| Budget Amount *help |
¥2,400,000 (Direct Cost: ¥2,400,000)
Fiscal Year 1987: ¥1,000,000 (Direct Cost: ¥1,000,000)
Fiscal Year 1986: ¥1,400,000 (Direct Cost: ¥1,400,000)
|
|---|
| Research Abstract |
It appears that the patients with isolated TSH deficiency have abnormal TSH <beta> gene, because secretion of gonadotropins (LH, FSH) and free TSH <alpha> are seen in these patients. We cloned and analysed the TSH <beta> gene of these patients. In comparison with normal TSH <beta> gene, we could find out the codon AGA(Arg) which is 1 bp substitution at the 29th amino acid instead of GGA(Gly). In order to analyze the dysfunction of the mutant TSH, the expression experiment of these mutant and normal TSH were performed, by use of mRNA microinjection technique into Xenopus oocyte. We could detect the complete TSH molecule by normal TSH <alpha> and TSH <beta> m RNA but not by normal TSH <alpha> and mutant TSH <beta> mRNA. To establish the method of diagnosis for this mutation, we note that this substitution generate the sequence -CTAG-, which is a cutting site of restriction endonuclease MaeI. Then, we could detect the mutant gene by genomic Southern hybridization after genomic DNAs were cleaved by MaeI. In this way, Southern hybridization data revealed that the patients with isolated TSH deficiency were homozygous with mutant TSH <beta> gene, the parents of these patients were heterozygous with mutant and normal TSH <beta> gene, and normal healthy man were homozygous with normal TSH <beta> gene. Congenital isolated TSH deficiency is an autosomal recessive disease, and these data follows to Mendelian rule. We become to be able to analyze the carrier of this disease, usingSouthern Hybridization with MaeI.
|
