cytidylyl-3--5--guanosine and Immunologic-Deficiency-Syndromes

Topics: Chromosome Mapping; Chromosomes, Artificial, Yeast; Dinucleoside Phosphates; DNA; Dosage Compensation, Genetic; Exons; Female; Genetic Linkage; Humans; Immunologic Deficiency Syndromes; Male; X Chromosome

Topics: Animals; Centromere; Chromosome Aberrations; Chromosome Disorders; CpG Islands; Dinucleoside Phosphates; DNA (Cytosine-5-)-Methyltransferase 1; DNA (Cytosine-5-)-Methyltransferases; DNA Methylation; DNA Methyltransferase 3A; DNA Methyltransferase 3B; DNA, Satellite; Drosophila; Embryonic and Fetal Development; Face; Humans; Immunologic Deficiency Syndromes; Mice; Mice, Knockout; Stem Cells; Syndrome

We developed an X chromosome inactivation PCR assay, based on differential methylation of the 5' CpG island of the monoamine oxidase A gene (MAOA), close to a highly polymorphic region just downstream of the first exon. The assay provides a method to determine the carrier status of females from pedigrees with X-linked immunodeficiency diseases (XLID).

Topics: Agammaglobulinemia; Chromosome Mapping; Dinucleoside Phosphates; Dosage Compensation, Genetic; Exons; Female; Genetic Carrier Screening; Genetic Linkage; Humans; Immunologic Deficiency Syndromes; Male; Methylation; Monoamine Oxidase; Polymerase Chain Reaction; Severe Combined Immunodeficiency; Wiskott-Aldrich Syndrome; X Chromosome

The differential methylation of a CpG island 2.5 kb distant from a hypervariable region at the DXS255 locus provides the basis for a Southern blotting X chromosome inactivation analysis system. The technique enables carrier detection in about 90% of females at risk from pedigrees with Wiskott-Aldrich syndrome, X-linked severe combined immunodeficiency or X-linked agammaglobulinemia.

Topics: Agammaglobulinemia; Chromosome Mapping; Dinucleoside Phosphates; Dosage Compensation, Genetic; Female; Genetic Carrier Screening; Genetic Linkage; Humans; Immunologic Deficiency Syndromes; Male; Methylation; Repetitive Sequences, Nucleic Acid; Severe Combined Immunodeficiency; Wiskott-Aldrich Syndrome; X Chromosome

We have identified a previously unrecognized missense mutation in a patient with severe combined immunodeficiency due to adenosine deaminase deficiency (ADA-SCID). The mutation is a G646-to-A transition at a CG dinucleotide and predicts a glycine-to-arginine substitution at codon 216. Computer analysis of secondary structure predicts a major alteration with loss of a beta-pleated sheet in a highly conserved region of the protein. The basepair substitution also generates a new site for the restriction enzyme BstXI in exon 7 of the genomic DNA. Digestion of genomic DNA from the patient and from his parents revealed that he was homozygous for the mutation and that his mother and father were carriers. This mutation in homozygous form appears to be associated with very severe disease, since the patient had perinatal onset of clinical manifestations of SCID, the highest concentration of the toxic metabolite deoxyATP in nine patients studied, and a relatively poor immunologic response during the initial 2 years of therapy with polyethylene glycol-adenosine deaminase. Analysis of DNA from 21 additional patients with ADA-SCID and from 19 unrelated normals revealed that, while none of the normal individuals showed the abnormal restriction fragment, two of the 21 patients studied were heterozygous for the G646-to-A mutation.

Topics: Adenosine Deaminase; Base Composition; Cell Line, Transformed; Chromosome Deletion; Deoxyribonucleases, Type II Site-Specific; Dinucleoside Phosphates; Erythrocytes; Exons; Heterozygote; Homozygote; Humans; Immunologic Deficiency Syndromes; Infant, Newborn; Male; Mutation; Polymorphism, Restriction Fragment Length; Protein Conformation