A fourth gene involved in a form of oculo-pharyngo-distal myopathy, OPDM type 4

Chinese researchers have identified a new gene responsible for an ultra-rare form of oculo-pharyngo-distal myopathy. It joins three other genes, LRP12, GIPC1 and NOTCH2NLC, which have in common that they are linked to the same pathological nucleotide expansion of the CGG type. The RILPL1 gene:

  • was identified through the study, by sequencing of long fragments, of two cases (one familial, the other sporadic) negative for the other genes of oculo-pharyngo-distal myopathy (OPDM) and then by screening other patients with OPDM,
  • also codes for a CGG-like expansion, with a number of repetitions varying from 139 to 197.

The authors point out that the expansion is always found in the untranslated 5′ part of each of the four incriminated genes, thus suggesting a pathophysiological mechanism common to all OPDMs.

 

The CGG repeat expansion in RILPL1 is associated with oculopharyngodistal myopathy type 4. Yu J, Shan J, Yu M, et al. Am J Hum Genet. 2022 Mar 3;109(3):533-541.