Figure 1. The seven identified Brazilian families with STAT5B c.424_427del mutation. Homozygous patients are indicated by black symbols, heterozygous carriers by gray symbols and non-carriers by white symbols. Red symbols represent the individuals identified through an active search for this mutation in the city of Criciúma. The symbol * refers to two individuals with severe pulmonary disease of unknown etiology. In family 3, the diagnosis of homozygosity for STAT5B c.424_427del mutation in the two deceased siblings was inferred from their clinical data and from the finding that their parents are heterozygous carriers.