[MIM 605 820, 617 158]

(GNE myopathy, distal myopathy with rimmed vacuoles, hereditary inclusion body myopathy type 2)

Estimated prevalence at 0,4-2/1,000,000 but more prevalent in Japan, in Jews of Iranian origin and Bedouin populations in Kuwait. Autosomal  dominant or recessive transmission of a mutation of the GNE gene (9p12-13), coding for UDP-N-acetylglucosamine-2/N-acetylmannosamine kinase involved in the synthesis of sialic acid, that plays an important role in the stabilisation of the glycoproteins in the skeletal muscle, and therefore in cell adhesion.

Clinical picture: onset around 20-30 years of age. Slowly progressive myopathy that first affects the tibialis anterior muscle (drop foot) but spares the quadriceps. It is associated to a distal amyotrophy. The muscles of the hand are affected later. The muscles of the pelvic (walking difficulties) and scapular girdles are affected last. In general, the patients become wheelchair-bound on average 15 years after disease onset.

CPK levels are mildly (2 to 5 times the normal level) increased. There is no respiratory nor cardiac involvement.

Biopsy: non-specific anomalies such as variation in the diameter of the fibers and signs of regeneration; sometimes: inclusion bodies  and rimmed vacuoles.

Anesthetic implications:

no reported cases so far; a priori, avoid succinylcholine and volatile halogenated agents (risk of rhabdomyolysis ?)

References : 

-        Aloraif H, Pogoryelova O, Al-Ajmi A, Alreyan LA et al.
GNE myopathy in the Bedouin population of Kuwait : genetics, prevalence, and clinical presentation.
Muscle & Nerve 2018; 58: 700-7.

Updated: March 2021