No abstract

Background GNE myopathy is an autosomal recessive adult-onset distal myopathy. While a few case reports have described the progression of GNE myopathy during pregnancy, to our knowledge, none have examined disease progression after delivery or obstetric complications. Objective This study aimed to reveal maternal complications, newborn complications, and the impact of pregnancy on disease progression in GNE myopathy patients. Methods We conducted a questionnaire survey on pregnancy, delivery, and newborns involving female GNE myopathy patients who are currently registered in a national registry in Japan. Results The response rate for the questionnaire survey was 60.0% (72/120). Of the 72 respondents, 44 (61.1%) had pregnancy experience (average, 1.8 pregnancies; 53 pregnancies before onset and 28 after onset). The incidence of threatened abortion was 26.9% among post-onset pregnancies, which was higher compared to those of the general Japanese population (p = 0.03). No other maternal or infant complications were commonly observed. Over 80% were unaware of changes in disease progression during pregnancy (mean age, 32.8 ± 3.5 years) or after delivery (32.9 ± 3.8 years), while 19.0% experienced disease exacerbation within a year after delivery (30.0 ± 1.0 years). Six patients developed myopathy within a year after delivery (29.7 ± 4.6 years), while none developed myopathy during pregnancy. Conclusions There were no serious maternal or newborn complications, and subjective progression did not differ during or after delivery in the majority of GNE myopathy patients. However, our findings suggest the importance of considering the possibility of threatened abortion and disease progression after delivery.

GNE myopathy has an estimated worldwide prevalence of 1/1 000 000 (Orphanet; https://www.orpha.net/conso r/cgi-bin/index.php) but is more common in Persian and Japanese populations. 1 It is an adultonset progressive myopathy which typically starts with foot drop and uniquely spares quadriceps until the late stage. [2][3][4][5] Rimmed vacuoles are frequently be found in atrophic fibers of affected muscles. 1 Model mice studies have led to the better understanding of molecular mechanism and multiple clinical trials. At the same time, natural history studies and patient registries have contributed much for the comprehension of GNE myopathy including extra-muscular manifestations. In this review, we summarize the evolving research on GNE myopathy and introduce more recently identified features.