Of those individuals presenting with primary HLH, we analyzed 23 samples in total (20 samples of 10 individuals with UNC13D deficiency; 1 sample of 1 individual with STXBP2 deficiency; 2 samples of 1 individual with RAB27A deficiency, Table 2). This evidence concerns the gene STXBP2 and hyperinsulinemic hypoglycemia, familial, 4.