title: Age-related probability of development of hereditary medullary thyroid carcinoma.
abstract: Hereditary medullary thyroid carcinoma is inherited as an autosomal dominant trait; at birth each child of an affected parent has a 50% chance of developing the disease. Measurement of plasma calcitonin concentrations after provocative calcium or pentagastrin stimulation has proved useful in the early diagnosis of this disease. To determine the age-related risk of conversion from a negative to a positive provocative test, 445 members of 11 kindreds were studied with sequential tests. Of 159 family members with a 50% risk at birth of developing medullary thyroid carcinoma 38 converted from a negative to a positive test result (mean age of conversion was 15 years). By means of methods previously described for determining the age-related probability for developing Huntington chorea, we present a method for determining the probability of development of medullary thyroid carcinoma. An individual at risk whose test result was negative had the following probability of converting to a positive test result at a later date: age (years)/probability, 0/0.5; 5/0.49; 10/0.41; 15/0.25; 20/0.16; 25/0.10, 30/0.05; and 35/0. We conclude that hereditary medullary thyroid carcinoma is regularly detectable in the pediatric age group and that screening should begin by age 5 years and be continued at regular intervals until age 35.
mesh_terms: D000293:Adolescent; D000328:Adult; D000367:Age Factors; D002116:Calcitonin / Q000097:blood; D002277:Carcinoma / Q000175:diagnosis / Q000235:genetics*; D002648:Child; D002675:Child, Preschool; D005817:Genetic Counseling; D006801:Humans; D011446:Prospective Studies; D012306:Risk; D013964:Thyroid Neoplasms / Q000175:diagnosis / Q000235:genetics*
chemical_list: D002116:Calcitonin