Overview of repeats
A disease named oculopharyngeal myopathy with leukoencephalopathy 1 (OPML1) has been described by Ishiura and colleagues in 2019 which was characterised in one family. Expansion of CCG repeats was observed in the NUTM2B-AS1 gene that is transcribed bidirectionally (in CGG direction) in the noncoding RNA LOC642361 gene. In one out of four patients, the expanded allele was determined to be 2.1 kb which corresponds to 700 trinucleotide repeats. In controls the repeat range was between 3 to 16 repeats (Ishiura et al., 2019).