X chromosome inactivation (XCI) is a process that occurs during the embryonic development by which mammalian female cells have one of the two X chromosomes inactivated. Chromosome X inactivation is believed to be random in early female development. The X inactivation ratios of females can range from a highly skewed ratio 0:100, where the same X chromosome is active for all cells, to a 50:50 ratio, where each X chromosome is active in an equal number of cells.The present work aimed to study the X chromosome inactivation patterns in cases with abnormal X chromosome and to correlate these different patterns with the patient’s phenotype.