Conclusion;
Our case represent aid to other collegues in clinical suspicsion and diagnosing cases of RTH in addition to differentiation of RTH-alpha and RTH-beta. However the most interresting part in our case is the genetic study which revelaed a rare mutation in thyroid hormone receptor beta which have been only reported in very few cases before(heterozygous in THRb gene for sequence variant designated c.1147C>T, which is predicted to result in amino acid substitution p.Arg383Cys ) . While we suspect this variant could be pathogenic, at this time clinical significance of this variant is uncertain due to lack of conclusive functional and genetic evidence.