A Case of GNE Myopathy Presenting a Rapid Deterioration during Pregnancy

Abstract

BackgroundGNE myopathy is characterized by early-adult-onset distal myopathy sparing quadriceps caused by mutations in the GNE gene encoding UDP-N-acetylglucosamine 2-epimerase/N-acetylmannosamine kinase, an enzyme in the sialic-acid synthesis pathway.Case ReportA 27-year-old Korean woman presented a rapid deterioration in strength of the distal lower limbs during her first pregnancy. She was diagnosed with GNE myopathy and carrying the compound heterozygous mutations of the GNE gene (D208N/M29T).ConclusionsThis is a representative case implying that an increased requirement of sialic acid during pregnancy might trigger a clinical worsening of GNE myopathy.

Clinical and Electrophysiological Findings in Hereditary Inclusion Body Myopathy Compared With Sporadic Inclusion Body Myositis

“…26 Pure myopathic changes sparing the quadriceps were also described. 19,21,23 Neurogenic MUPs were reported in 2 additional GNEhIBM cases. 15 Overall, we did not find any difference between the 2 groups in the distribution of reinnervation (long-duration, high-amplitude) MUPs, CRDs, or frequency of myotonic discharges.…”

“…13 Reported description of the electromyographic (EMG) findings in genetically proven hIBM patients show some resemblance to those encountered in sIBM with essentially mixed myopathic and neurogenic features. 9,[13][14][15][16][17][18][19][20][21][22][23][24][25][26] In this study, we describe the clinical and electrophysiological features of hIBM subjects in comparison with their sIBM counterparts to identify differences that might help the clinical differential diagnosis.…”

Phenotypic stratification and genotype–phenotype correlation in a heterogeneous, international cohort of GNE myopathy patients: First report from the GNE myopathy Disease Monitoring Program, registry portion

“…However, the women enrolled in the registry tend to have an earlier onset on average than men, which has not been previously reported. A possible explanation could be that there is an aggravating effect of pregnancy on muscle strength in general and possibly by increased requirement of Sialic acid during pregnancy [22] .…”

Pregnancy in GNE Myopathy Patients: A Nationwide Repository Survey in Japan

“…For instance, in a study in Thailand, 3 GNE myopathy patients developed rapid deterioration of muscle weakness during pregnancy [11]. Similarly, the development of myopathy was noted in an Egyptian patient [12] and a Korean patient [13] during their rst pregnancies. While these studies suggest the possibility that pregnancy may trigger disease onset, there have been no reports on maternal and newborn complications and disease progression after delivery.…”

“…The impact of pregnancy or delivery on disease progression is a matter of great signi cance. A total of 7 patients were previously reported to have developed GNE myopathy during pregnancy [11][12][13].…”