Homozygous but not heterozygous mutation c.281-1G>T has been previously reported to cause C7 deficiency.[19] The alanine-485 is well preserved in vertebrate animals, suggesting that the novel variant c.1454C>T (p.A485V) is contributing to C7 deficiency in a compound-heterozygous manner in our case. This evidence concerns the gene C7 and hyperinsulinemic hypoglycemia, familial, 4.