LAUSR

The SMPD4 gene encodes sphingomyelin phosphodiesterase 4, which preferentially hydrolyzes sphingomyelin over other phospholipids. The biallelic loss-of-function variants of SMPD4 have been identified in a group of children with neurodevelopmental disorder with microcephaly, arthrogryposis, and structural brain anomalies (NEDMABA). Here, we report a girl of Chinese ancestry with intrauterine growth restriction, microcephaly, postnatal developmental delay, arthrogryposis, hypertonicity, seizure, and hypomyelination on brain magnetic resonance imaging; biallelic null variants (c.1347C > G [p.Tyr449*]; Chr2 [GRCh37]: g.130877574_131221737del [whole-gene deletion]) were detected by whole-exome sequencing. Our case is the first report of NEDMABA of Chinese ancestry, confirming the involvement of SMPD4 in NEDMABA and expanding the mutation spectrum of this syndrome.