CACNA2D1 encodes a protein in the voltage-dependent calcium channel complex, which is essential in neurotransmission, and is associated with epilepsy [49], intellectual disability [50], and cardiac arrhythmias [51] which are conditions with an increased prevalence in 45,X [3, 12, 52]. This evidence concerns the gene CACNA2D1 and chronic obstructive pulmonary disease.