Aim: To identify the LHR gene mutation in a prepubertal child with testotoxicosis.
Methods: Standard RIA procedure was used for estimating LH, FSH and testosterone levels. Molecular analysis was done by standard PCR using different sets of primers and reaction conditions specific for the LHR gene. Direct sequencing was done using the ABI Prism Dye terminator sequencing kit and the ABI 310 sequencing apparatus.
Results: We found a heterozygous mutation of the LHR gene in exon 11 of the second transmembrane region, Met-->Thr at the 398 position (M398T). The same mutation was also found in the proband's mother.
Conclusion: To our knowledge, this is the first molecular characterization of maternally inherited testotoxicosis in a 5 1/2-year-old boy from the Indian subcontinent.