Report of the committee on the genetic constitution of the X and Y chromosomes

Chromosomal localization of ZFX—A human gene that escapes X inactivation—and its murine homologs

“…While most genes on the X chromosome are presumed to be subject to such inactivation, transcriptional analysis reveals that the human ZFX gene escapes X in- activation (Schneider-Giidicke et ol., 1989a). Three other X-linked genes (XC, STS, and MIC2) had been shown to escape X inactivation (Fialkow, 1970;Race and Sanger, 1975;Shapiro et al, 1979;Mohandas et al, 1980;Migeon et al, 1982;Goodfellow et al, 1984), but all map to the extreme distal portion of the short arm of the human X chromosome (band Xp22.3; reviewed by Davies et al, 1987). These earlier observations had suggested that a single, discrete portion of Xp escapes X inactivation.…”

“…As judged by transcriptional analysis of cell lines, the human ZFX gene escapes X inactivation (SchneiderGiidicke et al, 1989a). The few other genes known to 37 escape X inactivation have all been mapped to the most distal portion of the X-chromosome short arm (e.g., Xp22.3), fostering the notion of a single, discrete portion of Xp that escapes X inactivation (Fialkow, 1970;Race and Sanger, 1975;Shapiro et al, 1979;Mohandas et al, 1980;Migeon et al, 1982;Goodfellow et al, 1984; localizations reviewed by Davies et al, 1987).…”

Mapping the gene causing X-linked recessive idiopathic hypoparathyroidism to Xq26-Xq27 by linkage studies.

“…The details of these probes and references are given by Davies et al (17). The Southern blot was hybridized as described previously (18).…”

“…These calculations were performed using the computer programs MLINK and ILINK (19) from LINKAGE (version 4.7). The frequency of idiopathic hypoparathyroidism was estimated to be I0-', and the RFLP allele frequencies used were previously published values (17). Varying the disease frequency had no effect on the results of the linkage analysis.…”

“…The fixed framework ofmarkers required for multilocus linkage analysis was deduced from previously published genetic maps (17,(20)(21)(22)(23)(24)(25)(26). Calculations of genetic distances for multilocus analysis were performed by converting published recombination frequencies (6) to genetic distances (d) with Haldane's mapping function, d = -0.5 In (1 -26), which assumes no interference.…”