[Mutation of the RET proto-oncogene in type 2A multiple endocrine neoplasia Chinese families and the application of pentagastrin stimulation test in diagnosis and follow-up].
OBJECTIVE
To detect the mutations of RET proto-oncogene in two Chinese families with multiple endocrine neoplasia type 2A (MEN2A) and to study the clinical application of pentagastrin stimulation test in the diagnosis and follow-up of MEN2A.


METHODS
In this study, there were 4 patients clinically diagnosed as MEN2A in the two pedigrees. PCR and direct gene sequencing of PCR products with an automated DNA sequencer were used to scan the entire 21 exons of RET proto-oncogene in the leukocyte DNA of 6 members of the two families. Blood calcitonin was measured and pentagastrin stimulation test carried out in all the 4 clinically diagnosed patients.


RESULTS
Two missense mutations were detected in exon 11 of the RET proto-oncogene. One was C634R in the 2 patients from one MEN2A family and the other was C634Y in 2 patients from another family. The basal serum calcitonin was very high (400.5 - 13 510.7 ng/L, normal range 16.6 - 132.8 ng/L) in the MEN2A patients and after pentagastrin stimulation the serum calcitonin level was significantly higher (494.1 - 33 901.9 ng/L).


CONCLUSIONS
Two mutations (C634R and C634Y) were detected in the patients of two families with MEN2A. Pentagastrin stimulation test was helpful for the diagnosis and follow-up after operative treatment of MEN2A.
Yao
Bin
B
Department of Endocrinology, the First Affiliated Hospital of Sun Yat-sen University, Guangzhou 510080, China.
Liu
Xue
X
Chen
Xiong
X
Dong
Ting-ting
TT
Liang
Hua
H
Weng
Jian-ping
JP
D000328:Adult; D001483:Base Sequence; D002116:Calcitonin / Q000097:blood; D004252:DNA Mutational Analysis; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D018813:Multiple Endocrine Neoplasia Type 2a / Q000175:diagnosis / Q000235:genetics*; D020125:Mutation, Missense; D010375:Pedigree; D010418:Pentagastrin / Q000008:administration & dosage; D016133:Polymerase Chain Reaction; D000090063:Proto-Oncogene Mas; D051096:Proto-Oncogene Proteins c-ret / Q000235:genetics*
C000715470:MAS1 protein, human; D000090063:Proto-Oncogene Mas; D002116:Calcitonin; D051096:Proto-Oncogene Proteins c-ret; D010418:Pentagastrin