SLC22A2 and hyperinsulinemic hypoglycemia, familial, 4: Finally, screening for certain disorders such as Organic Cation Transporter 2 deficiency (OCTN2 deficiency, see Box 1C) (11, 12) might detect mildly affected or asymptomatic mothers, because abnormal biomarkers in the neonate can be caused by an aberrant biochemical profile in the mother.