A study using a research strategy that combined linkage analysis, whole-exome sequencing, long-read whole-genome sequencing, repeat-primed polymerase chain reaction, and GC-rich polymerase chain reaction, in 197 Chinese pedigrees with ET, identified in 11 of them (co-segregating with the disease) an abnormal CGG repeat expansion in the 5′ region of the Notch 2 N-terminal-like gene (NOTCH2NLC or ETM6, chromosome 1q21.2, MIM 618025, Gene ID 100996717, mutations in this gene are associated with neuronal intranuclear inclusion disease, or NIID) [113]. Here, NOTCH2NLC is linked to essential thrombocythemia.