The State of California was one of the first in the United States to implement screening for X-ALD in February 2016 via the measurement of C26:0-lysophosphatidylcholine (C26:0-LPC) in a two-tier method, followed by sequencing of the ABCD1 gene to complete the screening [1]. This evidence concerns the gene ABCD1 and X-linked adrenoleukodystrophy.