Clinical assessment of HNF1A and GCK variants and identification of a novel mutation causing MODY2

A child with impaired fasting glucose was found to be heterozygous for a novel variant at c.659G>A in GCK and a variant at c.1663C>T in HNF1A. Structural modeling and clinical correlation suggests that the GCK variant causes monogenic diabetes while the variant in HNF1A is unlikely to be pathogenic.