"RNU2-2" syndrome is a neurodevelopmental disorder caused by "de novo" variants in the human gene "RNU2-2", which encodes an RNA component of the major spliceosome. It is characterized by epilepsy, intellectual disability, autistic behavior, microcephaly, hypotonia and hyperventilation. 
The syndrome is an autosomal dominant genetic disorder caused by "de novo" variants in "RNU2-2", a gene on chromosome 11, which encodes the small nuclear RNA (snRNA) U2. U2 is a component of the major spliceosome, a complex of proteins and non-coding RNAs that is necessary for RNA splicing. Most cases of "RNU2-2" syndrome are explained by the single nucleotide variants n.4G>A, n.35A>G, in roughly equal proportions. n.4G>A is thought to disrupt the interactions of snRNA U2 with the snRNA U6. n.35A>G is thought to disrupt the interaction of snRNA U2 with the 3′ branch sites of introns.
"RNU2-2" syndrome was discovered by the statisticians Daniel Greene and Ernest Turro at the Icahn School of Medicine at Mount Sinai, using a Bayesian approach applied to data generated by Genomics England. The same team were one of two groups to previously discover ReNU syndome, a related disorder caused by "de novo" variants in "RNU4-2," that is 5 times more prevalent, using the same approach.