Coffin-Siris Syndrome (CSS) is a rare neurodevelopmental disorder characterized 
by intellectual disability, coarse facial features, hypoplastic digits/nails, 
and hypertrichosis. The genes causative of CSS mainly encode the SWI/SNF 
complex, which contributes to chromatin remodeling and regulates the access of 
transcriptional factors to specific gene sites. While ARID1B mutations account 
for a third of all CSS cases, the condition's phenotypic features vary widely. 
We document the case of a girl with CSS who presented with a variant facial 
appearance, global developmental delay with speech impairment, agenesis of the 
corpus callosum, funnel chest, and bilateral renal stones without hypertrichosis 
or hypoplasia of the fifth fingernail. Genetic analysis revealed that the 
patient had a novel heterozygous frameshift mutation c.2201dupG 
(p.Ser736Ilefs*27) on the ARID1B gene.