INTS11 is a critical catalytic component of the Integrator complex that regulates RNA polymerase II termination and modulates gene expression. Until recently, INTS11 mutations were associated with human neurodevelopmental disorders, characterized by global developmental and language delays, generalized hypotonia, and progressive brain atrophy.

We report the case of a 2-year-old Chinese girl who presented with global developmental delay, generalized hypotonia, refractory epilepsy, craniofacial dysmorphism, and progressive brain atrophy. Novel variants were identified in exon 2 of INTS11 gene c.588_589del (p. Trp197AspfsTer2) and c.457_459del (p. Glu153del).

We identified a compound heterozygous mutation in INTS11, a clinical feature consistent with two previous reports of the variants in human INTS11, but her recurrent seizures were more pronounced and refractory to most antiepileptic drugs and ketogenic diets.