Clinical exome sequencing identifies novel compound heterozygous mutations of the POMT2 gene in patients with limb-girdle muscular dystrophy

Objective: Mutations in protein O-mannosyltransferase 2 (POMT2) (MIM#607439) have been identified in severe congenital muscular dystrophy such as Walker-Warburg syndrome (WWS) and milder limb-girdle muscular dystrophy type 2N (LGMD2N). The aim of this study is to investigate the genetic causes in patients with LGMD2N.

Methods: Three patients diagnosed with mild limb-girdle muscular dystrophy were recruited. The genetically pathogenic variant was identified by clinical exome sequencing, and healthy controls were verified by Sanger sequencing.

Results: Novel compound heterozygous mutations c.800A > G and c.1074_1075delinsAT of POMT2 were revealed in one affected individual by clinical exome sequencing. There was no report of these two variants and predicted to be highly damaging to the function of the POMT2.

Conclusion: The novel variants extend the spectrum of POMT2 mutations, which promotes the prognostic value of testing for POMT2 mutations in patients with LGMD2N.