Point mutations detected in the androgen receptor gene of three men with partial androgen insensitivity syndrome.

2.50
Hdl Handle:
http://hdl.handle.net/10541/109518
Title:
Point mutations detected in the androgen receptor gene of three men with partial androgen insensitivity syndrome.
Authors:
Saunders, P T; Padayachi, T; Tincello, D G; Shalet, Stephen M; Wu, F C
Abstract:
OBJECTIVE: Determine the sequence of the androgen receptor gene in men with impaired responsiveness to androgens in order to identify the molecular basis of their under-virilization. DESIGN: Blood samples were used as the source of genomic DNA. Portions of the androgen receptor gene were amplified by polymerase chain reaction and sequenced. PATIENTS: Samples were obtained from three patients and five normal fertile controls. Patients were all 46 XY and were undervirilized with ambiguous external genitalia, gynaecomastia and infertility. MEASUREMENTS: Total cellular DNA was purified from peripheral blood leucocytes. Pairs of oligonucleotide primers designed to flank the individual exons of the androgen receptor gene were synthesized. The specific regions of the androgen receptor were amplified from the samples of cellular DNA by polymerase chain reaction. Amplified DNA was purified, sequenced and compared to the published sequence. RESULTS: In all three patients point mutations in the androgen receptor gene were detected but no defects were detected in samples from normal controls. In two of the patients, an identical single nucleotide change from G to T was detected. This nucleotide was within the codon for amino acid 866 and would change it from valine to leucine. Amino acid 866 is found within an area of the steroid binding domain thought to be involved in receptor dimerization. Within the repetitive sequence of exon I patient 1 had 21 glutamine residues and patient 2 had 25. In the third patient a single change of G to A would result in incorporation of lysine in place of a conserved arginine residue at position 607 within the second zinc finger of the DNA binding domain. The sequence of the androgen receptor gene of the mother of the third patient revealed her to be heterozygous for the same defect. CONCLUSION: Patients 1 and 2 are unrelated although they have an identical point mutation in their androgen receptor gene. A patient with complete androgen insensitivity syndrome has been reported to have a defect at the same position causing the amino acid substitution of methionine for valine. Therefore we confirm that the nature of the amino acid change in the peptide sequence of the androgen receptor as well as its location within the protein, can have a profound effect on the phenotypic severity of androgen resistance. Studies on mutated receptors from individuals with a wide range of degrees of androgen resistance may enable us to construct a map of the key amino acids in the different domains of the protein.
Affiliation:
MRC Reproductive Biology Unit, Edinburgh, UK.
Citation:
Point mutations detected in the androgen receptor gene of three men with partial androgen insensitivity syndrome. 1992, 37 (3):214-20 Clin Endocrinol
Journal:
Clinical Endocrinology
Issue Date:
Sep-1992
URI:
http://hdl.handle.net/10541/109518
DOI:
10.1111/j.1365-2265.1992.tb02313.x
PubMed ID:
1424203
Type:
Article
Language:
en
ISSN:
0300-0664
Appears in Collections:
All Christie Publications

Full metadata record

DC FieldValue Language
dc.contributor.authorSaunders, P Ten
dc.contributor.authorPadayachi, Ten
dc.contributor.authorTincello, D Gen
dc.contributor.authorShalet, Stephen Men
dc.contributor.authorWu, F Cen
dc.date.accessioned2010-08-11T16:48:59Z-
dc.date.available2010-08-11T16:48:59Z-
dc.date.issued1992-09-
dc.identifier.citationPoint mutations detected in the androgen receptor gene of three men with partial androgen insensitivity syndrome. 1992, 37 (3):214-20 Clin Endocrinolen
dc.identifier.issn0300-0664-
dc.identifier.pmid1424203-
dc.identifier.doi10.1111/j.1365-2265.1992.tb02313.x-
dc.identifier.urihttp://hdl.handle.net/10541/109518-
dc.description.abstractOBJECTIVE: Determine the sequence of the androgen receptor gene in men with impaired responsiveness to androgens in order to identify the molecular basis of their under-virilization. DESIGN: Blood samples were used as the source of genomic DNA. Portions of the androgen receptor gene were amplified by polymerase chain reaction and sequenced. PATIENTS: Samples were obtained from three patients and five normal fertile controls. Patients were all 46 XY and were undervirilized with ambiguous external genitalia, gynaecomastia and infertility. MEASUREMENTS: Total cellular DNA was purified from peripheral blood leucocytes. Pairs of oligonucleotide primers designed to flank the individual exons of the androgen receptor gene were synthesized. The specific regions of the androgen receptor were amplified from the samples of cellular DNA by polymerase chain reaction. Amplified DNA was purified, sequenced and compared to the published sequence. RESULTS: In all three patients point mutations in the androgen receptor gene were detected but no defects were detected in samples from normal controls. In two of the patients, an identical single nucleotide change from G to T was detected. This nucleotide was within the codon for amino acid 866 and would change it from valine to leucine. Amino acid 866 is found within an area of the steroid binding domain thought to be involved in receptor dimerization. Within the repetitive sequence of exon I patient 1 had 21 glutamine residues and patient 2 had 25. In the third patient a single change of G to A would result in incorporation of lysine in place of a conserved arginine residue at position 607 within the second zinc finger of the DNA binding domain. The sequence of the androgen receptor gene of the mother of the third patient revealed her to be heterozygous for the same defect. CONCLUSION: Patients 1 and 2 are unrelated although they have an identical point mutation in their androgen receptor gene. A patient with complete androgen insensitivity syndrome has been reported to have a defect at the same position causing the amino acid substitution of methionine for valine. Therefore we confirm that the nature of the amino acid change in the peptide sequence of the androgen receptor as well as its location within the protein, can have a profound effect on the phenotypic severity of androgen resistance. Studies on mutated receptors from individuals with a wide range of degrees of androgen resistance may enable us to construct a map of the key amino acids in the different domains of the protein.en
dc.language.isoenen
dc.subject.meshAdult-
dc.subject.meshAmino Acid Sequence-
dc.subject.meshAndrogen-Insensitivity Syndrome-
dc.subject.meshDNA-
dc.subject.meshDNA Mutational Analysis-
dc.subject.meshExons-
dc.subject.meshHumans-
dc.subject.meshMale-
dc.subject.meshMolecular Sequence Data-
dc.subject.meshMutation-
dc.subject.meshPolymerase Chain Reaction-
dc.subject.meshReceptors, Androgen-
dc.titlePoint mutations detected in the androgen receptor gene of three men with partial androgen insensitivity syndrome.en
dc.typeArticleen
dc.contributor.departmentMRC Reproductive Biology Unit, Edinburgh, UK.en
dc.identifier.journalClinical Endocrinologyen

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