Dissecting phenotypic variation among AIS patients

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Abstract

We have created genital skin fibroblast cell lines directly from three patients in a Chinese family affected by androgen insensitivity syndrome (AIS). All patients in the family share an identical AR Arg840Cys mutant but show different disease phenotypes. By using the cell lines, we find that the mutation has not influenced a normal androgen-binding capacity at 37 °C but has reduced the affinity for androgens and may cause thermolability of the androgen–receptor complex. The impaired nuclear trafficking of the androgen receptor in the cell lines is highly correlated with the severity of donors’ disease phenotype. The transactivity of the mutant is substantially weakened and the extent of the reduced transactivity reflects severity of the donors’ disease symptom. Our data reveal that although etiology of AIS is monogenic and the mutant may alter the major biological functions of its wild allele, the function of the mutant AR can also be influenced by the different genetic backgrounds and thus explains the divergent disease phenotypes.

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Materials and methods

Family and patients. A large Chinese family, which consisted of a total of 132 members across five generations, 14 males of them affected with AIS, was described in our previous genetic analysis. It showed that the patients in the pedigree shared an identical Arg840Cys substitution in the androgen receptor but displayed divergent disease phenotypes [12]. The patients who donated their genital skin tissues for the present study included the proband IV54 (cell strain MJ), who was fertile but was

Expression of AR in GSF cell lines

Fig. 1 shows Northern (A) and Western (B) blotting assays of AR in the GSF cell lines from the three AIS patients in the same family and from one independent normal donor. It does not reveal any viewable change in both transcriptional and translational levels of the AR gene among the four cell lines (N, MJ, YS, and ZGJ). The data first exclude the possibility of ascribing the divergent disease phenotypes of the three patients to any variation in the mRNA and protein levels of the mutant that

Discussion

There have been more than 300 mutations in the human androgen receptor gene [22]. Understanding the genetic effects of these mutants on the development of human maleness has been one of the active areas in human molecular genetics and reproductive physiology [20], [23], [24]. Many studies have focused on correlating the different mutants to different disease phenotypes of androgen insensitivity syndrome, based either on a few sporadic cases and/or on exogenous, such as COS or CV1, cells.

Acknowledgment

We are grateful to the patients for their participation and cooperation in the present study.

References (27)

  • G. Buchanan et al.

    Collocation of androgen receptor gene mutations in prostate cancer

    Clin. Cancer Res.

    (2001)
  • K.J. Greenland et al.

    Polymorphic CAG repeat length in the androgen receptor gene and association with neurodegeneration in a heterozygous female carrier of Kennedy’s disease

    J. Neurol.

    (2004)
  • C.A. Quigley et al.

    Androgen receptor defects: historical, clinical, and molecular perspectives

    Endocr. Rev.

    (1995)
  • Cited by (6)

    The research was supported in part by grants from China’s Key Basic Research Program (“973”) and China’s National Natural Science Foundation. Z.W.L. is also supported by research grants from the Medical Research Committee of the University of Birmingham, BBSRC, and NERC.

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