Very rare, recently described. Consequences of a mutation of the gene coding for asparaginyl-tRNA synthetase (18q21.31), which belongs to class IIa of tRNA synthetases.

A distinction is made between:

1)        NEDMILG (acronym for NEurodevelopmental Disorder with Microcephaly, Impaired Language, and Gait abnormalities) [MIM 619 091], autosomal recessive transmission: delayed walking and gait disorders, intellectual retardation with delayed or absent language, progressive microcephaly. Occasionally hypotonia, early-onset convulsions, peripheral sensorimotor neuropathy (demyelinating or axonal).

2)        NEDMILEG (NEurodevelopmental Disorder with Microcephaly, Impaired Language, Epilepsy, and Gait abnormalities) [MIM 619 092], autosomal dominant: delayed walking and gait disorders (with ataxia and spasticity), intellectual delay with delayed or absent language, progressive microcephaly, early-onset convulsions, demyelinating peripheral sensorimotor neuropathy. Presence of facial dysmorphism: receding forehead, wide jaw with retrognathia, midface hypoplasia, dysmorphic and low-set ears, hypertelorism with upslanting palpebral fissures, thin upper lip and everted lower lip, wide-set teeth, trumpet nose, long fingers, clinodactyly, syndactyly.

A loss-of-function mutation in the same gene can lead to autosomal dominant Charcot-Marie-Tooth disease (see this term).

Anesthetic implications:

management of a child with mental retardation, epilepsy, risk of difficult intubation in the autosomal dominant form; difficult peripheral venous access

References : 

-        Nonkulovski D, Sulejmani H, Memeti S.
Neurodevelopmental disorder associated with NARS1 gene mutation in a child with cerebral palsy.
Int J Res Med Sci 2024;12:1702-5.

-        Hasija N, Lees J.
NARS1-related disorder-An Orphan disease.
Pediatr Anesth 2025; 35:325-6

Updated: March 2025