case_images: PMC6821475_01
case_images: Molecular analysis of genomic deoxyribonucleic acid identified a
  homozygous one-base pair deletion in exon 3 of the TSHB gene that
  creates a new restriction site for SnaBI. The wild-type allele remained
  undigested (321 bp), whereas the mutant allele was cut into two
  fragments of 235 (as shown in the figure) and 86 bp (not shown). Our
  patient is homozygous for this mutation. Both parents and his sister are
  heterozygous.
case_images: 0103-0582-rpp-2019-37-4-00017-gf1.jpg
case_images: PMC6821475_01_0103-0582-rpp-2019-37-4-00017-gf1.jpg
case_images: f1
case_images: Peripheral blood was also collected from his parents and only sister, which resulted as heterozygous carriers of the mutant allele and had normal concentrations of TSH and free T4, displayed three fragments of 321, 235 and 86 bp (Figure 1).