| FDH is the most common cause of congenitally increase in serum total T4 in Caucasians, because of increased binding to abnormal serum albumin. The abnormality is autosomal dominantly inherited. Sunthornthepvarakul, Chicago, IL, USA, reported replacement of arginine by hystidine in codon 218 of the albumin gene in affected members of 8 unrelated families. It was concluded that the finding of the same mutation in these different families suggests a founder effect since the likelyhood of co-association by chance is less than 0.4 %. This result was also considered to be in agreement with the much higher prevalence of FDH in people of Hispanic origin. |
