Clinical and molecular characteristics of Thai patients with achondroplasia.

Achondroplasia is an autosomal dominant disorder characterized by disproportionately short stature, frontal bossing, rhizomelia, and trident hands. Most patients appear sporadically resulting from a de novo mutation associated with advanced paternal age. A glycine to arginine mutation at codon 380 (G380R) of the fibroblast growth factor receptor 3 gene (FGFR3) was found to be the most common cause of achondroplasia in various populations. We identified and clinically characterized 3 Thai patients with achondroplasia. In all of them, we also successfully identified the G380R mutation supporting the observation that this is the most common mutation in achondroplasia across different ethnic groups including Thai.

Does GnRH analog improve the final height in Thai girls with idiopathic central precocious puberty?

Ten Thai girls with idiopathic central precocious puberty (ICPP) were treated with gonadotrophin releasing hormone (GnRH) analog for a mean period of 1.5+/-0.4 years. The predicted adult height at the end of treatment was significantly higher than that at the start of treatment (158.2+/-7.9 vs 153.0+/-8.7 cm, p=0.009). In addition, treatment with GnRH analog could significantly regress the breast staging from 3.4+/-0.8 to 2.6+/-1.0 (p=0.04),but not the pubic hair staging. Five of them reached a final height which was not significantly higher than the predicted adult height before treatment (153.1+/-4.8 vs 150.7+/-1.0 cm, p=0.5). In conclusion, treatment with GnRH analog in Thai girls with ICPP can improve the predicted adult height and regress the breast staging. However, the improvement of final height is not promising.

A cost-benefit of gnRH stimulation test in diagnosis of central precocious puberty (CPP).

The GnRH stimulation test is the gold standard to diagnose central precocious puberty (CPP). Conventionally, we need at least 2 hours to finish the test which seems to be costly and time consuming. In this study, we described the pattern of LH and FSH levels during the GnRH test in 27 girls who presented with various degrees of precocious puberty. We found that the blood samples at 90 and 120 min after GnRH were not necessary. To save the cost of diagnosis, the basal LH/FSH ratio > 0.2, the 30 min LH/FSH ratio after GnRH > 0.9 and the peak LH/FSH ratio > 1.0 can be used to diagnose CPP with positive predictive values (PPV) of 87.3, 89.4 and 93.8 per cent respectively.

Establishing gas chromatography-mass spectrometry to diagnose organic acidemias in Thailand.

Disorders of organic acid metabolism are a group of disorders which has long been ignored by majority of Thai physicians. Part of this is due to lack of laboratories in Thailand to verify the diagnosis of the disorders. We have recently developed a technique to qualitatively analyze organic acids utilizing Gas Chromatography-Mass Spectrometry (GC-MS). Eight patients in four families were successfully identified as having organic acidemias (OA) by this method. Two families had methylmalonic acidemia, one had propionic acidemia, and the other had 3-methylcrotonyl CoA carboxylase deficiency. To our knowledge, this is the first laboratory in Thailand being able to use GC-MS to diagnose OA. Availability of a laboratory in Thailand and affordability of the test are expected to result in earlier diagnosis and identification of more cases of OA in Southeast Asian countries. Consequently, prompt and proper treatment can be anticipated which should lead to better prognosis for patients with this group of disorder.