Familial glucocorticoid resistance is a hypertensive, hyperandrogenic disorder characterized by increased serum cortisol concentrations in the absence of stigmata of Cushing's syndrome. Our previous studies of the first reported kindred showed a two-to threefold reduction in glucocorticoid receptorligand binding affinity in the propositus, and a lesser reduction in affinity in his mildly affected son and nephew. Glucocorticoid receptor cDNA from these three patients was amplified by polymerase chain reaction and sequenced. The cDNA nucleotide sequence was normal, except for nucleotide 2054, which substituted valine for aspartic acid at amino acid residue 641. The propositus was homozygous while the other relatives were heterozygous for the mutation. COS-7 monkey kidney cells were cotransfected with expression vectors for either wild type or Val 641-mutant receptors, together with the reporter plasmid pMMTV-CAT. Dexamethasone increased chloramphenicol acetyltransferase activity in cells expressing wild type receptor, but had no effect in cells expressing Val 641-mutant receptors, despite similar receptor concentrations, as indicated by Western blotting. The binding affinity for dexamethasone of the Val 641-mutant receptor was threefold lower than that of the wild type receptor. These results suggest that glucocorticoid resistance in this family is due to a point mutation in the steroidbinding domain of the glucocorticoid receptor. (J. Clin. Invest.

An essential property of the immune system is its ability to generate great diversity in antibody and T-cell immune responses. The genetic and molecular mechanisms responsible for the generation of antibody diversity have been investigated during the past several years. The gene for the variable (V) region, which determines antigen specificity, is assembled when one member of each of the dispersed clusters of V gene segments, diversity (D) elements (for heavy chains only) and joining (J) segments are fused by DNA rearrangement. The cloning of the beta-chain of the T-cell antigen receptor revealed that the organization of the beta-chain locus, which is similar to that of immunoglobulin genes, is also composed of noncontiguous segments of V, D, J and constant (C) region genes. The structure of the alpha-chain seems to consist of a V and a C domain connected by a J segment. We report here that the human T-cell receptor alpha-chain gene consists of a number of noncontiguous V and J gene segments and a C region gene. The V region gene segment is interrupted by a single intron, whereas the C region contains four exons. The J segments, situated 5' of the C region gene, are dispersed over a distance of at least 35 kilobases (kb). Signal sequences, which are presumably involved in DNA recombination, are found next to the V and J gene segments.

The humoral immune system antigen-binding proteins (immunoglobulins) are disulphide-linked heterodimers of light and heavy chains. The gene for the variable region which determines antigen specificity is assembled when one member from each of the dispersed clusters of variable (V) gene segments, diversity (D) elements (for the heavy chains only) and joining (J) segments rearrange and fuse during B-cell development (reviewed in ref. 1). Short recognition sequences adjacent to these elements appear to be involved in the recombination process. The cellular immune system antigen recognition proteins are receptors on the surface of T cells, which are composed of disulphide-linked alpha-chains and beta-chains, each of which has a variable and constant region. Recently, cDNA clones of the beta-chain mRNA have been isolated; the genomic arrangement is very similar to immunoglobulin genes with multiple V beta genes, and two clusters of J beta segments, each of which is upstream from a constant-region gene segment. The V beta and J beta segments have adjacent recombinational recognition sequences like the immunoglobulin elements. However, approximately 10 nucleotides of the cDNA clones between the V beta and J beta regions were not present in the corresponding genomic elements and may have been due to intervening D beta segments. Here we describe a diversity element (D beta 1.1) in a region of high human-mouse homology about 650 bases 5' to the first J beta cluster. Two transcripts which include sequences upstream of D beta 1.1 are found in the human thymus. This region may have some other function besides providing the beta-chain with a diversity segment.