RU2487 is heterozygous for a de novo p.Gln703X allele in BSN. At the time of the last assessment, she was a 23-year-old Latina woman with a history of severe obesity and type 2 diabetes mellitus diagnosed at age 19 years at which time her HbA1c was 7.4%. Here, BSN is linked to obesity due to melanocortin 4 receptor deficiency.