info:eu-repo/semantics/publishedVersion
Mutations in Thyroid Hormone Beta Receptor Gene Identified in Children with Clinical Resistance to Thyroid Hormones
Fecha
2020Registro en:
Mutations in Thyroid Hormone Beta Receptor Gene Identified in Children with Clinical Resistance to Thyroid Hormones; XXVIII Congreso Latinoamericano de Endocrinología Pediátrica
; Florianópolis; Brasil; 2019; 52-52
1663-2818
CONICET Digital
CONICET
Autor
Gonzáles, Viviana
Balbi, Viviana A.
Morin, Analía
Reinoso, Andrea
Vitale, Laura
Ricci, Jaime
Espósito, Mariela
Martín, Rodrigo
Tournier, Andrea L.
Adrover, Ezequiela
Molina, Maricel Fernanda
Targovnik, Hector Manuel
Rivolta, Carina Marcela
Resumen
Introduction: Patients with resistance to thyroid hormones(RTH) show different clinical features. Several mutations have been identified in them.Objective:To describe patients followed up since 2006 with RTH suspicion evaluated for mutations in thyroid hormone beta receptor(THRß)gene.Methods:Children were followed up in our Endocrinology Department.Patient 1:10-yr-old boy with elevated T3, T4 and free T4, normal TSH in routine thyroid testing requested for overweight. Patient 2:0.7-yr- old boy with Down syndrome and elevated T3, T4 and free T4, normal TSH.Patient 3:Boy with abnormal results on neonatal screening, with elevated T3, T4, free T4 and TSH.Patient 4:4.7?yr-old girl with elevated T3, T4 and free T4, normal TSH in routine thyroid testing requested for low weight.Patient 5: 1-yr- old boy with elevated T3, T4 and free T4, normal TSH in routine thyroid testing requested for low weight.Patient 6:Boy with congenital hypothyroidism diagnosed by screening with elevated T3, T4, free T4 and TSH.Clinical manifestations:Patients 1, 4 and 5 showed palpitations, tachycardia.Familial antecedents: Patient 3 has two brothers with similar RTH profile. Patient 4 had a sister who died at 3 months of age and mother with confirmed RTH. Patient 6 had an aunt with RTH profile.Thyroid ultrasound. All patients had normal gland size except patient 6 who had an hypoplastic gland. Patient 4 showed goiter at follow up.Treatment:Patient 1 received metimazol; patients 1,4 and 5 beta blockers and patient 6 levothyroxine.Molecular biology analysis: genomic DNA was isolated from blood cells and the exons 7-10 of the THRß gene, including the flanking intronic regions were amplified by PCR. DNA sequences from each amplified fragment were performed with the Taq polymerase-based chain terminator method and using the specific forward and reverse THRß primers. Results.Direct sequence analysis revealed a novel missense mutation in exon 10 in patient 3, c.1329G>T transvertion that results in a p.K443N substitution and two known missense mutations: c.1357C>A, p.P453T (Patient 1)in exon 10 and c.949G>A, p.A317T (Patient 4) in exon 9.Conclusion:THRß gene mutations were found in half of the patients with RTH, including a new mutation.Although goiter is a common feature in RTH, only one patient presented it.These findings support the importance of searching THRßgene mutations in suspected individuals to achieve an adequate follow-up and treatment in patients with RHT.