Alpha-fetoprotein and hypothyroidism in infants

To the Editor.— We recently have documented a relationship between serum α-fetoprotein (AFP) and congenital hypothyroidism (CH) in the newborn period. Previous studies in our laboratory and others had reported a relationship between elevated serum AFP and elevated thyroid-stimulating hormone (TSH)/low thyroxine T4 in newborns and infants in the first few months of life.1-4 The New York State Newborn Screening Program for CH routinely screens more than 300 000 specimens per year diagnosing 120 to 140 confirmed cases of CH annually.