Congenital Central Hypothyroidism due to a Homozygous Mutation in the TSHβ Subunit Gene

Figure 2

Molecular analysis of genomic DNA identified a homozygous one-base pair deletion (T313del) in exon 3 of the TSHβ subunit gene resulting in a frame shift and a premature stop at codon 114. The deletion of nucleotide 313 (T) creates a new restriction site for SnaBI. The allele with the wild-type TSHβ fragment remained undigested (344 bp), whereas the mutant allele was cut into two fragments of 251 (as shown in the figure) and 93 bp (not shown). Our patient (II1) is homozygous for this mutation, both parents (I1 and I2) are heterozygous.