Data from: The prevalence of c.2268dup and detection of two novel alterations, c.670_672del and c.1186C>T, in the TPO gene in a cohort of Malaysian-Chinese with thyroid dyshormonogenesis

Objectives: The c.2268dup mutation in the thyroid peroxidase (TPO) gene is
the most common TPO alteration reported in Taiwanese patients with thyroid
dyshormonogenesis. The ancestors of these patients are believed to
originate from the southern province of China. Our previous study showed
that this mutation leads to reduced abundance of the TPO protein and loss
of TPO enzyme activity in a Malaysian-Chinese family with goitrous
hypothyroidism. The aim of our study was to provide further data on the
incidence of the c.2268dup mutation in a cohort of Malaysian-Chinese and
its possible phenotypic effects. Setting: Cohort study. Participants:
Twelve biologically unrelated Malaysian-Chinese patients with congenital
hypothyroidism were recruited in this study. All patients showed high TSH
and low fT4 levels at the time of diagnosis with proven presence of
thyroid gland Primary outcome measure: Screening of the c.2268dup mutation
in the TPO gene in all patients was carried out using PCR-direct DNA
sequencing method. Secondary outcome measure: Further screening for
mutations in other exonic regions of the TPO gene was carried out if the
patient is a carrier for the c.2268dup mutation Results: The c.2268dup
mutation was detected in 4 out of the 12 patients. Apart from the
c.2268dup and a previously documented mutation, c.2647C>T, two
novel TPO alterations namely c.670_672del and c.1186C>T were also
detected in our patients. In silico analyses predicted that the novel
alteration affect the structure/function of the TPO protein. Conclusion:
The c.2268dup was detected in approximately one third of the
Malaysian-Chinese with thyroid dyshormonogenesis. The detection of the
novel c.670_672del and c.1186C>T alterations expand the mutation
spectrum of TPO associated with thyroid dyshormonogenesis.