Based on the genealogical analysis results, the patient’s phenotype (excessive body mass and height, red hair), hypoglycemia episodes, a decrease in cortisol level, and the ethnicity of Perm’ Tatar, patient D. was diagnosed with OBAIRH, which was confirmed by molecular genetic analysis—Sanger sequencing of the regulatory region of the POMC gene (NM_001035256.3): a pathogenic c.-71+1G>A variant was detected in a homozygous state. This evidence concerns the gene POMC and Hypoglycemia.