X Chromosome Inactivation in Opioid Addicted Women

introduction: x chromosome inactivation (xci) is a process during which one of the two xchromosomes in female human is silenced leading to equal gene expression with males whohave only one x chromosome. here we have investigated xci ratio in females with opioidaddiction to see whether xci skewness in women could be a risk factor for opioid addiction. methods: 30 adult females meeting dsm iv criteria for opioid addiction and 30 control femaleswith no known history of addiction were included in the study. digested and undigested dnasamples which were extracted from blood were analyzed after amplification of the polymorphicandrogen receptor (ar) gene located on the x chromosome. xci skewness was studied in 3ranges: 50:50–64:36 (random inactivation), 65:35–80:20 (moderately skewed) and >80:20(highly skewed). results: xci from informative females in control group was 63% (n=19) random, 27% (n=8)moderately skewed and 10% (n=3) highly skewed. addicted women showed 57%, 23% and20%, respectively. the distribution and frequency of xci status in women with opioid addictionwas not significantly different from control group (p=0.55). discussion: our data did not approve our hypothesis of increased xci skewness among womenwith opioid addiction or unbalanced (non-random) expression of genes associated with xchromosome in female opioid addicted subjects.