SLC16A2 and hyperinsulinemic hypoglycemia, familial, 4: Studies have shown that despite the unusual pattern of TH serum concentrations in Mct8 deficiency [10,11,15,27], the HPT axis is deregulated differently in Mct8−/y mice of different ages, namely TSH serum concentrations are significantly [10,27] or only moderately enhanced in Mct8 deficiency [11,15,16].