ASNS and microcephaly: The ASNSD is a newly described rare autosomal recessive neurodevelopmental disease.[1,3–5] In 2013, Ruzzo et al first reported 9 cases of ASNSD in 4 families with clinical manifestations of congenital microcephaly, developmental delay, progressive encephalatrophy, and refractory epilepsy; they confirmed ASNSD as a recessively inherited metabolic disorder caused by homozygous or complex heterozygous mutation(s) in the ASNS gene encoded by chromosome 7q21.[1] Herein, we report the first case of ASNSD in China.