CSNK1G1 encodes casein kinase 1 gamma 1, a serine/threonine-protein kinase that serves dual roles in normal and pathological biology. The gene produces two splice variants with distinct tissue distributions: the shorter isoform (CSNK1G1S) is predominantly testis-expressed, while the longer variant (CSNK1G1L) shows ubiquitous expression 1. Functionally, CSNK1G1 participates in cellular growth and morphogenesis through its role in Wnt signaling pathway regulation and phosphorylation of multiple substrates including N-methyl-D-aspartate receptors, supporting synaptic transmission in the brain 2. De novo heterozygous variants in CSNK1G1 cause syndromic developmental delay and autism spectrum disorder, with all five reported patients exhibiting developmental delay, dysmorphic facial features, and at least three showing autism spectrum disorder diagnosis 2. Beyond monogenic disease, CSNK1G1 shows pleiotropic involvement in complex disorders—genome-wide association studies identified CSNK1G1 as a novel shared genetic locus linking schizophrenia and inflammatory bowel disease, with genetic predisposition to schizophrenia showing causal association with increased IBD risk 3. Circular RNAs derived from CSNK1G1 function as oncogenic competitors in cancer progression. Circ-CSNK1G1 promotes thyroid cancer and triple-negative breast cancer by sponging miRNAs (miR-149-5p and miR-28-5p), thereby relieving suppression of downstream oncogenic targets (MAPK1 and LDHA) 4, 5. Similarly, circ0001955 derived from CSNK1G1 drives cervical cancer tumorigenesis via the miR-188-3p/NCAPG2 axis 6, establishing CSNK1G1 as a multi-functional regulator across neurodevelopmental, immunological, and malignant disease contexts.