TMEM70 and hyperinsulinemic hypoglycemia, familial, 4: As complex V deficiency in Roma families had been linked to TMEM70, initially described by Spiegel et al. [10], Sanger sequencing of TMEM70 detected the previously reported mutation c.317-2A>G in a homozygous form in the 3 affected children (children I, IV, and VI) (Figures 1(b)-1(c)).