ESPE Abstracts

Background: Congenital hypothyroidism (CH) characterized by a deficient secretion of thyroid hormone in newborn. It is the most common endocrine disease in the children with an incidence rate about 1: 3000 live births in Saudi Arabia. Thyroid dysgenesis and dyshormonogenesis are the most common causes. Thyroid dyshormonogensis commonly inherited as autosomal recessive disorders. Although Thyroglobulin followed by TSHR mutations are the most common genetic defects in Saudi patients, there was no enough data regarding their clinical manifestations and management of these cases.

Method: A retrospective cohort study, conducted at King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia. Including 10 patients who genetically confirmed to have CH secondary to Thyroglobulin gene mutation. Medical Charts were reviewed for clinical, biochemical and radiological data.

Result: 4/10 patients (40%) presented with goiter antenatally and received multiple intra-uterine Thyroxin injection, 8/10 (80%) presented with enlarged goiter and 5/10 (50%) with growth retardation. Biochemically, they all presented with high TSH and low fT4. Interestingly, all patients have persistently high TSH level even with upper-normal level of fT4 (P = 0.0022) while on excellent dose of L-Thyroxin. We found 3 previously reported homozygous mutation in TG gene. One patient has compound heterozygous likely pathogenic mutation.

Conclusion: This study is the largest cohort series to date describing the clinical and molecular features of CH secondary to Thyroglobulin gene mutation worldwide, as well as their management and prognostic indicators. It will contribute significantly to the understanding of genetic mutations underlying the congenital hypothyroidism related to thyroglobulin mutation in Saudi population.