case_images: PMC7750344_01
case_images: PMC7750344_02
case_images: Family pedigree and nucleotide sequence of the GCK gene showing a homozygous deletion mutation (c.1255delT; p.Phe419Serfs*12)
case_images: TPA-55-434-g001.jpg
case_images: PMC7750344_02_TPA-55-434-g001.jpg
case_images: F1
case_images: In other family members with mild hyperglycemia, GCK gene analysis was performed and both parents and brothers were determined to be heterozygous for this mutation (Fig. 1).