P-67 TWO RARE GENETIC DISORDERS IN ONE CASE ‘’ALLAN-HERNDON-DUDLEY-SYNDROME’’ AND’ “TREACHER COLLINS SYNDROME’’:A CASE REPORT
Authors: Yılmaz Ezgi , Güngör Kağan , Tamer Gonca 
Published: January 2025

Abstract

Introduction
Resistance to thyroid hormone syndrome (RTH), also named Refetoff Syndrome is an autosomal dominant or recessive rare genetic disease. It’s incidence is approximately 1:50.000 in newborns. Increasing awareness and knowledge about RTH will increase the diagnosis rate. So that other genetic diseases that accompany can be detected with early genetic consultation.

Clinical Case
A 45-year-old female patient was consulted to the endocrinology department for abnormal thyroid function tests. In her medical history, she had no known disease and no medication she used regularly. Her TSH level was 1,26 mıU/L(0,45-4,31), fT4:1,94ng/dl(0,85-1,70 ng/dl), fT3:5,73 ng/L(2-4,4). Thyroid autoantibodies were negative. In pituitary MRI, nodular formations that were hypointense compared to normal tissue were observed on the right and left sides of the pituitary (microadenoma?). Anterior pituitary hormones within the normal range. Heterophile antibody was negative. RTH or TSHoma was considered. She was admitted to the service for further examinations. Alpha subunit level could not measured. Basal TSH was found to be 1,49mU/L (0,54-4,31). A TRH stimulation test was performed on the patient and end of the test TSH was found to be 14.6 mıU/L. T3 supression test was performed. End of the test TSH was &lt;0,1 mıU/L. Thyroid hormone resistance was considered. During the patient’s medical history there were no signs of hyperthyroidism other than fatigue. In patient's genetic analysis heterozygous c.401A&gt;C:p variant detected in the THRB gene. NM_006517.5:C.401A&gt;C:p.(Glu134Ala) missense variant heterozygous was detected in SLC16A2 gene and was associated with the ‘’Allan-Herndon-Dudley Syndrome’’ phenotype. The NM__001371623.1;C.2998G&gt;A:p(Glu1000Lys)rs755763024 missense variant was observed heterozygous in the TCOF1 gene and was associated with the ‘’Treacher Collins Syndrome 1’’phenotype. Thyroid function tests were performed to the daughter and sons of the patient (table2). Genetic counseling was recommended to the patient and her family. There in no phenotypic features of ‘’Allan-Herndon-Dudley Syndrome ‘’ and Treacher Collins Syndrome ‘’ detected in the patient. Ophthalmology, otorhinolaryngology and cardiology examination was normal. The patient was diagnosed as RTH. She was clinically asymptomatic and discharged with plans to remain under medication-free monitoring.

Conclusion
As far as the literature is examined there is no previous case of the coexistence of TCS with RTH and other thyroid function test abnormalities. More case reports are needed to determine whether the coexistence of these two rare diseases is coincidental or related. According to previous literature information AHDS is usually clinically asymptomatic in women. But it is with RTH in the female patient in this case. As in the case, it is important to perform genetic screening and provide genetic counseling to the patients and family members.Table 1:Thyroid Function Tests of the Patient Table 2:Family Members Thyroid Function Test Results (1 daughter and 3 son of the patient)