351. Barger-Lux MJ, Heaney RP, Dowell S, Chen TC, Holick MF. 360. Holick MF. Vitamin D deficiency. Vitamin D3 and calcidiol are not equipotent. Researchers are performing to ascertain which genes lead to the particular developmental and actual physical variances that occur with 48,XXXY syndrome. Although many genes are distinctive to the X chromosome, genes in the pseudoautosomal areas are current on the two sex chromosomes.