Despite the fact that the role of ethnicity in the variable incidence of SIDS among countries could be due to different socioeconomic environments and caregiving and child-rearing practices, still the virtual absence of the c.552T-c*161A haplotype in the Asian population, where SIDS incidence is very low, and the highest frequency in Africans, characterized by a high SIDS incidence (36, 37), sustain a role of PHOX2B in the etiology of these events. The gene discussed is PHOX2B; the disease is sudden infant death syndrome.