% of all disease-causing alleles in CAH.No mutations were detected in any of the 23 DNA samples that were prepared from leucocytes. In 4 cases where no leucocyte DNA was available, tumour tissue was analysed. In one of these tumours, two CYP21 mutations, V281 L and L307insT, were found in heterozygous form.Our data indicate that mild undiagnosed congenital adrenal hyperplasia is not a common underlying factor predisposing to adrenocortical tumours, at least not in the Swedish population.