Table 2.

X-linked genes found to be overexpressed in females in at least 3 of 11 tissues

Symbol	Chromosome band	Carrel and Willard [2]	Adrenal	Cerebrum	Colon	Ileum	Kidney	Liver	Lung	Sk muscle	Spleen	Stomach	Ureter
HDHD1A	Xp22.32	8/9	1.8 *	1.5	1.2	1.2	1.9*	1.4*	1.4	1.1	1.6*	1.3	1.2
PNPLA4	Xp22.3	9/9	1.8*	1.1	1.1	1.0	1.3	1.6*	1.1	0.8	1.1	1.8*	1.2
AP1S2	Xp22.2	9/9	1.4	1.3	1.1	0.9	1.5	1.3	1.1	0.9	1.5	0.8	1.5
ZFX	Xp21.3	9/9	0.9	1.0	1.5*	1.1	1.3	1.8*	1.5	1.2	1.5*	1.4*	1.3
RPGR	Xp11.4	0/9	0.9	1.0	1.4	1.6	1.2	1.1	1.4	1.5	1.3*	0.9	1.6
UTX	Xp11.2	Escapes inactivation a	1.0	0.9	1.8*	1.2	1.7*	1.6*	1.8*	1.3*	1.4*	1.7*	1.3
RPS4X	Xq13.1	9/9	1.2	1.1	1.7*	1.0	1.7*	1.7	1.4	1.1	1.3	1.2	1.0
ACSL4	Xq22.3	0/5	1.5	1.7*	0.9	1.0	1.5	6.6	1.6	0.9	1.4	1.2	1.2
CDR1	Xq27.1	2/9	0.9	2.0	0.9	1.0	1.2	1.0	1.6*	1.0	1.1	1.6	0.9
		Total	3	3	3	1	5	5	4	1	2	3	2
			33%	33%	33%	11%	56%	56%	44%	11%	33%	33%	22%

At least 3 of 11 tissues showed gene overexpression in females (≥ 1.5 F/M gene fold ratios), indicating escape from inactivation for the X-linked gene. Of the nine X-linked genes with evidence of escaping X inactivation, six are located on the short arm and three on the long arm. Six of the nine genes were also reported to have escaped X inactivation by Carrel and Willard [2] (e.g., expressed from the inactive X in 8/9 or 9/9 cell hybrids) and Greenfield et al. [6].

^aGreenfield et al. [6].

^*F/M gene fold ratios indicating significantly higher expression in females than in males (t test; p<0.05).