rs2042126

Genome-wide association study of 2,323 Australian twins identified several associations with sleep phenotypes including sleep latency, sleep quality, sleep duration, and insomnia, but no genome-wide significant variants. Most notable finding: SNPs in CACNA1C intron 3 (rs7316184, rs7304986, rs7301906, and others) showed strongest association with sleep latency (p = 1.3 × 10⁻⁶), though this did not replicate in independent Chronogen Consortium sample. Additional associations with insomnia factor score (rs11174478 in SLC2A13, p = 1.92 × 10⁻⁶) and sleep duration (rs4780805, p = 2.66 × 10⁻⁶) were identified but remain unreplicated.