AdvertisementParents Lobby States To Expand Newborn Screening Test For Rare Brain DisorderOctober 04, 2017Anna GormanfacebookEmailKerri De Nies plays with her son, Gregory Mac Phee at their home in San Diego. Gregory tested positive for adrenoleukodystrophy, a rare brain disorder that affects 1 in about 18,000 babies. Roughly 30 percent of boys with the genetic mutation go on to develop the most serious form of the disease. (Anna Gorman/KHN)