Table 1. Characterization of the four X-chromosomal escape genes corresponding to differentially methylated positions with a FWER < 0.05.

HGNC symbol	Function	Diseases
USP9X	Member of the peptidase C19 family. Encodes a protein that is similar to ubiquitin-specific proteases. Known to escape X-inactivation. Mutations in this gene have been associated with Turner syndrome. It has been suggested that USP9X mutations cause changes in the neuronal cytoskeleton, which may affect neuronal migration and axonal growth, resulting in intellectual disability. [http://www.omim.org/entry/300072?search=USP9X&highlight=usp9x]	Turner syndrome, X-linked recessive nonsyndromic mental retardation
UBA1	First step in ubiquitin conjugation to mark cellular proteins for degradation. [http://www.omim.org/entry/314370? search=UBA1&highlight=uba1]	X-linked infantile spinal muscular atrophy?
STS	Catalyzes the conversion of sulfated steroid precursors to estrogen	X-linked ichthyosis
KDM6A	Known Y homolog gene. KDM6A encodes a tetratricopeptide repeat (TPR) protein. The encoded protein contains a JmjC-domain and catalyzes the demethylation of tri/dimethylated histone H3. Known escape gene. Importance for reestablishment of pluripotency and germ cell development	Kabuki Syndrome 2