Ala 586 Asp mutation in androgen receptor disrupts transactivation function without affecting androgen binding.
OBJECTIVE
To understand the pathogenesis of the androgen insensitivity syndrome.


METHODS
Familial case study.


METHODS
Medical and Evolutionary Genetics Laboratory, Centre for Cellular and Molecular Biology, Hyderabad, India.


METHODS
Two affected sisters and other unaffected family members.


METHODS
The hormone levels were measured by RIA. Histology was done by standard protocols. DNA isolation and direct DNA sequencing was undertaken for mutation identification. Site-directed mutagenesis was used for incorporation of mutation in the androgen receptor clone. Functional assays were done using COS-1 cell cultures.


METHODS
Phenotype, hormone levels, DNA mutations, ligand binding, transactivation function of androgen-androgen receptor complex.


RESULTS
The patients exhibited a female phenotype despite the 46,XY chromosome complement. Both of the affected individuals had higher levels of T and LH. C1760A (coding DNA sequence reference) substitution (Ala 586 Asp) in the AR gene was observed in all of the affected individuals. The mutation did not result in a loss of ligand binding but instead in almost complete loss of transactivation function.


CONCLUSIONS
The Ala 586 Asp mutation resulted in a complete loss of transactivation function of the androgen-androgen receptor complex but did not affect ligand binding. In vitro assays confirmed the pathogenic nature of this mutation.
Rajender
Singh
S
Centre for Cellular and Molecular Biology, Hyderabad, India. thangs@ccmb.res.in
Gupta
Nalini J
NJ
Chakrabarty
Baidyanath
B
Singh
Lalji
L
Thangaraj
Kumarasamy
K
D000595:Amino Acid Sequence; D013734:Androgen-Insensitivity Syndrome / Q000235:genetics* / Q000378:metabolism / Q000473:pathology; D000728:Androgens / Q000097:blood*; D000818:Animals; D019556:COS Cells; D002522:Chlorocebus aethiops; D004252:DNA Mutational Analysis; D005260:Female; D043373:Follicle Stimulating Hormone, Human / Q000097:blood; D020022:Genetic Predisposition to Disease; D006801:Humans; D007621:Karyotyping; D007986:Luteinizing Hormone / Q000097:blood; D008297:Male; D008969:Molecular Sequence Data; D016297:Mutagenesis, Site-Directed; D009154:Mutation; D010375:Pedigree; D010641:Phenotype; D011944:Receptors, Androgen / Q000235:genetics* / Q000378:metabolism; D013739:Testosterone / Q000097:blood; D015533:Transcriptional Activation; D014162:Transfection; D055815:Young Adult
C410798:AR protein, human; D000728:Androgens; D043373:Follicle Stimulating Hormone, Human; D011944:Receptors, Androgen; D013739:Testosterone; D007986:Luteinizing Hormone