Myophosphorylase deficiency (McArdle disease) in a patient with normal pregnancy and normal pregnancy outcome

Abstract

Summary:McArdle disease is a rare, mostly autosomal recessive disorder of deficient myophosphorylation of glycogen in skeletal muscles. Recent knowledge regarding this condition means that women of childbearing age with McArdle disease can expect to labour normally without ill effect. We report a case of a 30-year-old woman in her first pregnancy who had an episode of exerciseinduced myoglobinuria with a significant rise in serum creatine kinase (CK) levels in early pregnancy who then laboured normally but did require a caesarean section for a malposition of the fetal head.

McArdle Disease and Pregnancy

“…In a series of 20 pregnancies in 14 women, published in 2010, an improvement was seen in 13 of the patients 7 . Two other individually described cases also improved during pregnancy 5,6 . There are more pregnancies described, but there is not enough data to know if there was an improvement of the symptoms [8][9][10][11][12] .…”

“…There are more pregnancies described, but there is not enough data to know if there was an improvement of the symptoms [8][9][10][11][12] . Pregnancy is not defined as a risk factor in McArdle disease and normal delivery is not contraindicated [5][6][7][8] .…”

“…The reported case illustrates these situations, where the patients frequently ignore the symptoms. Also, there are only a few described cases of pregnancy and labour in patients with McArdle disease [5][6][7][8][9][10][11][12] . Therefore, the fact that this patient had two pregnancies can be helpful to understand the behaviour of this disease during pregnancy.…”

McArdle disease causing rhabdomyolysis following vaginal delivery

“…She was evaluated by the obstetric anaesthesia team antenatally and was advised to receive early epidural analgesia during labour, adequate hydration, strict glucose monitoring and to maintain a blood glucose level above 5.6 mmol.l −1 . Adequate peripartum glucose management is thought to help prevent myopathy in this population by obviating the need to break down glycogen stores , so she was specifically counseled to continue oral intake during labour.…”

“…McArdle disease (glycogen storage disease type V) is a rare, autosomal recessive disorder with an incidence of approximately 1:100,000 . The genetic mutation causes a defect in muscle glycogen phosphorylase, which can lead to symptoms of muscle fatigue during exercise and cause myoglobinuria, kidney injury and rhabdomyolysis .…”